Atlanta Braves' Omar Infante (4) and Martin Prado, center, celebrate...

Atlanta Braves' Omar Infante (4) and Martin Prado, center, celebrate with teammate Derrek Lee, right, after Lee hit a seventh-inning grand slam off New York Mets reliever Manny Acosta in their baseball game at Citi Field in New York, Sunday, Sept. 19, 2010. Credit: AP

Ask the Mets which of the dozens of disappointments has been most frustrating and they will tell you it's a loaded question. It came up again Sunday after Derrek Lee of the Braves came up with the bases loaded. That is a situation overloaded with trouble for a team that now has given up 12 grand slams.

They don't call a grand slam for nothing. It's usually a big deal, as Lee's was in the seventh inning, turning a 2-2 tie into a win for the title-contending Braves. Not that this year's Mets would know, because they have hit no grand slams. That 12-0 disparity somehow loomed larger than the 6-3 final score.

"It's unbelievable. Not to have one is probably as unbelievable as giving up 12," Jerry Manuel said. "I don't think I've been on a team that lopsided. Very interesting number."

R.A. Dickey (11-7), who lost for only the second time in nine decisions at Citi Field, had to think for a moment before he put the Mets' dirty dozen in perspective. Having contributed to Lee's second-deck shot against Manny Acosta by giving up two singles to start the seventh, Dickey said, "I think it says we have made more mistakes as a pitching staff, to allow home runs, where as an offense, we have missed some mistakes that they have made."

As he was speaking, though, he did change course, like one of his knuckleballs: "But you'd have to go back and watch. I think it's much more of an anomaly than anything else. I don't know if you can dissect it to the point where you can reason it out."

The 12 grand slams are the most allowed by a team since the 2006 Orioles. The Mets' 15-0 streak of slams allowed to slams hit, dating to August of last year, is a record.

A close observer might have seen this one coming. Dickey began the seventh by allowing singles to pinch hitter Melky Cabrera and Omar Infante. Pedro Feliciano retired Jason Heyward on a weak grounder and Brian McCann on a pop-up. In between, an intentional walk loaded the bases.

Manuel brought in Acosta, a righthander, to face Lee, a righthanded batter with 10 previous slams. Acosta allowed one of the more infamous of the dozen slams - a shot by the Rockies' Melvin Mora Aug. 11 when some thought Francisco Rodriguez should have been inserted for a four-out save. Later that night, Rodriguez allegedly punched his girlfriend's father and suffered a season-ending injury.

This time, Acosta got behind 3-and-0, rallied to make it 3-and-2, then watched the ball sail way over the fence. "Manny kept challenging him. He had to, bases loaded and full count," said Bobby Cox, the Braves' retiring manager who was honored before the game by the Mets and left with a grand sweep.

The Mets tried not to see it in any grand scheme.

"I don't think so," David Wright said. "You make mistakes to good hitters, they make you pay."

Angel Pagan said: "This is a crazy game. You're going to see things you've never seen before. I hope it's just a coincidence and it doesn't happen again."

But you'd think by coincidence alone, the Mets would have hit at least one. Time is running out in this season, only a dozen games left.