All 30 Major League Baseball teams have unanimously approved an expanded instant replay system that will take effect starting with the 2014 season. Managers will now have "at least one" chance each game to have nearly any on-field call reviewed via instant replay. When a challenge is issued, MLB umpires working at the "Replay Command Center" in New York will review the play in question and make the final decision on overturning any call. Once a game enters the seventh inning, its umpire crew chief can choose to invoke instant replay on any reviewable call.

All 30 MLB ballparks will install a hard-wired headset near home plate where umpires at each game can communicate with the Command Center. As part of the new rules, teams will also be permitted to show any replay they'd like on the ballpark scoreboard — even those that aren't being reviewed. The new system will be tested during Spring Training to ensure that all clubs are ready for the regular season.

"I am very pleased that instant replay will expand to include additional impactful plays," said MLB commissioner Bud Selig. "The new system will give managers valuable recourse in potentially game-changing situations." Notably, replays cannot be used to argue an umpire's strike zone, ensuring that the so-called "human element" will still play a key role in America's pastime. Major League Baseball has other tools at its disposal to track umpire accuracy in that department. The specifics of the new rules are as follows:

Managers will have at least one challenge to use. If any portion of a challenged play is overturned, then the manager who challenged the play will retain the ability to challenge one more play during the game. No manager may challenge more than two plays in a game. Once the manager has exhausted his ability to challenge plays during the game and after the beginning of the seventh inning, the Crew Chief may choose to invoke instant replay on any reviewable call. Home run and other boundary calls will remain reviewable under the procedures in place last season.