• A review will be initiated when a manager informs the umpire that he wants to challenge a play. He will be allowed one challenge in the first six innings and two more from the seventh through the end of the game.This will keep sports talk radio stations in material for a generation.
• If the manager wins his appeal, he retains the challenge. The challenge from the first six innings does not carry over.
• Not all plays are reviewable.
• If a manager disagrees with a reviewable call, his only recourse would be to use a challenge. Managers would not be able to argue a reviewable call in a bid to get it overturned without the use of replay. A manager could still argue in situations not open to review, such as when defending a player or questioning an improper substitution.
• All replays will be reviewed by umpires at MLB.com headquarters in New York, with technicians available to provide the necessary video.
• However, boundary calls on home runs have been grandfathered. The on-site umpires will retain the right to submit the plays for review or not.
• There is no provision to cover the possibility of an obviously blown call late in the game if the manager has used all his challenges.