An average TV hour is 36 percent commercials [source: Marketing Charts]. This includes commercials bookending the show and two commercial breaks during the action. Coincidentally, this almost exactly matches the pace of baseball, in which commercials come every three outs, plus pitching changes, plus the seventh-inning stretch.
And who can deny the inherent appeal of the pitcher-versus-batter close-up? It's as if baseball players were made for the camera, posing just long enough for a long lens to capture the droplets of sweat dripping from a pitcher's nose -- as much cowboy movie as it is sporting event.
Football does all right, too, due to the rhythm of punts and timeouts. Basketball is just a bit trickier, but fouls and quarters break up the game enough to ensure ample ad time. When in doubt, use the TV timeout!
But not so much for soccer and hockey. How is a beer advertiser supposed to work with 45 minutes plus injury time of continuous action, followed by a halftime break during which the audience is almost certainly away from the screen? Add to that the fact that you can't see the darn puck in hockey and the fact that the ball tends to be passed off in any direction in soccer (negating the potential for the all-important close-ups), and you have the rise of telegenic sports and the demise of the rest.