Major League Baseball will institute a limited use of instant replay to decide whether or not a potential home run is fair or foul or if a fan interfered or even if the ball actually went out of the park, starting on Thursday.
All games will be monitored and staffed by an expert technician and either an umpire supervisor or a former umpire at Major League Baseball Advanced Media (MLB.com) headquarters in New York.
A television monitor and a secure telephone link to MLB.com, placed next to the monitor, have been installed during the past few weeks at every Major League ballpark. The positions vary. Some are located in dugouts and others are near the umpires' dressing quarters.
If the crew chief determines that instant replay review is necessary on a particular disputed home run, then he will call the MLB.com technician, who will transmit the most appropriate video footage to the crew chief and the umpire crew on site. The umpire supervisor or former umpire will not have direct communication with any of the umpires on site.
The decision to reverse a call will be at the sole discretion of the crew chief. The standard used by the crew chief when reviewing a play will be whether there is clear and convincing evidence that the umpire's decision on the field was incorrect and should be reversed.
Once instant replay review is invoked, whether or not the call has been reversed, neither club will be permitted to further argue the decision. A player, manager or coach who continues to argue will be treated in the same manner as one who argues balls and strikes and subject to ejection from the game.