Who are the replay officials?
They will be full-time umpires. Major League Baseball essentially has hired two additional crews who will rotate through New York as part of their regular assignments. For example, a crew might work a series at Citi Field or Yankee Stadium, then a replay shift, then move on to Philadelphia or Boston.
How will umpires decide whether to review calls after the sixth inning?
Each manager starts the game with one challenge. If he uses it and the call is overturned, he gets one more but can never have more than two. If he still has a challenge after the sixth, he must use it if he wants to challenge a call.
However, if a manager is out of challenges, he may ask the umpires to review a close play in the last three innings. Chances are, the umpire will grant the request. And, yes, the umpire can also decide to take another look after the sixth even if a manager who is out of challenges doesn't ask.
How many camera angles will be available to replay officials?
The Replay Operations Center is set up to take feeds from as many as 12 cameras. If there are more, the best angles will be chosen before the game. The replay official also has access to any replays shown by the network(s) covering the game.
There should be at least seven or eight cameras at each game. And each stadium has installed a "high home" camera to, among other things, help the replay officials place runners as needed.
What part of a close play will the umpire look for?
The manager must specify what part of the play he's challenging. But he can challenge more than one aspect if he wants.
Will this eliminate managers coming onto the field to argue?
It isn't expected to. MLB executive vice president of baseball operations Joe Torre, a Hall of Fame manager, said Wednesday that running out to argue is an instinct and there will also be times when a manager gets into a heated discussion to defend one of his players. Just because he comes out of the dugout, he doesn't need to challenge. But after a certain point, the umpire will ask him whether he intends to challenge or not and he'll be expected to respond in a timely manner.
What's to prevent a manager from arguing to buy time for somebody to watch a replay in the clubhouse and then signal the dugout whether or not he should appeal?
Nothing. In fact, it's encouraged. Each stadium has been outfitted so that both the home and visiting teams have equal access to replays and every team practiced its system for relaying that information to the manager during Spring Training.
How long will challenges take?
That remains to be seen, but the goal is for no more than 60 to 90 seconds to elapse from the time the manager informs the umpire that he wants to challenge to the time the replay official's decision is announced.
Why won't managers throw out a flag like NFL coaches do when they want a play reviewed?
Something along those lines was considered, but it was decided that it was important to preserve the interaction between managers and umpires, including arguments, as part of the character of the game.
Which plays can be reviewed?
MLB's studies show that 86 percent of the challenged calls will involve force plays and tag plays. Other plays that can be reviewed include fair/foul in the outfield only, trap plays in the outfield, hit by pitch, timing plays on whether a runner scored after the third out is made, runners passing each other, ground-rule doubles, fan interference, stadium boundaries and record keeping such as the count, numbers of outs, etc.
That's expected to cover 90 percent of all potential situations.
What is not reviewable?
Among the excluded calls are checked swings, balks, infield flies, balls and strikes, the "neighborhood play" at second base and tagging up to score on fly balls.
What about home run calls and home-plate collision decisions?
There are unlimited reviews at the discretion of the crew chief. The manager may not challenge these plays. Home run reviews will be handled largely as they have been in the past except that the determination will be made in New York, not by an official at the game watching a monitor on site.
Paul Hagen is a reporter for MLB.com.