Three months ago Deepak Thosar of Selden, N.Y., was contemplating ways to improve his fantasy baseball team. He noticed that White Sox outfielder Carlos Quentin had lined out on 18% of his fly outs, far higher than the major league average of 14%. Quentin was hitting the ball hard, but right at fielders. So Thosar took a chance on the slugger. He was rewarded as Quentin hit 22 first-half home runs en route to his all-star debut.  Thosar, who has played in the same league since 1992, is part of a growing minority of America's 20 million fantasy baseball players who use advanced stats called sabermetrics to predict player performance. Named for the cabal of math geeks who made up the Society for American Baseball Research (SABR), sabermetrics first emerged in the late 1970s but only gained mainstream recognition after Michael Lewis' "Moneyball" told how Oakland Athletics general manager Billy Beane kept his small-market team competitive with the help of sabermetrics.  These advanced stats come with an exotic nomenclature that seems more sci-fi than baseball: Morp (marginal value above replacement player), Vorp (value over replacement player), Qera (an earned run average projected from strikeout rate) and the Ugueto Effect (when bad players produce anomalously good stats). Expected batting average, a metric concocted from components including contact rate and defensive reaction, replaces traditional batting average, which is still widely used but deeply flawed.  "Batting average isn't a skill unto itself," says Ron Shandler, an early sabermatician and something of a celebrity in fantasy baseball circles. "It's a combination of determining balls and strikes, making contact, and getting lucky enough to get a hit."  Shilling Statistics Shandler, who has been publishing his Baseball Forecaster since 1986, peddles sabermetric stats to avid players on his Web site BaseballHQ.com. For $120 a season, subscribers can access component batting averages and other sabermetric stats for every player in the major leagues. And, since fantasy baseball success is still won by choosing players who are productive by traditional standards, thousands of people are now using sabermetrics to predict the outdated stats it was built to replace.  "There's an awful lot of brainpower going towards those flawed stats," says Christina Kahrl, co-founder of Baseball Prospectus, one of Shandler's rivals. "But fantasy baseball has become the great schoolhouse for sabermetrics. In a sense, these stats become gateway drugs, and it lets us introduce people to more interesting metrics and expand their horizons."  There are only a handful of leagues in the country that use sabermetric categories instead of traditional ones. And if you're among the millions who constitute the latter group, it's not too late to mount a second-half comeback with the help of a little sabermetric research.  Sell high, for example, on overrated players like Twins speedster Carlos Gomez, whose .257 batting average is far above his expected average of .222.  Who's on your fantasy baseball team? Weigh in. Post your thoughts in the Reader Comments section below.  "Here's a guy whose skills are not supporting the numbers he's putting up," says Shandler. "He's a free swinger who only walks in 4% of his at-bats. So all these indicators are pointing to his average coming down."  And take a look at buy-low candidates like Phillies shortstop Jimmy Rollins, last year's most valuable player. He's batting .269 despite an expected average of .317.  But caveat emptor, warns Thosar. "Following your own sabermetric path does not guarantee victory," he says. "However, it protects you from the noise emanating from baseball announcers, ESPN analysts and sports talk ignoramuses. And the process makes sure the participant is a contender every year. What more could a disturbed individual ask for?"
Sabermetrics revolutionized major league baseball. They can also help you dig yourself out of a fantasy baseball slump.