Actually, the national anthem was not always played before every game. (For that matter, there wasn’t even a national anthem until Congress designated “The Star-Spangled Banner” as such in 1931.) It only became a routine patriotic flourish during World War II. Today, sports fans routinely talk, eat, and drink through it, but as long as they’re standing up, no one minds! The networks often make sure it’s played well before the game actually starts, to ensure that they don’t have to waste valuable advertising time broadcasting it.