Instant replay will be used as somewhat of a last resort. According to 24-year umpiring veteran and crew chief Dana DeMuth, the "old rules" of making calls on disputed home run balls will still be very much in effect.
But if after steps one (umpire makes the call), two (manager argues the call) and three (crew convenes to discuss the call) the umpires cannot conclude whether a home run is indeed a home run, they'll turn to the newest step -- instant replay -- to help make the correct determination.
In the past, when an umpiring crew would gather to discuss -- and sometimes, overturn -- a call, they would use a democratic system of sorts. If they were split 2-2, they'd stick with the original call.
Now, if they're split, they'll turn to instant replay to serve as the tie-breaker.
"If we're split on it, with our small little democracy, we'll give the benefit of the doubt and look at the replay and if that can show, without a doubt, that I'm right, or show, without a doubt, that I'm wrong, then that's what we go by," DeMuth said.
But if the crew convenes and the umpire who made the call is unequivocally positive that he made the right call, DeMuth, as the crew chief, has every intention to uphold his umpire's original ruling.
"If my crew member says, 'I know that hit the foul pole, I know it without a doubt in my mind, I heard it, I saw it, this absolutely happened,' well, I'm absolutely going to trust my crew member and say that call stays," DeMuth said. "Foul, fair, that call stays. That's our job.
"I'm not going to let a manager or a coach or a player just try to get away with something either. I'm going to believe my crew. If my crew shows me without a doubt in their mind that they made the right call, I'm sticking with it. I won't even use [instant replay]."
That said, DeMuth is in favor of instant replay to help determine home runs. The cookie-cutter era of ballparks is a part of baseball past, when home runs were easily identified: If it disappeared over the fence or into the bleachers, it was a home run. If it bounced back onto the field, it was not.
These days, with quirky outfields consisting of 10 different dimensions and zig-zag lines, the naked eye sometimes isn't enough to judge a home run. Although DeMuth feels confident that umpires get the calls right the majority of the time, he knows they're not perfect.
"Umpires are human, just like anybody else," he said. "Sometimes you can't tell. That's not saying ballplayers can tell when that question does come up. Most of the time, they can't tell, either."
Umpires want to make correct calls 100 percent of the time, and as replays have shown over the years, in most cases, they do. But errant home run calls have also been an issue over time, and umpires have no problem with asking for help.
"It's here, it's what we're going to deal with, and we can use it as another tool," said crew chief Tim Welke, a 24-year umpiring veteran. "Maybe if we happen to make a mistake we can correct something and our goal as umpires always is to get it right and not affect the outcome of a game. It's another tool we can use to do that and if it helps us correct the mistake, that's a great thing."
Crew chief Derryl Cousins, a big league umpire for 29 years, said instant replay is "probably a good thing."
"When all the new stadiums were built to be fan-friendly and you have places where fans can just reach over the outfield wall, you started to have some controversy," he said. "You never had that before. I think they really want this for the playoffs and the World Series. There's nothing wrong with having to reverse a call if a home run is [initially] called wrong."
For DeMuth, instant replay eliminates the possibility of an umpire reversing a correct call to an incorrect one.
"That's the bottom line to this," he said. "You don't want to change it to something totally wrong, because the other [manager] put on such a great argument, or his ballplayers did, or the fans had a reaction from that section. Everything that weighs on an umpire's mind. I believe this here will definitely help."
Although the instant replay rules may be viewed as somewhat of an insult to umpires, suggesting they can't adequately do their jobs without outside assistance, DeMuth doesn't see it that way. A mechanism to watch home runs in today's quirky ballparks is probably long overdue, and no one sees this more clearly than the umpires.
"If [Major League Baseball] said, 'Every single call you guys make, we go to the replay,' then I probably would have been a little insulted," DeMuth said. "But I've been in that position to where I see a home run, I see it hit the foul pole. Or I see a fan definitely interfere, or a fan not interfere. I have seen it where it's 100 percent in my mind sure.
"And then, with the argument with the manager and the player, well, then all of a sudden I might have doubt. Then I'll call my crew together. Then I'll find out [something different] from my crew, and then I'm like, 'Holy Mackerel.' We're human. Sometimes you pick up a spoon when you need a fork."
Alyson Footer is a reporter for MLB.com. MLB.com reporter Mark Bowman and associate reporter Amanda Comak contributed to this story. This story was not subject to the approval of Major League Baseball or its clubs.