But that's it. Tony La Russa, one of the architects of the rule, likened it to having Chipper Jones out of the starting lineup and available to pinch-hit.
"So you've got this weapon on your bench," La Russa said. "When do you use it?"
Does a manager use his challenge on a mundane call early in the game? Or does he wait for that inning he believes is more likely to decide a game?
Even if he uses his challenge and gets a call overturned, he has just one more chance. Knowing when to use the challenge is an entirely new layer of thought.
As La Russa said, "We told our managers during the Winter Meetings, 'You have tough decisions during the game. That's what they pay you for. If those bother you, you're in the wrong job.' You're taking your best guess. It's the opportunity to change a game-changing play that goes against you."
La Russa envisions entire series when a manager doesn't use a single challenge. Other games, though, it's a matter of picking their spots.
After the sixth inning, umpires can initiate their own challenges. If you're wondering why there aren't unlimited challenges, it goes back to pace of the game, to doing something completely different without losing the rhythm that is a day at the park.
Two things to remember: Today's rollout is Expanded Instant Replay 1.0. It's so new and different that it's almost certain to be imperfect.
Braves president John Schuerholz called it "a three-year rollout." He means that he expects the whole system to be reviewed -- and perhaps tweaked -- again and again.
"At the end of year three, we expect it to be as near perfection as humans can get in this system," Schuerholz said.
Another thing to remember: Commissioner Bud Selig's committee on replay included La Russa, Schuerholz and Joe Torre.
If baseball has three better people to design this kind of system, it would be difficult to find them. They are the gold standard for everyone in baseball. Torre and La Russa have managed 9,426 regular-season games between them and won the World Series seven times. Both will be inducted into the Hall of Fame this summer.
As for Schuerholz, he's one of the six or seven most respected people in the sport, and he, too, will someday have a plaque hanging in Cooperstown. He's also about to become a 75-50-25 man, perhaps the only one ever. (That's 75 years old, 50 years in baseball, 25 with the Braves.)
If these three can't get it right, it's unlikely anyone could.
"They worked tirelessly on this," Selig said.
They found that the system was way more complicated to implement than to discuss. For instance, each ballpark will be fitted with enough cameras to give Major League Baseball Advanced Media 12 angles of every play.
Baseball will add eight new umpires to rotate into MLBAM's New York offices to make the calls on replays. Umpires insisted that if they were going to blindly trust someone watching the game on television, they wanted it to be one of their own.
Back to strategy. Every manager will have someone watching a television feed of the game, and when there's a close call, he or she will watch the replay to see if the call should be reviewed.
He (or she) will have a phone line to the dugout and will attempt to get the information to the manager before the pitcher throws the next pitch.
And if you think players will stall to wait for the call, umpires will be alerted to be on the watch. There could be fines issued.
For fans who love complaining about their hometown manager -- and you know who you are -- this is another dream come true. Best of all, replays will be shown on stadium video boards, including the replays that are used to decide a call.
That's the fun part of all this. But that's just a small part of this story. This day was about something larger, something that changed the game seismically.
"It's the first time in the history of the game where managers have the opportunity to change the call of a play that may have cost 'em a game," Schuerholz said.
Selig clearly was pleased that it finally had been worked out, that the umpires and players had both signed off and that the transformation of the game on his watch had gotten another chapter.
"It's another one in a long list of changes that will make this sport even better," Selig said.