Andrelton Simmons lifted a pop fly into shallow left field. Not a hard-hit ball, by any means, but at least 50 feet beyond the infield.

St. Louis shortstop Pete Kozma drifted back, throwing up his hand in that universal baseball gesture, "I've got it." Only one problem. Right before the ball came down, the rookie veered out of the way, apparently thinking left fielder Matt Holliday was going to take it.

The ball dropped harmlessly in the grass. The crowd roared, thinking the Atlanta Braves had loaded the bases with one out. Only one problem. Standing nearby, umpire Sam Holbrook had thrown up his right arm, signaling Simmons was out.

This grab was made by the infield fly rule.

The first wild-card playoff game in baseball history turned out to be just plain wild Friday, thanks to a complicated rule that has long been part of baseball, even if many people — even hard-core fans — don't know exactly what it is. The disputed call led to a protest by the Braves — which was quickly denied — and an ugly display as fans littered the field with debris, causing a 19-minute delay.

That only delayed the inevitable for the Braves. The Cardinals moved on to the divisional series against Washington with a 6-3 victory in baseball's new one-game, winner-take-all playoff round.

"You never want to see something get violent like that," said Braves third baseman Chipper Jones, who played his final game. "But when you've got (what is essentially) a Game 7 and your whole season is on the line ... things like that are going to happen."

What, exactly, did happen?

The infield fly rule gives umpires the discretion to call an automatic out on a popup with more than one runner on base, largely to prevent the team in the field from intentionally letting the ball drop so they can get an extra out, since the runners can't drift too far away from the bag for fear of getting doubled off after the catch.

"The infield fly rule is to protect the runners, really," Atlanta manager Fredi Gonzalez said.

This time, it cost the Braves.

At issue was whether Kozma had established his position to make the catch, and whether it should have been made under any circumstances on a popup that far beyond the infield.

"I thought we have a legit beef," Gonzalez said.

Joe Torre, who played and managed for both the Braves and the Cardinals, was on hand as the executive vice president of baseball operations. He turned down the protest, ruling it was a judgment call by the umpires.

"Not that you can't protest," Torre said. "But you can't uphold a protest based on that."

Besides, both Torre and Holbrook thought it was the right call.

"It's all judged on what the fielder does," said the umpire, who was stationed down the left-field line as part of the expanded six-man crew that is used in the playoffs. "Once that fielder establishes himself and he has ordinary effort on the ball, that's when the call is made. So it wouldn't matter whether it was from third base or on the line out there. It's all based on what the fielder does. That's what I went on, and that's what I read."

The Braves saw the play differently, of course.

"I thought the shortstop had to go way out there to make a play on that fly ball, and I think we've got to take into account the crowd — 50,000 people yelling — and I thought there was some miscommunication between Holliday and Kozma," Gonzalez said. "I thought we were going to catch a break there."

No one was pleased about the way the crowd reacted after the call. Braves president John Schuerholz issued an apology to Major League Baseball and the Cardinals, blaming a small group of fans who "acted in a manner that was uncharacteristic and unacceptable."

As the Cardinals celebrated another playoff triumph in the clubhouse, someone screamed, "Infield fly!"

"I understand that the Braves are upset by what happened," manager Mike Matheny said. But, he added, "The umpires were out there. It was the right call."

Besides, the umpires had nothing to do with Atlanta's three throwing errors, which allowed the Cardinals to score four unearned runs. Without the defensive miscues by the NL's top fielding team, that call in the eighth would have been an afterthought, not one that nearly caused a riot.

"Ultimately, when we look back on this loss, we need to look at ourselves in the mirror," said Jones, whose errant throw in the fourth led to three runs for the Cardinals. "Three errors cost us the ballgame, mine probably being the biggest. Did (the infield fly rule) cost us one out? Did it cost us one run, possibly more? Yes. But I'm not willing to sit here and say that call cost us the ballgame."

On Twitter, outfielder Jason Heyward said: "When you don't have anything positive to say it's best to not speak," then thanked Braves fans for their support this season.

Braves starting pitcher Kris Medlen tweeted: "Can't point fingers at anyone but ourselves. Didn't bring our A game as a team and the cards capitalized."

The play will certainly lead to a clamor for expanded use of instant replay to deal with an epidemic of disputed postseason calls in recent years — especially with the new one-and-done format.

If nothing else, there were plenty of comparisons to the NFL's much-maligned replacement refs.

"This was an exciting game," Torre said. "I'm sorry about the controversy. It's certainly not something we ever plan on."

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