Sports

in the USA are:
football (outside the USA known as American football);
basketball;
baseball;
ice hockey.

school and college athletes.
In Texas it is compared to a religion.
It manifests playing through pain and sacrificing for the better of the team.
Became rather popular outside the US, e.g. in Japan.

National Football League is a major professional football league in US.
It was founded on August 20th, 1920.
Contains 32 teams.
Most recent champion: Seattle Seahawks

more than 300 million people worldwide in an organized fashion.
Games might often have unpredictable finishes, that’s why it’s so popular.

National Basketball Association is a major professional basketball league in US.
It was founded on June 6th, 1946.
Contains 30 teams.
Most recent champion: San Antonio Spurs

baseball in US was in 1791 in Pittsfield, MA.
Baseball is played around the world, too.

Major League Baseball is a major professional baseball league in US.
It was founded in 1869. Contains 30 teams.
Most recent champion: San Francisco Giants

its popularity is lower than that of sports originated in US.
The Stanley Cup is the oldest sports trophy in the world.
Excellent performance of skaters and goaltenders, fast speeds and fights make hockey one the most spectacular games in the world.

National Hockey League is a major professional hockey league in US.
It was founded on November 26th , 1917 in Montreal, QC, Canada.
Contains 30 teams (7 from Canada, 23 from US).
Most recent champion: Los Angeles Kings

This pressure of competition is felt by players, coaches, and management, but is felt strongest by the fans.

Celtics–76ers rivalry (NBA).

and television ratings.
A rivalry that gets out of control can lead to fighting, hooliganism, rioting, etc.
Often the topic of sports rivalries is as heated and controversial as politics and religion.

Penguins–Flyers rivalry (NHL).