PITTSBURGH — Most everyone wants one.

Fans dive for one. They wrestle each other for one. They even yell, beg and plead for players, security guards, ushers and ball boys to give them one.

Baseballs, both foul and fair, are a hot commodity to fans at ballparks from San Diego to Boston.

PNC Park is no different. And Pirates first baseman Doug Mientkiewicz can't figure out why.

"I don't quite get the infatuation with a baseball," Mientkiewicz said. "They treat it like it is a piece of gold. I don't have the slightest idea why they go crazy and dive all over the place for one."

Mientkiewicz got a first-hand look at how badly fans want to get their mitts on a baseball July 13 against the St. Louis Cardinals.

St. Louis slugger Albert Pujols hit a soaring pop-up that drifted toward the stands on the first-base side.

Mientkiewicz gave chase and leaned over the railing into the crowd to try to catch the pop fly, but a fan reached out for the ball, too. Neither the fan nor Mientkiewicz made the catch.

"Usually, at home, the fans will get out of the way," Mientkiewicz said. "(It's frustrating when they don't), especially when it is Albert Pujols hitting. It's kind of an important out for us."

But trying to catch a baseball at the ballpark is as much a part of the experience as hot dogs, Cracker Jacks and the seventh-inning stretch.

Baseball is proud of its role as the souvenir city of the sporting world. Where else can a fan leave with a piece of the game?

Modern fans can thank Reuben Berman for that.

In 1921, Berman caught a foul ball at the Polo Grounds and wanted to keep it. When the New York Giants forced him to hand it over, Berman sued — and won.

Since then, fans have fallen over themselves — many times literally — for the chance to take a baseball home.

"It's just part of going to the ballpark," said Gina Shider, who lived inBeaver Falls for 18 years before moving toSan Diego. In town visiting family and taking in a Pirates game, she held firmly in her left hand a baseball given to her by an usher. "It's fun. It's exciting."

And for many fans, it's darn near impossible.

During the Pirates-Colorado Rockies game Monday night, about 85 balls were either hit or tossed by players, coaches and ball boys into the stands. With 15,303 fans in the seats, that averages out to one souvenir for every 180 people.

Perhaps that is why fans react to a ball hit into the stands like sharks to chum in the water.

Tammy Shuster of Denver, in town visiting friends and watching her Rockies play, has been to hundreds of games in her lifetime. She has yet to catch a baseball.

"But I'll keep trying," she said. "I won't fight for one, but if one rolls my way, I'm gonna grab it."

Before the game, fans lined both dugouts hoping to get a baseball. When a player or coach came near, they called out to him.

In the midst of the chaos stood Maria Pugliese, 15, of Minneapolis. She didn't say a word, but Rockies catcher Yorvit Torrealba tossed her a baseball.

"I wanted one," Pugliese said. "But I didn't expect to get one."

Mientkiewicz said the key to getting a baseball is appearing as though you don't really want want one, just like Pugliese did.

"Everyone wants something, whether it is a ball or bat" Mientkiewicz said. "It's usually the people who don't scream and yell all the time that get it. The people who scream and tell drive you absolutely insane. They don't get anything."

While it might be much easier to buy a baseball at a concessions stand or store, the draw of catching one at a game is simple: the story attached to it.

"Buying one isn't the same," Shuster said. "There's no story behind it. You can't tell your friends, 'Hey, I bought this ball at Dick's.' But you can say, 'Hey, I got this ball at a Rockies game."