Opening day showed off the game's newest nod to modern technology in a sport that long relied on the eyes of its umps.
From now on, most every call can be challenged by a manager. When that happens, the final decision will come from a replay booth in New York, rather than the field. And instead of out or safe, fair or foul, disputes will be settled with two words new to baseball's lingo: confirmed or overturned.
Commissioner Bud Selig was at Miller Park in Milwaukee for the first call that got reversed. Minutes later, another ruling got changed at PNC Park in Pittsburgh.
"You know what? They got the play right. That's the bottom line," said Atlanta manager Fredi Gonzalez, who won his challenge in Milwaukee but lost the game.
Baseball was last among the four major American sports to use video reviews. Even though fans had access to high-tech television screens, MLB stuck with tradition and let umpires make the calls.
In 2008, after a series of missed calls in midseason, baseball went to replay to resolve disputes on potential home runs. A few months ago, extra replay was added.
Baseball hoped the reviews would come quickly, and that they would cut down on the wild, arm-waving arguments between managers and umps that often delighted fans.
Of the first four reviews Monday, none took longer than 2½ minutes.
"I think that it sure felt like it was out there 10, 15 minutes," Gonzalez said. "Before tonight's over, I'm going to put a clock on it and see exactly how long it took."
"It's a process that they're looking at two to three years of working through the kinks," he said.
The first use of the increased system occurred in Pittsburgh.
Cubs manager Rick Renteria came out to check after Chicago pitcher Jeff Samardzija was called out at first base by umpire Bob Davidson in the fifth inning. Samardzija himself signaled safe as he crossed the bag.
While discussing the play, Renteria got a sign from the dugout to contest the play. Under the new format, teams are allowed to have someone in their clubhouse watch TV replays and then call the bench to say whether it's worth a challenge.
After a 2-minute wait while the umpires hooked up a headset on the field, umpire Larry Vanover — working in the central replay booth in New York — told them the call was correct.
"It was a combination of Samardzjia's reaction and what we were looking at," Renteria said. "We're still trying to figure out what clear and compelling evidence is. It's a work in progress."
Later, Cubs runner Emilio Bonifacio was called safe at first base on a pickoff play in the 10th inning. Pirates manager Clint Hurdle challenged the call and was right that Bonifacio was really out. Pittsburgh wound up winning 1-0.
In Milwaukee, Brewers star Ryan Braun was called safe at first base for an infield hit in the sixth inning. Gonzalez contested the call and, 58 seconds later, the ruling was overturned.
"I had a pretty good idea that I was out," Braun said. "For all of us, we just hope they get it right, and they did get it right."
Brewers manager Ron Roenicke didn't use his one challenge — if they're right, they get another. He did run out to second base to discuss a call with an umpire, but declined to contest it after getting a sign from the dugout.
"It's kind of weird going out there. You used to go out there to kind of argue with the umpire. Now you go out there to say, 'Hey I didn't see it good. What did you have?'" Roenicke said. "Then I'm just waiting to get a signal, so it's quite a different. It probably works out better this way."
New Washington manager Matt Williams used his challenge in the 10th inning of a 9-7 win over the New York Mets. Even though the Nationals held a four-run lead at the time, Williams wanted to be sure after his runner was called out at first base. The ump got it right.
"I tried to get out of the dugout as quick as possible. You don't want to rub it in there, but we have to do it because it's what's best for our club," Williams said.