To most average fans, it looks more like a nervous twitch from a player or a coach -- not anything significant.

Maybe it's the second baseman opening or closing his glove in the direction of the shortstop. It could be the third-base coach simply clapping outside his box near the line, touching the bill of his cap instead of his left arm or shouting words of encouragement. It even might have been as miniscule as the way a pitcher tilts his glove from fastball to curve.

It doesn't sound very telling, does it? To tried and true walking books of baseball knowledge such as Joe Nossek, Gene Mauch and Joey Amalfitano, those little movements provided an edge for their respective teams that often couldn't be delivered by a 95 mph fastball or a 40-home run slugger.

The aforementioned coaches and managers were just a few of baseball's top sign stealers, a somewhat complicated process that resembles more of an art form than a common crime on the diamond. Some form of sign stealing has been part of the game since the first pitch was thrown.

It's not exactly a skill taught at Spring Training -- but it's an unspoken psychological edge that most teams relish.

"We don't have anybody like that, but it's definitely something I'd welcome," said Oakland third baseman Eric Chavez of sign stealers. "If for no other reason than it might freak the other team out. If you've got someone who's great at stealing signs, the word's gonna get out pretty quick. And when it does, teams will change what they do when playing you. It just gives them one more thing to worry about."

"It's not an easy thing to do," added Detroit catcher/infielder Brandon Inge. "Since I've caught, I can tell different mannerisms they're doing. A lot of times, they'll use a hotspot, like touching your hat, or hands-off, hands-on, look to the left, look to the right. There's a thousand different ways you can do it. It's the art of stealing."

A common belief is that signs actually began in the game during the late 1800s, when William "Dummy" Hoy first became a professional player. Profoundly deaf due to a childhood bout of spinal meningitis, Hoy had the third-base coach signal to him what call was made by the umpire so he wouldn't have to spin around and read the umpire's lips.

This situation actually led to umpires making their calls with hand and arm gestures for everyone to witness.

"If you're doing it and the other team picks up that you're doing it, you're going to have to pay the consequences. It's just how it works. You'd better hide it well if you're doing it." —Brandon Inge

Amalfitano, a longtime third-base coach for the Los Angeles Dodgers, started his process by initially trying to read the manager. If "you can't do business there," according to Amalfitano, you move on to the third-base coach and then to the body language of the runners or hitters.

For Nossek, who turns 64 in November and served as bench coach for the White Sox from 1991 until his retirement during Spring Training, stealing signs started as a hobby to pass the time when he was a journeyman player during parts of six seasons with Minnesota, St. Louis, Kansas City and Oakland. He wrote down all the information he had observed and kept it in a file. If a certain guy would come back into his sights, Nossek would know what to watch.

The sign might be a certain indicator used by a third-base coach for the bunt, or a signal from the dugout consistently used on hit-and-runs.

"Joe Nossek was very good at it," said Mariners bench coach Rene Lachemann. "Gene Mauch was supposed to be very good at it. Also, Tony La Russa is very good at it. He's also very paranoid about it.

"He's so afraid that someone will steal a sign that he changes them just about every day, it seems, and will have different guys on the bench give them. One day it's the trainer, one day it's the pitching coach, one day it's the batboy. What makes a good sign stealer is remembering all of the things you have used before, whether it's touches as an indicator, or counts or whatever."

"If you've got someone who's great at stealing signs, the word's gonna get out pretty quick. And when it does, teams will change what they do when playing you. It just gives them one more thing to worry about." —Eric Chavez

Understanding in-game situations and simply being observant are two of the best sign-stealing tools. White Sox bullpen coach Art Kusnyer remembers a time, while coaching against Boston, when he gradually began to notice odd movements by the second baseman. He would put his right foot back before one pitch, then get set, then put his left foot back before getting set again.

Kusnyer started watching the pitches that followed the second baseman's fancy footwork.

"It was fastball, right foot, and breaking ball, left foot," said Kusnyer with a smile. "So I called the dugout and told them. The hitters would get up and look at second base and then look at the pitcher.

"Dwight Evans was in right, and wanted to know what was coming so he could react to it. Some guys want that edge. Some guys would give it behind their back with fingers."

Nossek recalled a few occasions where Lou Piniella became angry when he knew the White Sox had picked up his signs, and accused Nossek and the White Sox of cheating. But for the most part, the practice is accepted if pulled off ethically.

And in this age of advanced technology, with countless camera shots from every imaginable angle, the art of sign stealing has become more of a talked-about rumor. It's a perception, a shadow of a doubt that the opposing team has something.

It's more about knowing the opposing team's tendencies and then acting on that knowledge.

"Stealing signs is a difficult thing to do," Lachemann said. "The game has changed so much that sometimes you are better off looking at counts and seeing if there is a pattern there."

"If you're doing it and the other team picks up that you're doing it, you're going to have to pay the consequences," Inge said. "It's just how it works. You'd better hide it well if you're doing it."

"Don't whine. Play the game," said Rockies manager Clint Hurdle. "It's like a guy who doesn't have a very good poker face. It's not my fault he can't bluff."

This story was not subject to the approval of Major League Baseball or its clubs.