Under a new proposal by Major League Baseball, pitchers would be required to finish their warm-up pitches and be ready to make their first pitch of an inning 30 seconds before the end of all between-inning commercial breaks, according to sources.

Hitters would have to be in the batter's box, ready to start their at-bats, 20 seconds before the end of each break.

Both proposals are designed to decrease the time between half-innings, which has grown, on average, to more than three minutes, even though regular-season commercial breaks during games that are not nationally televised are supposed to last just 2 minutes, 5 seconds.

Baseball officials believe that if play is ready to resume moments after each break ends, they could shorten games by 10 to 15 minutes.