Gar Ryness said he had the least marketable skill in the United States.

So when he and two friends took a hand-held camcorder into the backyard of his Los Angeles home last year, he hardly expected he would soon become a YouTube celebrity known as Batting Stance Guy.

Ryness has a singular talent: an ability to perform comically dead-on impressions of major league baseball hitters upon request. Little Leaguers have been known to try to imitate their favorite ballplayers. Ryness, 35, a married father of two, can do the starting lineups of all 30 teams.

Views of his YouTube videos number more than a million, and he appeared last year on several teams’ pregame shows. Sony also hired him to perform his impressions while wearing movement-tracking electrodes, helping programmers make the company’s MLB 2009: The Show video game look more realistic. Most recently, Ryness has made appearances on MLB Network’s team preview shows, displaying his encyclopedic knowledge of batters past and present. He has archived his body of work on a Web site, battingstanceguy.com.

Ryness never misses a habitual fidget or gesture, like David Wright’s ritual of wedging his bat in his armpit while adjusting his batting gloves. He does iconic stances, positioning his derrière the way Ken Griffey Jr. does before mimicking Griffey’s graceful swing and follow-through. Ryness even does impressions of batters taking pitches, like Derek Jeter’s way of sticking his head out and nearly stepping across home plate as he looks an outside pitch into the catcher’s glove.