NBC can be accredited to the first television broadcast of a National Football League (NFL) game, when they covered a game on 22 October 1939 between the Philadelphia Eagles and the Brooklyn Dodgers. The broadcast rights of the NFL soon became an important property after the 1958 NFL Championship.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 into a primetime spectacle from an afternoon broadcast.
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 FA Premier League. This prevented the footage of any major Premiership 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 current contracts end in 2007. 
In the United States, sports are broadcast by networks usually only in "game of the week" or championship situations, except for the NFL (see NFL on television). 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 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.
Radio sports coverage is also important. The BBC's Radio Five 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. BBC Local Radio also provides extensive coverage of sport, giving more exposure to second-tier clubs which get limited national coverage.
In the United States, the cable channel ESPN is by far the largest dedicated sports channel. It has spawned ESPN2, and the two networks broadcast a wide variety of sporting events, ranging from major sports playoffs to lumberjack contests and poker.
ESPN has even been the namesake of several children as documented in this BBC article
Several regional sports channels offer lower-profile content. Examples include the many regional Fox Sports Networks.
CBS College Sports Network, ESPNU and Fox College Sports broadcast collegiate (university) sporting events with smaller audiences that have heretofore been largely absent from national television.
With the growing number of 'niche' channels on the U.S. television landscape, a swarm of channels have sprung up that focus heavily or exclusively on one sport:
Some of the world's largest sports clubs have their own channels, or own shares in other sports networks. Examples include Yankees Entertainment and Sports and Manchester United TV. An example of the latter, the Boston Red Sox own a majority stake of the regional New England Sports Network which retains the New England area television broadcast rights for the majority of Red Sox games (except for the few which are carried nationally on Fox or ESPN and playoff games) and Madison Square Garden which has its own network, where they broadcast original shows, New York Rangers, New York Knicks, and high school basketball games.