When was the first televised NFL game?

NBC broadcast the first televised National Football League (NFL) game when they carried the 22 October 1939 game between the Philadelphia Eagles and the Brooklyn Dodgers. The same year, the first nationwide radio broadcast of an NFL championship game was carried on the Mutual Broadcasting System. While the NFL had weak television deals that ranked behind college football and even the Canadian Football League in the 1950s, the broadcast rights of the NFL would go on to become an important property following the 1958 NFL Championship and the later establishment of the American Football League in 1960. "Monday Night Football", "NFL on Fox", and "NBC Sunday Night Football" have changed the landscape of American football broadcasts, including the scheduling of the Super Bowl, transforming it from an afternoon broadcast into a primetime spectacle. The price for the NFL's broadcast rights has increased steadily over the past several decades, in part because of bidding wars between the numerous networks and the fear of losing stature due to the loss of NFL programming; as of the most recent contract the league nets annual fees of over $6 billion, or half of the league's overall revenue, from television rights alone. Four of the five major sports television units in the United States, and the four companies that control all of the major broadcast networks, currently own some NFL rights.

Broadcasting of sports events

The broadcasting of sports events (also known as a sportscast) is the live coverage of sports as a television program, on radio, and other broadcasting media. It usually involves one or more sports commentators describing the events as they happen.

Broadcasting of sports started with descriptions of play sent via telegraph in the 1890s. In 1896, a telegraph line was connected to the Victoria Rink in Montreal to update fans in Winnipeg of the Stanley Cup challenge series between Montreal and Winnipeg ice hockey teams. In 1923, the first radio broadcast of an ice hockey game took place on 8 February, with the broadcast of the third period of a game between Midland and North Toronto of the Ontario Hockey Association. Later that month, the first full-game broadcast took place in Winnipeg. That same season, hockey broadcasting pioneer Foster Hewitt made his first broadcast.

In 1933, Hewitt called a Canada-wide radio broadcast of an NHL game between the Detroit Red Wings and the Toronto Maple Leafs. Always starting the broadcast with "Hello, Canada, and hockey fans in the United States and Newfoundland!"; this phrase stuck around (albeit without the "Newfoundland" portion after the dominion confederated into Canada in 1949) all the way to CBC's first national television broadcast (the first actual broadcast was on closed-circuit in Maple Leaf Gardens in Spring 1952) of "Hockey Night in Canada" in October 1952. Today it is consistently among the highest-rated programs in Canada.

Broadcasting of the Canadian Football League has been a fixture of Canadian television since the CBC's debut in 1952. From 1962 (one year after the debut of CTV) through 2007, there were two separate CFL contracts: one for CBC, and one for CTV (or a sister channel such as cable outlet TSN). Terrestrial television broadcasts of CFL games ended in 2008, when TSN acquired exclusive TV rights to the league.

American sports broadcasts are widely available in Canada, both from Canadian stations and from border blasters in the United States. In order to protect Canadian broadcasters' advertising, broadcast stations can invoke simultaneous substitution: any cable or satellite feed of an American station broadcasting the same program as a Canadian broadcast station must be blacked out and replaced by the Canadian feed. This rule is part of the reason the NFL, which is broadcast on terrestrial television in the United States but has no direct presence in Canada, is also broadcast on terrestrial TV in Canada, while the CFL no longer is (the CFL is broadcast only on cable in the United States); the simultaneous substitution benefits are not extended to cable stations. For the purposes of regional sports broadcasting, the Toronto Blue Jays and Toronto Raptors both claim all of Canada as their "territory," allowing Blue Jays and Raptors games to be broadcast nationwide.

The first live commentary on a field sport anywhere in Europe was when Paddy Mehigan covered the All-Ireland Hurling Semi-Final between Kilkenny and Galway on 29 August 1926. This game is credited with being the first mainly because the BBC was prevented from broadcasting sporting events before 7.00pm as a means of protecting British newspaper sales.

The first sports event broadcast in the United Kingdom was a Rugby Union international between England and Wales, broadcast from Twickenham in January 1927. Two weeks later the first broadcast of a football match took place, with the BBC covering Arsenal's league fixture against Sheffield United at Highbury. Listeners to the broadcast could use numbered grids published in the Radio Times in order to ascertain in which area of the pitch (denoted as "squares") the action was taking place due to a second commentator reading out grid references during the match. This is believed to be the origin of the phrase "Back to square one."

The United Kingdom saw the first live television broadcast of a football match, with the BBC showing a specially arranged fixture between Arsenal and Arsenal Reserves on 16 September 1937.

The British media is dominated by national outlets, with local media playing a much smaller role. Traditionally the BBC played a dominant role in televising sport, providing extensive high-quality advertisement free coverage and free publicity in exchange for being granted broadcast rights for low fees. ITV broadcast a smaller portfolio of events, and Channel 4 broadcast a few events from the 1980s, mainly horse races and so-called minority sports. In the early 1990s this arrangement was shaken up by the arrival of pay-TV in the form of BSkyB. Their dedicated sports channels have since become the only place for some major sports to be seen. Starting in 2006 the Irish company Setanta Sports emerged as a challenger to Sky Sports' dominance of the British pay-TV sports market; however, Setanta's UK channel went into bankruptcy administration and off the air in 2009. Between 2009 and 2013 ESPN made an attempt to challenge Sky Sports before its British operations were bought out by Sky's current main competitor, BT Sport; a subsidiary of the former national telecommunications monopoly BT plc. There are also a dedicated UK version of Eurosport, called British Eurosport, and Eleven Sports.

Radio sports coverage is also important. BBC Radio 5 Live broadcasts almost all major sports events. It now has a commercial rival called Talksport, but this has not acquired anywhere near as many exclusive contracts as Sky Sports and dedicates much of its airtime to sports discussions and phone-ins; Absolute Radio has also begun acquiring sports rights. BBC Local Radio also provides extensive coverage of sport, giving more exposure to second-tier clubs which get limited national coverage.

National and local media both serve major roles in broadcasting sports in the United States. Depending on the league and event, telecasts are often shown live on network television (traditionally on weekends and during major events either national through a Television network, or in some cases, regionally syndicated by an operation such as Raycom Sports or a team), and nationally available cable channels (such as ESPN or Fox Sports 1). In some leagues (such as the NHL and the NBA), events are also primarily shown by regional sports networks groups (such as Fox Sports Networks), networks which air telecasts for teams of local interest, which are usually only carried within the relevant market. Additionally, cable channels also exist that are dedicated to specific types of sports, certain college sports conferences, or a specific league. Pay-per-view broadcasts are typically restricted to combat sports such as boxing, mixed martial arts or professional wrestling.

Radio broadcasts are extensive. The national leagues each have national network coverage of league high games in addition to local radio coverage originating with each team, with ESPN Radio and WestwoodOne controlling national rights to the major team sports and the motorsports circuits operating their own networks. Local radio broadcasts cover a wide variety of sports, ranging from the majors to local school and recreational leagues.

Internet broadcasts are also common, though college and major professional sports either use a pay wall or subscriber-based systems such as TV Everywhere to extract payment. Telephone broadcasts are rare, although a few companies provide the service.

In 1911, more than 1,000 people gathered in downtown Lawrence, Kansas to watch a mechanical reproduction of the 1911 Kansas vs. Missouri football game while it was being played. A Western Union telegraph wire was set up direct from Columbia, Missouri. A group of people then would announce the results of the previous play and used a large model of a football playing field to show the results. Those in attendance cheered as though they were watching the game live, including the school's legendary "Rock Chalk, Jayhawk" cheer.

The first voice broadcast of a sporting event took place on 11 April 1921 when Westinghouse station KDKA in Pittsburgh, Pennsylvania broadcast a 10-round, no decision boxing match between Johnny Dundee and Johnny Ray at Pittsburgh's Motor Square Garden. Prior to that, an experimental telegraph broadcast of the 1919 Lone Star Showdown was held on Thanksgiving Day of that year on experimental station 5XB, the predecessor of WTAW.

The first radio broadcast of a baseball game occurred on 5 August 1921 over KDKA from Pittsburgh's Forbes Field. Harold W. Arlin announced a game between the Pittsburgh Pirates and the Philadelphia Phillies. Two months later, on 8 October 1921, from the same Forbes Field, Arlin announced the first live radio broadcast of a college football game on KDKA when he gave the play-by-play action of the University of Pittsburgh victory over West Virginia University.

On 17 May 1939, the United States' first televised sporting event, a college baseball game between the Columbia Lions and Princeton Tigers, was broadcast by NBC from Columbia's Baker Field. (The world's first live televised sporting event had been the 1936 Summer Olympics in Berlin.) On 30 September 1939, the first American football game, a college contest between Fordham and Waynesburg College was broadcast on television. The first nationwide broadcast of college football, which was also the first live sporting event seen coast-to-coast, was a game between Duke University and the University of Pittsburgh that was televised by NBC on 29 September 1951. The broadcasting of college football games on television in the United States has been a fixture of the major networks on a continuous basis since that time. The NCAA severely restricted broadcasts of college football from the 1950s until a judge ruled that the action was a violation of antitrust rules in 1984, which allowed for a much greater expansion of college football broadcasting.

NBC also broadcast an NHL game in 1940; the league would briefly air games in the 1950s, but due to a dispute over how much of the rights fee money the players would receive (and difficulties programming around the two Canadian teams in the league at the time), the NHL refused to televise its games in the United States for six years in the 1960s. For this reason, as well as the regional nature of the sport, televised NHL games have struggled to gain a foothold on American television for the past several decades, trailing the other leagues in ratings. After several decades of bouncing around various networks (and a stretch from 1975 to 1994 when the league had no permanent broadcast partner), the NHL established a stable broadcast partner in 2004, when NBC and what was then Outdoor Life Network (now NBCSN) took over NHL broadcast rights; they have since renewed those rights through 2021.

The first-ever television broadcast of a basketball game occurred on 28 February 1940 when the University of Pittsburgh defeated Fordham at Madison Square Garden on NBC station W2XBS. Professional basketball has been aired on television since 1953, shortly after the founding of the National Basketball Association, and has been aired on television ever since. College basketball, on the other hand, was much later in gaining a television foothold. Although the NCAA Tournament has aired since 1962, it was not until the mid-1970s that regular-season college basketball games would air on major network television.

Outside of the networks, the only other source for national sports television was through early syndication networks. Sports Network Incorporated (SNI), later renamed the Hughes Television Network, carried Cleveland Browns (NFL) games in the 1950s and NHL games in the late 1970s, after the NHL lost its contract with NBC. TVS Television Network helped popularize the broadcasts of college basketball and also gave an outlet to the short-lived World Football League. Mizlou Television Network earned a reputation for carrying a large number of college football bowl games in an era when televised college football was highly restricted. Modern syndication networks still exist for sporting events, such as Raycom Sports and American Sports Network, both of which specialize in college sports.

The debut of ESPN in 1979 revolutionized the broadcasting of sports events. Within several years of ESPN's founding as a basic cable channel, it had developed a stable of sports broadcasts ranging from major leagues to oddities. ESPN has since grown into a massive multiplexed network, with several channels and a large news bureau that has led to the network bestowing the title of "Worldwide Leader in Sports" upon itself. Cable, and later digital cable and satellite, greatly expanded the number of channels (and, by extension, the room for broadcasting sports events) available on a given set, and also gave channels such as ESPN the ability to broadcast direct and nationwide, as opposed to dealing with local affiliates. Syndication networks gave way to regional sports networks, which carried broadcasts of local sports on a far greater scale than full-service broadcast stations could provide at the time; these combined with out-of-market sports packages (which debuted in the 1990s) allowed the carriage of these networks' sporting events across the country. However, with the increased availability of sports to broadcast came increasing rights fees, which could be recovered by the newly authorized practice of collecting retransmission consent fees from cable subscribers, which has led to numerous disputes and the dropping of channels from cable lineups. Individual leagues began launching their own networks in the 2000s; specialty networks of other sports have had varying levels of success.

One of the first live high-definition sports broadcasts in the U.S. took place in September 1998 in which a football game between Ohio State and West Virginia, aired on WBNS-TV. The station claims this to have been the first locally produced HD broadcast in the U.S.; however, as several other stations throughout the country also lay claim to this distinction, the veracity cannot be verified. It is widely considered the first ever live sports game in HD in the U.S. produced using a production truck and transmission vehicle from NHK, Japan's national public broadcasting organization.

The Internet has also allowed greater broadcasting of sports events, both in video and audio forms and through free and subscription channels. With an Internet broadcast, even a locally broadcast high school football game can be heard worldwide on any device with an audio output and an Internet connection. Individual leagues (including major ones) all have subscription services that allow subscribers to watch their sporting events for a fee.

One of the first live sporting events in the U.S. to be streamed was the Ohio State spring football game in 2001 by WBNS-TV. The game was delivered on RealVideo, a compressed video format, on the RealPlayer media player platform on the station's website. It also was distributed to Windows Mobile mobile devices using the Windows Media Player format, including Compaq's IPAQ personal digital assistant which required an ExpressCard to connect to the Internet.

Broadcasting rights and contracts limit who can show footage of the event.

In the United Kingdom BSkyB based its early marketing largely on its acquisition of the broadcast rights of the top division of the English league football, which as part of the deal with The Football Association broke away from The Football League to become the Premier League. This prevented the footage of any major Premier League football game being shown on free-to-air television until much later that evening (as highlights), something the European Commission were very unhappy about. Following warnings of legal action to stop the monopoly, an announcement was made that an alternative structure would be in place when the contract ended in 2007.

In the United States, team sports are broadcast by networks usually only in "game of the week" or championship situations, except for the NFL (see NFL on television) and motorsport. Other sports are broadcast by sports channels, and are limited by who can view them based on various rules set by the leagues themselves, resulting in blackouts. These limitations can be legally overlooked by purchasing out-of-market sports packages, such as MLB Extra Innings or NFL Sunday Ticket. Regular season games involving local teams (except the NFL) may also be viewed on those local stations or regional sports channels that have a contract to broadcast that team's games.

Events that have been described as "the most watched" per various definitions include the FIFA World Cup, Summer Olympic Games, Cricket World Cup, UEFA Champions League, Tour de France, Rugby World Cup (rugby union), Indian Premier League, Super Bowl, and the FIA Formula One World Championship.

TV Rights of the UEFA Champions League, per country. Season 2009-2010, according to FootBiz.In some countries, broadcast regulations referred to as "anti-siphoning laws" exist in order to ensure that coverage of major sporting events of national importance—often covering major events such as the Olympics, FIFA World Cup, and national team events in culturally-significant sports—are available on free-to-air, terrestrial television, rather than exclusively on pay television. Some larger events (particularly the Olympics) may be covered under rules allowing a portion of the event to be televised by a pay TV partner if a specific minimum of coverage is broadcast free-to-air, or if an extended highlights package is available on a delay to a free-to-air broadcaster.

In the United States, the Federal Communications Commission attempted to introduce similar restrictions on cable broadcasts of specific sporting events and recent films as to not cannibalize broadcast TV. In 1977, these restrictions were deemed to be invalid when a federal district court ruled that the FCC did not have the authority to make such decisions in a consolidated case, also noting that the constitutional basis for such a law had not been proven. No such laws have been passed since. Since then, sports have been a lucrative source of revenue in the U.S. pay television industry, including mainstream networks such as ESPN, as well as channels devoted to specific sports, leagues, and college sports conferences. These networks receive revenue from both advertising and carriage fees charged to television providers (and passed onto consumers as part of the cost of service), and can provide an outlet for expanded coverage of "niche" events with dedicated audiences.

By the mid-2000s and early 2010s, most major U.S. sports leagues (barring the National Football League, which has historically stipulated that all games be shown on terrestrial television in at least the markets of the teams involved) had begun to steadily decrease their presence on broadcast television, and allow more of their content (including post-season coverage in many cases) to air on cable networks, and more recently, digital-only outlets. The NCAA Division I Men's Basketball Tournament and national championship games in college football have also largely moved to cable (since 2016, the semi-finals of the former only air on broadcast television in odd-numbered years). A similar phenomenon has taken root in much of Canadian sport, where the Canadian Football League left broadcast television in 2008. The National Hockey League survives on Canadian broadcast television because Rogers Sportsnet, the cable broadcaster that acquired exclusive rights to the league in 2014, offers two weekly games to CBC Television for free to allow the network to continue the long-running "Hockey Night in Canada".

Pay-per-view

National General Sports Networks:

Spanish:

Specialty Sports Networks:

College Sports Networks:

Regional sports networks:Several sports teams in the United States have their own channels, or own shares in other sports networks. For example, the Boston Red Sox and Boston Bruins own New England Sports Network, which retains the New England area television broadcast rights for the majority of Red Sox games (except nationally televised games). The New York Mets own SportsNet New York jointly with Comcast and Time Warner Cable. Madison Square Garden has its own network as well, MSG, where they broadcast New York Rangers, New York Knicks, New York Islanders and high school sports games, as well as original shows. Altitude airs games of all Denver-based teams owned by Kroenke Sports Enterprises. Mid-Atlantic Sports Network is a partnership between the Washington Nationals and Baltimore Orioles.

The Longhorn Network, in which ESPN owns a stake, is even more specialized, designed as an outlet for the athletic program of the University of Texas at Austin (although it has also aired football games of the UT system's San Antonio campus).

Team-owned channels are also common in Europe, most notably Barça TV, Benfica TV, Galatasaray TV, Manchester United TV and Real Madrid TV.

NBC was the first major television network to cover an NFL game, when on October 22, 1939, it broadcast a game between the Philadelphia Eagles and the Brooklyn Dodgers; the network was still only in its infancy, with only two affiliates, the modern day WRGB (now a CBS affiliate) in Schenectady and W2XBS in New York City. Portions of that game still survive via films, but the film is not footage from the telecast (recordings of television broadcasts did not begin until 1948). The use of a sideline camera, the sole camera used in the 1939 broadcast, would become the standard for all future NFL broadcasts until 2017; the angle is particularly suited for estimating yardage, compared to more mobile camera angles that began to appear in the 21st century.

History of the National Football League on television

The history of the National Football League on television documents the long history of the National Football League on television. The NFL, along with boxing and professional wrestling (before the latter publicly became known as a "fake" sport), was a pioneer of sports broadcasting during a time when baseball and college football were more popular than professional football. Due to the NFL understanding television at an earlier time, they were able to surpass Major League Baseball in the 1960s as the most popular sport in the United States. Today, NFL broadcasting contracts are among the most valuable in the world.

Regular broadcasts of games began after World War II and the first NFL championship to be televised was the 1948 match between the Eagles and Cardinals.

In 1950, the Los Angeles Rams and the Washington Redskins became the first NFL teams to have all of their games—home and away—televised. In the same year, other teams made deals to have selected games telecast. The DuMont Network then paid a rights fee of US$75,000 to broadcast the 1951 NFL Championship Game across the entire nation.

From 1953 to 1955, DuMont also televised Saturday night NFL games. It was the first time that NFL fixtures were broadcast live, coast-to-coast, in prime time, for the entire season. The broadcasts ended after the 1955 season, when the DuMont Network folded. DuMont was a less than ideal partner for NFL broadcasts: with only eighteen affiliates in 1954, it was dwarfed by the amount of coverage the "Big Four" (later the East Division of the Canadian Football League) had with its contract on NBC, which had 120 affiliates at the time.

By 1955, NBC became the televised home of the NFL Championship Game, paying $100,000 to the league. The 1958 NFL Championship Game played at Yankee Stadium between the Baltimore Colts and the New York Giants went into sudden death overtime. This game, since dubbed the "Greatest Game Ever Played," was watched widely throughout the country and is credited with increasing the popularity of professional football in the late 1950s and early 1960s.

CBS began to televise selected NFL regular season games in 1956.

By 1959, big-market teams such as the Bears and Giants had all their games televised, but small-market ones like the Packers and 49ers still did not. Upon becoming NFL commissioner, Pete Rozelle worked to ensure that every team got all its games on TV.

When the rival American Football League (AFL) began in 1960, it signed a 5-year television contract with ABC. This became the first ever cooperative television plan for professional football, through which the proceeds of the contract were divided equally among member clubs. ABC and the AFL also introduced moving, on-field cameras (as opposed to the fixed midfield cameras of CBS and the NFL), and were the first to have players "miked" during broadcast games. As the AFL also had players' names stitched on their jerseys, it was easier for both TV viewers and people at the games to tell who was who.

As of the 1961 season, CBS held the rights to all but one of the NFL's teams; the Cleveland Browns had a separate contract with Sports Network Incorporated (SNI) to carry their games over a regional network. However, the Browns and SNI were forced to break their deal when the NFL and CBS devised their own revenue sharing plan after CBS agreed to telecast all regular season games for an annual fee of $4.65 million. A special antitrust exemption, the Sports Broadcasting Act of 1961, was passed in Congress to accommodate the collective contract, which restricted what days the league could televise their games. CBS' fee later increased to $14.1 million per year in 1964, and $18.8 million per year in 1966.

With NBC paying the AFL $36 million in 1965 to televise its games, and the intensified battle over college prospects, both leagues negotiated a merger agreement on June 8, 1966. Although they would not officially merge into one combined league until 1970, one of the conditions of the agreement was that the winners of each league's championship game would meet in a contest to determine the "world champion of football."

The first ever AFL-NFL World Championship Game was played on January 15, 1967 between the NFL champion Packers and the AFL champion Chiefs. As CBS held the rights to nationally televise NFL games and NBC had the rights to broadcast AFL matches, it was decided that both would cover that first game. The next three AFL-NFL World Championship Games, the initial Super Bowls, were then divided by the two networks: CBS broadcast Super Bowls II and IV while NBC covered III.

When the AFL and the NFL officially merged in 1970, the combined league divided its teams into the American Football Conference (AFC) and the National Football Conference (NFC). It was then decided that CBS would televise all NFC teams (including playoff games) while NBC would be responsible for all AFC teams. For interconference games, CBS would broadcast them if the visiting team was from the NFC, and NBC if the visitors were from the AFC. The two networks had a rotation policy for the Super Bowl.

ABC also agreed to televise one regular season game per week on Monday night. ABC aired its first edition of "Monday Night Football" on September 21, 1970. "MNF" pushed the limits of football coverage with its halftime highlights segment, occasional banter from Howard Cosell and Dennis Miller, and celebrity guests such as John Lennon, Arnold Schwarzenegger and Bill Clinton. During its 36-year run on ABC, "Monday Night Football" consistently ranked among the most popular prime time broadcasts each week during the season.

As the league's broadcasters, ABC, CBS, and NBC had their own talent. Announcers such as Cosell, Frank Gifford, and Al Michaels (from ABC); Pat Summerall and John Madden (from CBS); and Curt Gowdy, Dick Enberg, Marv Albert, Jim Simpson, Kyle Rote and Jim Lampley (from NBC), all had their own unique analysis of the game. Individual networks had distinctive innovations in their coverage. For example, CBS' "The NFL Today" was the first pre-game show to have a female co-host (Phyllis George). On December 20, 1980 NBC made history by broadcasting a game between the New York Jets and Miami Dolphins with no announcers. NBC has also tried one-announcer football when Dick Enberg called the New York Jets' visit to Cleveland Browns on December 12, 1981 without his regular colleague Merlin Olsen in accompaniment. NBC instead pre-recorded interviews with players and coaches from both teams which filled in the parts where Olsen would have spoken.

On December 27, 1987, NBC introduced the first female play-by-play football announcer in Gayle Sierens, who partnered with Dave Rowe in a game between the Seattle Seahawks and Kansas City Chiefs; contractual issues with her main employer prevented Sierens from calling any further games for the network, and it would be another 29 seasons before the next female announcer, Beth Mowins, began calling games for both ESPN and CBS in 2017.

In 1978, the NFL increased its revenue from both ticket sales and TV by expanding the regular season from 14 games to 16. Furthermore, the playoff format was expanded from 8 teams to 10 teams, enabling the league to give another post-season game each to CBS and NBC. This was partially due to the league's 1976 expansion to 28 teams.

Meanwhile, the Super Bowl became a yearly ratings blockbuster, allowing the broadcasting network to generate millions of dollars in advertising revenue. Four of the ten highest rating television broadcasts of all-time (in the U.S.) are Super Bowls. When the league signed a new 5-year TV contract with the three networks in 1982, it allowed ABC to enter into the Super Bowl rotation; Super Bowl XIX was ABC's debut. Since then, the network that televises each Super Bowl is determined by the contracts that the league negotiates with all of its broadcasters. Each network broadcaster generally gets one Super Bowl before any received a second. This process repeats before any network airs a third event, although the TV contracts usually expire by that time.

Cable TV became commonplace during the 1980s, and the NFL was eager to exploit that opportunity in 1987.

In 1986, the United States Football League, at the time pursuing an antitrust lawsuit against the NFL, signed an agreement with ESPN to carry games on Sunday nights. When the lawsuit failed and the 1986 season was canceled, the NFL swooped in and took the time slot, creating "ESPN Sunday Night Football" in 1987. ESPN thus became the first cable network to broadcast regular season NFL games. Chris Berman helped redefine the pre- and post-game shows when he launched "NFL Countdown" and "NFL Prime Time", and they have since become the top-rated pre- and post-game shows on television. The cable network's contract to show "ESPN Sunday Night Football" was one of the turning points in their growth, transforming them from a small cable network to a marketing empire.

When ESPN first started televising NFL games in 1987, it only broadcast Sunday night games during the second half of the season. Meanwhile, ABC, CBS, and NBC maintained their rights to "Monday Night Football", the NFC, and the AFC, respectively.

By 1990, Turner's TNT network started to broadcast Sunday night games for the first half of the season. The combined 1990 contracts with ABC, CBS, ESPN, NBC, and TNT totaled $3.6 billion ($900 million per year), the largest in TV history. One major factor in the increased rights fee was that the league changed the regular season so that all teams would play their 16-game schedule over a 17-week period. ABC was also given the rights to televise the two Saturday games on the opening weekend of the postseason. This was made possible after the league expanded its playoff format to include more teams.

TBS had also broadcast the infamous 1982 "strike" games. The NFLPA called for a players' strike three weeks into that season which reduced it to nine games. In October, two "all-star" exhibition games were held with generic NFC and AFC teams in Los Angeles and Washington, D.C. and aired on TBS. Ratings and attendance at both games was minimal.

In 1994, the league signed an exclusivity agreement with the direct broadcast satellite (DBS) service DirecTV to launch NFL Sunday Ticket, a satellite television subscription service that offers every regular season NFL game.

When contracts were signed in December 1993, CBS (which had been home to NFC games for 38 years) lost their rights to the fledgling Fox Network, and it just so happened that CBS also lost its MLB coverage (which it never recovered) after that same year. Fox offered a then-record $1.58 billion to the NFL over four years, significantly more than the $290 million per year offered by CBS. Fox was only seven years old and had no sports division, but it began building its own coverage by hiring many former CBS personalities such as Summerall and Madden.

Fox's NFL rights ownership made the network a major player in American television by attracting many new viewers (and affiliates) and a platform to advertise its other shows. In the meantime, CBS lost several affiliates (mainly owned by New World Communications in NFC markets) to Fox, and ratings for its other offerings languished. CBS lost a number of affiliates, primarily in Atlanta, Detroit, and Milwaukee, where it was dropped to lower-powered UHF affiliates unable to be received in some areas.

Due to satellite television, the NFL Sunday Ticket in local markets, and rules of the time, satellite subscribers were required to use antennas to pick up local affiliates. CBS was devastated by the loss of over-the-air availability of these stations in the outer reaches of some markets. Since 1994, the situations in Milwaukee and Atlanta have improved due to committed station ownerships and acquisition of high-profile syndicated programming, along with the digital transition equalizing the field into being received via UHF-only, while CBS's Detroit station continues to struggle for relevancy and exists mainly as an automated pass-through for CBS programming, along with shows from the network's syndication arm, CBS Television Distribution.

ABC, NBC, TNT and ESPN renewed their contracts in the meanwhile. TNT was able to get a stipulation that the Atlanta Falcons, based in Turner's home of Atlanta, be featured on TNT once a year, regardless of the previous season's record.

Meanwhile, NBC's rebound in the overall ratings in both the 1980s and 1990s after years at the bottom of the ratings were partly attributed to its continuing coverage of the NFL. With television contract re-negotiations in early 1998 ushering in the era of multibillion-dollar broadcasting agreements, an era of pro football broadcasting was about to end. CBS, stung by Fox's surprise bid four years earlier, aggressively sought to reacquire some broadcasting rights. CBS agreed to pay $4 billion over eight years ($500 million per season) to air AFC games.

NBC, meanwhile, had indicated a desire to bid for "Monday Night Football" rights in 1998, but gave up when the financial stakes increased sharply. Thus, after six decades, NBC, the network that had shaped television broadcasts of football, lost its rights, thus marking the beginning of a slow decline for its sports division, culminating in the unproductive 2004–05 prime time season, when NBC carried no major sporting championships during prime time (NBC had already lost Major League Baseball broadcasting rights in 2000 and National Basketball Association rights in 2002; they had acquired National Hockey League rights in 2004, but that league was in lockout, and furthermore, it was the least popular of the major leagues at the time).

NBC's attempts to replace the NFL with other professional football, including the XFL in 2001 and the Arena Football League coverage from 2003 to 2006, proved to be very unsuccessful. Like CBS before it, NBC would later decide that not having NFL rights did too much damage to its overall ratings to justify foregoing the high rights fees required.

The other networks also signed eight-year deals in 1998. Fox extended its NFC deal by agreeing to a $4.4 billion contract ($550 million per season). ABC retained its longtime rights to "Monday Night Football" by also paying $4.4 billion over eight years. ESPN agreed to a $4.8 billion ($600 million a season) deal to become the sole cable broadcaster of NFL games, marking an end to the league's association with TNT. As with previous TV contracts, the coverage of the Super Bowl was divided between the broadcast networks.

In 2002, the NFL began scheduling a Thursday night special opening "Kickoff" game, taking place on the Thursday after Labor Day leading into the opening Sunday slate of NFL games. The event includes a pre-game concert and other televised festivities. The first series of these events were held in New York and Washington, D.C., respectively, to celebrate both cities' resilience in the wake of the September 11, 2001 attacks. The 2002 San Francisco 49ers and the New York Giants game was held on September 5 and televised on ESPN. The 2003 edition featured the Washington Redskins hosting the New York Jets on September 4, 2003, and the game was televised by ABC. Since 2006, NBC has televised the Kickoff game ("see below").

Starting in 2004, the NFL began awarding the opening game to the defending Super Bowl champions as the official start of their title defense. The unfurling of the team's Super Bowl championship banner in their stadium has become a centerpiece of the opening ceremonies.

In 2012, the kickoff game between the New York Giants and Dallas Cowboys aired on Wednesday, September 5, to avoid conflict with the final night of the Democratic National Convention in which incumbent president Barack Obama delivered his acceptance speech for the party nomination.

In 2013, there was a change in the format. The Baltimore Ravens still played in the kickoff game, however, due to a scheduling and parking conflict with the Baltimore Orioles; the Ravens opened on the road against the Denver Broncos.

Recently, the NFL's TV broadcasters have suffered annual financial losses because advertising revenue is unable to keep up with the rising costs of broadcast rights.

Nevertheless, the current broadcast contract, which began in 2006, resulted in a sizable increase in total rights fees. Both Fox and CBS renewed their Sunday afternoon broadcast packages through 2011, in both cases with modest increases. Furthermore, the league and DirecTV signed a five-year extension to their exclusivity deal on NFL Sunday Ticket.

Despite relatively high, if declining, TV ratings, ABC decided to end its relationship with the NFL after losing significant money on "Monday Night Football". In addition to the fees, part of this decision may have been the result of a resurgent ABC prime time entertainment schedule during the 2004–05 season, particularly on Sunday evening with "Desperate Housewives"; thus ABC would be unable to satisfy the league's reported preference for a Sunday night game on broadcast television as opposed to Monday.

Because of that, "Monday Night Football" moved from ABC to ESPN, which are both owned by The Walt Disney Company. The cable network paid $1.1 billion per year from 2006 to 2014 for the rights. Unlike the broadcast networks, however, ESPN can generate revenue from subscription sales, in addition to traditional commercial breaks (ESPN's subscriber fees are the highest of any American cable network, more than four times that of second-place TNT). The cable network's coverage begins at 1:00 p.m. ET with "SportsCenter Special Edition: Monday Night Kickoff". The 2009 edition saw the game itself start at 8:30 p.m., with Mike Tirico, Ron Jaworski, and Jon Gruden in the broadcast booths.

Meanwhile, NBC, after losing the AFC package to CBS in 1997, was able to reclaim some broadcast rights with a deal worth an average of $650 million per year to air the Sunday night package from 2006 to 2014 (not much more than what ESPN used to pay for the same rights). This new deal included the Super Bowl in 2009 and 2012.

NBC's coverage also includes two preseason games (including the annual Hall of Fame Game), the first two Wild Card playoff games of each post-season, and the annual Thursday opening Kickoff Game, similar to ABC's broadcast rights package. The major difference was that the NFL allowed NBC flexibility in selecting games in the latter part of the season. ABC did not have the right to be flexible with their "Monday Night Football" schedule and picked matchups based on a team's record in the previous season (as NBC does), which often led to teams with losing records playing each other on Monday night later in the season.

The moves were intended to break NBC out of its ratings slump; however, at one point in the last decade, this did not happen, and although "NBC Sunday Night Football" had been (and continues to be) the network's top rated program and in the top 30 for viewing audience, it had not lifted the rest of the schedule. For a time, NBC had been firmly in fourth place and was losing large sums of money, so much so that the network had to cut an hour of prime time programming from its weeknight schedule in favor of "The Jay Leno Show", a somewhat lower budget talk show which lasted five months. The network has since slowly come back to second place in the network ratings.

Coverage of "NBC Sunday Night Football" starts at 8:15 p.m. ET with Al Michaels serving as the play-by-play announcer, Cris Collinsworth as color commentator, and Michele Tafoya as the sole sideline reporter. Each telecast begins with a pre-game show airing at 7 p.m. ET entitled "Football Night in America", hosted by Bob Costas.

In addition, for the first three years of the contract, the network that carried the Super Bowl also broadcast the Pro Bowl on the Saturday night following the championship game. In 2007, CBS broadcast both games, followed by Fox in 2008, and NBC in 2009. In 2010, the Pro Bowl was played the weekend before the Super Bowl, broadcast by ESPN. The 2010 deal was meant as a one-time situation to protect the Winter Olympics in Vancouver that started the next week (as well as the NBA All-Star Game and the Daytona 500), but the NFL played the 2011 and 2012 games in Honolulu the week before the Super Bowl.

The NFL Network was created by the league in 2003 and given a separate package of broadcast games. The eight-game package consisted of prime time games which in 2006 and 2007 began airing from Thanksgiving to the end of the regular season. Five games aired on Thursday nights and three on Saturday nights, the latter beginning Week 15 of the season. Starting in the 2008 season the ratio and dates of the games changed: now there are seven Thursday night games beginning in the first week of November and continuing to Week 16. There is only one Saturday night game, airing during Week 15 or 16 (usually 16, but when Saturday is Christmas Eve, it airs in week 15). The NFL could theoretically decide to sell this package to another network should NFL Network broadcasts not generate enough revenue. NFL Network will also carry several preseason games. The introduction of the NFL Network games also marked the end to late-season Saturday afternoon regular season games on the networks that aired Sunday afternoon games: CBS, Fox and NBC.

ESPN renewed its contract with the NFL in 2011 which extends to ESPN the NFL broadcast rights through the 2021-22 season. ESPN increased the purchase price for the eighteen-game package, which will include in 2015 the Pro Bowl. Cable television operators condemned the contract, noting that ESPN has the highest retransmission consent fees of any national cable television channel, nearly five times higher than the nearest competitor (TNT), and raises fees on an annual basis. Nevertheless, the other networks had intended to follow suit by renewing their contracts through 2021-22, increasing their price to over $1 billion per year. The remaining networks announced they had indeed renewed with the NFL on December 14, 2011. Both the new ESPN and broadcast deals take effect in 2014-15 and will continue through Super Bowl LVI in 2022.

As for the rest of the changes, they consist of the following:In addition to that, all of the networks were afforded the rights to stream games on the Internet via the TV Everywhere initiative, but not to mobile devices (as Verizon Wireless, through its NFL Mobile app, maintained exclusive rights to all devices or smaller through the 2017 season); the streaming rights are effective immediately, as NBC and Verizon both carried Super Bowl XLVI online for the first time ever. NBC is paying an average annual rights fee of $950 million for its broadcast rights; CBS $1 billion, and Fox $1.1 billion; the actual amount is slightly lower at the beginning of the contract and higher at the end to compensate for inflation.

On February 5, 2014, the league announced it had sold off eight weeks of the NFL Network's "Thursday Night Football" package to CBS, who outbid competitors ABC, Fox, NBC, and Turner Sports. NFL Network will simulcast CBS' Thursday night games from weeks 2 through 8, will continue to carry the Thursday night games from Week 9 onward, and will also carry two Saturday night games (Week 16 doubleheader) for the first time since 2011, with one of those games being simulcast on CBS. All of these games (except for the one NFL Network-only Saturday night game) will be announced by CBS' lead commentating team of Jim Nantz (play-by-play) and Phil Simms (color analyst). The deal with CBS was initially only for the 2014 season, with the league having the option to extend it for an additional season. CBS is paying an additional $275 million for the package. Local CBS affiliates automatically get the local simulcast rights to any game carried only on NFL Network. The league exercised the option to extend its agreement with CBS through the 2015 season. For 2016 and 2017, the league split a ten-game package of Thursday night games between NBC and CBS, with each paying an estimated $225 million per season for five games; CBS's games will be in the early part of the season as before, while NBC's will cover later in the season. Under the terms of NFL Network's retransmission agreements with cable providers, the NFL has included a stipulation requiring seven games in the "Thursday Night Football" package to be carried solely on NFL Network; for the 2018 season, potential bidders were free to place a bid on a package ranging from anywhere between four and eleven games. Fox, the winning bidder, bought all eleven games that were up for bids. As the eighteen total games involve more time slots than can be accommodated with the fourteen Thursday night time slots (excluding the kickoff, Thanksgiving, and the last week of the season when no Thursday game is played), four of the games are played on days other than Thursdays (usually this involves at least one game in London in a Sunday morning time slot and the remainder on Saturdays, all NFL Network exclusives), or if Christmas lands on a Monday, either a Christmas Eve or Christmas Day game.

Verizon has held rights to carry video simulcasts of NFL games to devices or less since such simulcasts have been viable. The company initially made these telecasts available only to its own wireless service subscribers, even going so far as to block the networks from providing their own feeds to those devices. Beginning in 2018, at the league's behest, it broadened the availability to all devices of that size and offered them through a newly acquired subsidiary, Yahoo! Sports. (Yahoo! has twice carried exclusive NFL games, both based in London, which were available to larger devices as well.) At the same time, Verizon dropped its prohibition on the networks offering the feeds to small devices. Verizon's NFL feeds are limited to Sunday and Monday nights, plus the locally telecast game in the phone's location (determined by the phone's GPS locator); Verizon offers Thursday night games but will only stream those games over a mobile data connection, whereas other games streamed through Verizon can use wi-fi.

The "Thursday Night Football" contract, uniquely among the league's television packages, has a separate digital contract allowing games to be carried freely to all Internet devices since 2016. Twitter carried the 2016 season before being outbid in 2017 by Amazon, who has held the rights since. For the 2017 season it required an Amazon Prime subscription to access the streams; it began offering the streams freely through its gaming-centric streaming service Twitch.tv in 2018.


Who discovered the quark?

The first strange particle (a particle containing a strange quark) was discovered in 1947 (kaons), but the existence of the strange quark itself (and that of the up and down quarks) was only postulated in 1964 by Murray Gell-Mann and George Zweig to explain the Eightfold Way classification scheme of hadrons. The first evidence for the existence of quarks came in 1968, in deep inelastic scattering experiments at the Stanford Linear Accelerator Center. These experiments confirmed the existence of up and down quarks, and by extension, strange quarks, as they were required to explain the Eightfold Way.

Strange quark

The strange quark or s quark (from its symbol, s) is the third lightest of all quarks, a type of elementary particle. Strange quarks are found in subatomic particles called hadrons. Example of hadrons containing strange quarks include kaons (), strange D mesons (), Sigma baryons (), and other strange particles.

According to the IUPAP the symbol s is the official name, while strange is to be considered only as a mnemonic. The name sideways has also been used because the s quark has a I value of 0 while the u (“up”) and d (“down”) quarks have values of + and − respectively.

Along with the charm quark, it is part of the second generation of matter, and has an electric charge of − "e" and a bare mass of. Like all quarks, the strange quark is an elementary fermion with spin, and experiences all four fundamental interactions: gravitation, electromagnetism, weak interactions, and strong interactions. The antiparticle of the strange quark is the strange antiquark (sometimes called "antistrange quark" or simply "antistrange"), which differs from it only in that some of its properties have equal magnitude but opposite sign.

In the beginnings of particle physics (first half of the 20th century), hadrons such as protons, neutrons and pions were thought to be elementary particles. However, new hadrons were discovered and the 'particle zoo' grew from a few particles in the early 1930s and 1940s to several dozens of them in the 1950s. Some particles were much longer lived than others; most particles decayed through the strong interaction and had lifetimes of around 10 seconds. When they decayed through the weak interactions, they had lifetimes of around 10 seconds. While studying these decays, Murray Gell-Mann (in 1953) and Kazuhiko Nishijima (in 1955) developed the concept of "strangeness" (which Nishijima called "eta-charge", after the eta meson ()) to explain the'strangeness' of the longer-lived particles. The Gell-Mann–Nishijima formula is the result of these efforts to understand strange decays.

Despite their work, the relationships between each particle and the physical basis behind the strangeness property remained unclear. In 1961, Gell-Mann and Yuval Ne'eman independently proposed a hadron classification scheme called the Eightfold Way, also known as SU(3) flavor symmetry. This ordered hadrons into isospin multiplets. The physical basis behind both isospin and strangeness was only explained in 1964, when Gell-Mann and George Zweig independently proposed the quark model, which at that time consisted only of the up, down, and strange quarks. Up and down quarks were the carriers of isospin, while the strange quark carried strangeness. While the quark model explained the Eightfold Way, no direct evidence of the existence of quarks was found until 1968 at the Stanford Linear Accelerator Center. Deep inelastic scattering experiments indicated that protons had substructure, and that protons made of three more-fundamental particles explained the data (thus confirming the quark model).

At first people were reluctant to identify the three-bodies as quarks, instead preferring Richard Feynman's parton description, but over time the quark theory became accepted (see "November Revolution").

The quark model was independently proposed by physicists Murray Gell-Mann and George Zweig in 1964. Quarks were introduced as parts of an ordering scheme for hadrons, and there was little evidence for their physical existence until deep inelastic scattering experiments at the Stanford Linear Accelerator Center in 1968. Accelerator experiments have provided evidence for all six flavors. The top quark, first observed at Fermilab in 1995, was the last to be discovered.

Quark

A quark () is a type of elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons, the components of atomic nuclei. Due to a phenomenon known as "color confinement", quarks are never directly observed or found in isolation; they can be found only within hadrons, which include baryons (such as protons and neutrons) and mesons. For this reason, much of what is known about quarks has been drawn from observations of hadrons.

Quarks have various intrinsic properties, including electric charge, mass, color charge, and spin. They are the only elementary particles in the Standard Model of particle physics to experience all four fundamental interactions, also known as "fundamental forces" (electromagnetism, gravitation, strong interaction, and weak interaction), as well as the only known particles whose electric charges are not integer multiples of the elementary charge.

There are six types, known as "flavors", of quarks: up, down, strange, charm, bottom, and top. Up and down quarks have the lowest masses of all quarks. The heavier quarks rapidly change into up and down quarks through a process of particle decay: the transformation from a higher mass state to a lower mass state. Because of this, up and down quarks are generally stable and the most common in the universe, whereas strange, charm, bottom, and top quarks can only be produced in high energy collisions (such as those involving cosmic rays and in particle accelerators). For every quark flavor there is a corresponding type of antiparticle, known as an antiquark, that differs from the quark only in that some of its properties (such as the electric charge) have equal magnitude but opposite sign.

The Standard Model is the theoretical framework describing all the currently known elementary particles. This model contains six flavors of quarks (), named up (), down (), strange (), charm (), bottom (), and top (). Antiparticles of quarks are called "antiquarks", and are denoted by a bar over the symbol for the corresponding quark, such as for an up antiquark. As with antimatter in general, antiquarks have the same mass, mean lifetime, and spin as their respective quarks, but the electric charge and other charges have the opposite sign.

Quarks are spin- particles, implying that they are fermions according to the spin–statistics theorem. They are subject to the Pauli exclusion principle, which states that no two identical fermions can simultaneously occupy the same quantum state. This is in contrast to bosons (particles with integer spin), of which any number can be in the same state. Unlike leptons, quarks possess color charge, which causes them to engage in the strong interaction. The resulting attraction between different quarks causes the formation of composite particles known as "hadrons" (see "Strong interaction and color charge" below).

The quarks that determine the quantum numbers of hadrons are called "valence quarks"; apart from these, any hadron may contain an indefinite number of virtual "sea" quarks, antiquarks, and gluons, which do not influence its quantum numbers. There are two families of hadrons: baryons, with three valence quarks, and mesons, with a valence quark and an antiquark. The most common baryons are the proton and the neutron, the building blocks of the atomic nucleus. A great number of hadrons are known (see list of baryons and list of mesons), most of them differentiated by their quark content and the properties these constituent quarks confer. The existence of "exotic" hadrons with more valence quarks, such as tetraquarks () and pentaquarks (), was conjectured from the beginnings of the quark model but not discovered until the early 21st century.

Elementary fermions are grouped into three generations, each comprising two leptons and two quarks. The first generation includes up and down quarks, the second strange and charm quarks, and the third bottom and top quarks. All searches for a fourth generation of quarks and other elementary fermions have failed, and there is strong indirect evidence that no more than three generations exist. Particles in higher generations generally have greater mass and less stability, causing them to decay into lower-generation particles by means of weak interactions. Only first-generation (up and down) quarks occur commonly in nature. Heavier quarks can only be created in high-energy collisions (such as in those involving cosmic rays), and decay quickly; however, they are thought to have been present during the first fractions of a second after the Big Bang, when the universe was in an extremely hot and dense phase (the quark epoch). Studies of heavier quarks are conducted in artificially created conditions, such as in particle accelerators.

Having electric charge, mass, color charge, and flavor, quarks are the only known elementary particles that engage in all four fundamental interactions of contemporary physics: electromagnetism, gravitation, strong interaction, and weak interaction. Gravitation is too weak to be relevant to individual particle interactions except at extremes of energy (Planck energy) and distance scales (Planck distance). However, since no successful quantum theory of gravity exists, gravitation is not described by the Standard Model.

See the table of properties below for a more complete overview of the six quark flavors' properties.

The quark model was independently proposed by physicists Murray Gell-Mann and George Zweig in 1964. The proposal came shortly after Gell-Mann's 1961 formulation of a particle classification system known as the "Eightfold Way"—or, in more technical terms, SU(3) flavor symmetry, streamlining its structure. Physicist Yuval Ne'eman had independently developed a scheme similar to the Eightfold Way in the same year. An early attempt at constituent organization was available in the Sakata model.

At the time of the quark theory's inception, the "particle zoo" included, amongst other particles, a multitude of hadrons. Gell-Mann and Zweig posited that they were not elementary particles, but were instead composed of combinations of quarks and antiquarks. Their model involved three flavors of quarks, up, down, and strange, to which they ascribed properties such as spin and electric charge. The initial reaction of the physics community to the proposal was mixed. There was particular contention about whether the quark was a physical entity or a mere abstraction used to explain concepts that were not fully understood at the time.

In less than a year, extensions to the Gell-Mann–Zweig model were proposed. Sheldon Lee Glashow and James Bjorken predicted the existence of a fourth flavor of quark, which they called "charm". The addition was proposed because it allowed for a better description of the weak interaction (the mechanism that allows quarks to decay), equalized the number of known quarks with the number of known leptons, and implied a mass formula that correctly reproduced the masses of the known mesons.

In 1968, deep inelastic scattering experiments at the Stanford Linear Accelerator Center (SLAC) showed that the proton contained much smaller, point-like objects and was therefore not an elementary particle. Physicists were reluctant to firmly identify these objects with quarks at the time, instead calling them "partons"—a term coined by Richard Feynman. The objects that were observed at SLAC would later be identified as up and down quarks as the other flavors were discovered. Nevertheless, "parton" remains in use as a collective term for the constituents of hadrons (quarks, antiquarks, and gluons).

The strange quark's existence was indirectly validated by SLAC's scattering experiments: not only was it a necessary component of Gell-Mann and Zweig's three-quark model, but it provided an explanation for the kaon () and pion () hadrons discovered in cosmic rays in 1947.

In a 1970 paper, Glashow, John Iliopoulos and Luciano Maiani presented the so-called GIM mechanism to explain the experimental non-observation of flavor-changing neutral currents. This theoretical model required the existence of the as-yet undiscovered charm quark. The number of supposed quark flavors grew to the current six in 1973, when Makoto Kobayashi and Toshihide Maskawa noted that the experimental observation of CP violation could be explained if there were another pair of quarks.

Charm quarks were produced almost simultaneously by two teams in November 1974 (see November Revolution)—one at SLAC under Burton Richter, and one at Brookhaven National Laboratory under Samuel Ting. The charm quarks were observed bound with charm antiquarks in mesons. The two parties had assigned the discovered meson two different symbols, and ; thus, it became formally known as the meson. The discovery finally convinced the physics community of the quark model's validity.

In the following years a number of suggestions appeared for extending the quark model to six quarks. Of these, the 1975 paper by Haim Harari was the first to coin the terms "top" and "bottom" for the additional quarks.

In 1977, the bottom quark was observed by a team at Fermilab led by Leon Lederman. This was a strong indicator of the top quark's existence: without the top quark, the bottom quark would have been without a partner. However, it was not until 1995 that the top quark was finally observed, also by the CDF and DØ teams at Fermilab. It had a mass much larger than had been previously expected, almost as large as that of a gold atom.
For some time, Gell-Mann was undecided on an actual spelling for the term he intended to coin, until he found the word "quark" in James Joyce's book "Finnegans Wake":
The word "quark" itself is a Slavic borrowing in German and denotes a dairy product, but is also a colloquial term for ″rubbish″. Gell-Mann went into further detail regarding the name of the quark in his book "The Quark and the Jaguar":
Zweig preferred the name "ace" for the particle he had theorized, but Gell-Mann's terminology came to prominence once the quark model had been commonly accepted.

The quark flavors were given their names for several reasons. The up and down quarks are named after the up and down components of isospin, which they carry. Strange quarks were given their name because they were discovered to be components of the strange particles discovered in cosmic rays years before the quark model was proposed; these particles were deemed "strange" because they had unusually long lifetimes. Glashow, who co-proposed charm quark with Bjorken, is quoted as saying, "We called our construct the 'charmed quark', for we were fascinated and pleased by the symmetry it brought to the subnuclear world." The names "bottom" and "top", coined by Harari, were chosen because they are "logical partners for up and down quarks". In the past, bottom and top quarks were sometimes referred to as "beauty" and "truth" respectively, but these names have somewhat fallen out of use. While "truth" never did catch on, accelerator complexes devoted to massive production of bottom quarks are sometimes called "beauty factories".

Quarks have fractional electric charge values – either (−) or (+) times the elementary charge (e), depending on flavor. Up, charm, and top quarks (collectively referred to as "up-type quarks") have a charge of + e, while down, strange, and bottom quarks ("down-type quarks") have − e. Antiquarks have the opposite charge to their corresponding quarks; up-type antiquarks have charges of − e and down-type antiquarks have charges of + e. Since the electric charge of a hadron is the sum of the charges of the constituent quarks, all hadrons have integer charges: the combination of three quarks (baryons), three antiquarks (antibaryons), or a quark and an antiquark (mesons) always results in integer charges. For example, the hadron constituents of atomic nuclei, neutrons and protons, have charges of 0 e and +1 e respectively; the neutron is composed of two down quarks and one up quark, and the proton of two up quarks and one down quark.

Spin is an intrinsic property of elementary particles, and its direction is an important degree of freedom. It is sometimes visualized as the rotation of an object around its own axis (hence the name ""), though this notion is somewhat misguided at subatomic scales because elementary particles are believed to be point-like.

Spin can be represented by a vector whose length is measured in units of the reduced Planck constant "ħ" (pronounced "h bar"). For quarks, a measurement of the spin vector component along any axis can only yield the values +"ħ"/2 or −"ħ"/2; for this reason quarks are classified as spin- particles. The component of spin along a given axis – by convention the "z" axis – is often denoted by an up arrow ↑ for the value + and down arrow ↓ for the value −, placed after the symbol for flavor. For example, an up quark with a spin of + along the "z" axis is denoted by u↑.

A quark of one flavor can transform into a quark of another flavor only through the weak interaction, one of the four fundamental interactions in particle physics. By absorbing or emitting a W boson, any up-type quark (up, charm, and top quarks) can change into any down-type quark (down, strange, and bottom quarks) and vice versa. This flavor transformation mechanism causes the radioactive process of beta decay, in which a neutron () "splits" into a proton (), an electron () and an electron antineutrino () (see picture). This occurs when one of the down quarks in the neutron () decays into an up quark by emitting a virtual boson, transforming the neutron into a proton (). The boson then decays into an electron and an electron antineutrino.

Both beta decay and the inverse process of "inverse beta decay" are routinely used in medical applications such as positron emission tomography (PET) and in experiments involving neutrino detection.
While the process of flavor transformation is the same for all quarks, each quark has a preference to transform into the quark of its own generation. The relative tendencies of all flavor transformations are described by a mathematical table, called the Cabibbo–Kobayashi–Maskawa matrix (CKM matrix). Enforcing unitarity, the approximate magnitudes of the entries of the CKM matrix are:
where "V" represents the tendency of a quark of flavor "i" to change into a quark of flavor "j" (or vice versa).

There exists an equivalent weak interaction matrix for leptons (right side of the W boson on the above beta decay diagram), called the Pontecorvo–Maki–Nakagawa–Sakata matrix (PMNS matrix). Together, the CKM and PMNS matrices describe all flavor transformations, but the links between the two are not yet clear.

According to quantum chromodynamics (QCD), quarks possess a property called "color charge". There are three types of color charge, arbitrarily labeled "blue", "green", and "red". Each of them is complemented by an anticolor – "antiblue", "antigreen", and "antired". Every quark carries a color, while every antiquark carries an anticolor.

The system of attraction and repulsion between quarks charged with different combinations of the three colors is called strong interaction, which is mediated by force carrying particles known as "gluons"; this is discussed at length below. The theory that describes strong interactions is called quantum chromodynamics (QCD). A quark, which will have a single color value, can form a bound system with an antiquark carrying the corresponding anticolor. The result of two attracting quarks will be color neutrality: a quark with color charge "ξ" plus an antiquark with color charge −"ξ" will result in a color charge of 0 (or "white" color) and the formation of a meson. This is analogous to the additive color model in basic optics. Similarly, the combination of three quarks, each with different color charges, or three antiquarks, each with anticolor charges, will result in the same "white" color charge and the formation of a baryon or antibaryon.

In modern particle physics, gauge symmetries – a kind of symmetry group – relate interactions between particles (see gauge theories). Color SU(3) (commonly abbreviated to SU(3)) is the gauge symmetry that relates the color charge in quarks and is the defining symmetry for quantum chromodynamics. Just as the laws of physics are independent of which directions in space are designated "x", "y", and "z", and remain unchanged if the coordinate axes are rotated to a new orientation, the physics of quantum chromodynamics is independent of which directions in three-dimensional color space are identified as blue, red, and green. SU(3) color transformations correspond to "rotations" in color space (which, mathematically speaking, is a complex space). Every quark flavor "f", each with subtypes "f", "f", "f" corresponding to the quark colors, forms a triplet: a three-component quantum field which transforms under the fundamental representation of SU(3). The requirement that SU(3) should be local – that is, that its transformations be allowed to vary with space and time – determines the properties of the strong interaction. In particular, it implies the existence of eight gluon types to act as its force carriers.

Two terms are used in referring to a quark's mass: "current quark mass" refers to the mass of a quark by itself, while "constituent quark mass" refers to the current quark mass plus the mass of the gluon particle field surrounding the quark. These masses typically have very different values. Most of a hadron's mass comes from the gluons that bind the constituent quarks together, rather than from the quarks themselves. While gluons are inherently massless, they possess energy – more specifically, quantum chromodynamics binding energy (QCBE) – and it is this that contributes so greatly to the overall mass of the hadron (see mass in special relativity). For example, a proton has a mass of approximately 938 MeV/c, of which the rest mass of its three valence quarks only contributes about 9 MeV/c; much of the remainder can be attributed to the field energy of the gluons. See Chiral symmetry breaking.
The Standard Model posits that elementary particles derive their masses from the Higgs mechanism, which is associated to the Higgs boson. It is hoped that further research into the reasons for the top quark's large mass of ~173 GeV/c, almost the mass of a gold atom, might reveal more about the origin of the mass of quarks and other elementary particles.

In QCD, quarks are considered to be point-like entities, with zero size. As of 2014, experimental evidence indicates they are no bigger than 10 times the size of a proton, i.e. less than 10 metres.

The following table summarizes the key properties of the six quarks. Flavor quantum numbers (isospin ("I"), charm ("C"), strangeness ("S", not to be confused with spin), topness ("T"), and bottomness ("B"′)) are assigned to certain quark flavors, and denote qualities of quark-based systems and hadrons. The baryon number ("B") is + for all quarks, as baryons are made of three quarks. For antiquarks, the electric charge ("Q") and all flavor quantum numbers ("B", "I", "C", "S", "T", and "B"′) are of opposite sign. Mass and total angular momentum ("J"; equal to spin for point particles) do not change sign for the antiquarks.

As described by quantum chromodynamics, the strong interaction between quarks is mediated by gluons, massless vector gauge bosons. Each gluon carries one color charge and one anticolor charge. In the standard framework of particle interactions (part of a more general formulation known as perturbation theory), gluons are constantly exchanged between quarks through a virtual emission and absorption process. When a gluon is transferred between quarks, a color change occurs in both; for example, if a red quark emits a red–antigreen gluon, it becomes green, and if a green quark absorbs a red–antigreen gluon, it becomes red. Therefore, while each quark's color constantly changes, their strong interaction is preserved.

Since gluons carry color charge, they themselves are able to emit and absorb other gluons. This causes "asymptotic freedom": as quarks come closer to each other, the chromodynamic binding force between them weakens. Conversely, as the distance between quarks increases, the binding force strengthens. The color field becomes stressed, much as an elastic band is stressed when stretched, and more gluons of appropriate color are spontaneously created to strengthen the field. Above a certain energy threshold, pairs of quarks and antiquarks are created. These pairs bind with the quarks being separated, causing new hadrons to form. This phenomenon is known as "color confinement": quarks never appear in isolation. This process of hadronization occurs before quarks, formed in a high energy collision, are able to interact in any other way. The only exception is the top quark, which may decay before it hadronizes.

Hadrons contain, along with the "valence quarks" () that contribute to their quantum numbers, virtual quark–antiquark () pairs known as "sea quarks" (). Sea quarks form when a gluon of the hadron's color field splits; this process also works in reverse in that the annihilation of two sea quarks produces a gluon. The result is a constant flux of gluon splits and creations colloquially known as "the sea". Sea quarks are much less stable than their valence counterparts, and they typically annihilate each other within the interior of the hadron. Despite this, sea quarks can hadronize into baryonic or mesonic particles under certain circumstances.

Under sufficiently extreme conditions, quarks may become deconfined and exist as free particles. In the course of asymptotic freedom, the strong interaction becomes weaker at higher temperatures. Eventually, color confinement would be lost and an extremely hot plasma of freely moving quarks and gluons would be formed. This theoretical phase of matter is called quark–gluon plasma. The exact conditions needed to give rise to this state are unknown and have been the subject of a great deal of speculation and experimentation. A recent estimate puts the needed temperature at kelvin. While a state of entirely free quarks and gluons has never been achieved (despite numerous attempts by CERN in the 1980s and 1990s), recent experiments at the Relativistic Heavy Ion Collider have yielded evidence for liquid-like quark matter exhibiting "nearly perfect" fluid motion.

The quark–gluon plasma would be characterized by a great increase in the number of heavier quark pairs in relation to the number of up and down quark pairs. It is believed that in the period prior to 10 seconds after the Big Bang (the quark epoch), the universe was filled with quark–gluon plasma, as the temperature was too high for hadrons to be stable.

Given sufficiently high baryon densities and relatively low temperatures – possibly comparable to those found in neutron stars – quark matter is expected to degenerate into a Fermi liquid of weakly interacting quarks. This liquid would be characterized by a condensation of colored quark Cooper pairs, thereby breaking the local SU(3) symmetry. Because quark Cooper pairs harbor color charge, such a phase of quark matter would be color superconductive; that is, color charge would be able to pass through it with no resistance.