It would also have made you one of the people addressing a vexing problem at the core of professional sports: how to appraise talent. “The most im-portant thing in sports by far,” says Daryl Morey, the 34-year-old assistant general manager of the Houston Rockets, “is getting the right players for the right price.” But the front offices of pro-sports franchises usually don’t even know how to put an exact value on what a player has done, much less on what a player will do. Five years ago, major league teams overvalued hitters’ batting average, undervalued on-base percentage, and hadn’t a clue how to assess defense or baserunning. But last year, the Oakland Athletics’ front office will tell you, on-base percentage was actually an overvalued statistic.

In sports other than baseball, games are far messier, from a statistics viewpoint at least, and the problem of valuing players even bigger. Fifteen years ago, the left tackle was the lowest-paid player on the football field; now he is the second highest, after the quarterback. Why? Did the game change that much, or are teams just following a fad? Basketball teams have always paid top dollar to the players who score the most, even though three professional economists, in their analysis of pro sports The Wages of Wins, argue that scoring average is the single most overvalued trait in a basketball player.

And if you think it’s hard to value a player who has been in the N.B.A. for a few years, you should try putting a number on, say, Ohio State’s star freshman center, Greg Oden, who’s projected to be the first pick in the N.B.A. draft. The less of a track record players have, the greater the uncertainty about their future. So the deepest mystery in every sport is the value of a player before he or she has been tested by the pros. Enter Wall Street, with its roughly 250 years of experience assigning prices to assets with uncertain futures.

If you had to pick a moment when Wall Street put itself on a collision course with professional sports, you could do worse than 1994, when Ken Mauriello and Jack Armbruster quit their jobs analyzing and trading futures and options on the Chicago Board Options Exchange to design a system for valuing baseball players. The two went from looking for inefficiencies in the financial markets to looking for inefficiencies in the market for professional athletes, but their approach to the problem remained essentially the same: Collect better information and analyze it more intelligently. Compared with the financial markets—which were big, smart, and mature—baseball offered a huge trading opportunity. “In baseball,” says Mauriello, “you had the inefficiencies that come from sloppy data.”

With that in mind, they created a system called advanced value matrix, or A.V.M., which eventually transformed conventional baseball accounting. Under the traditional approach, when Yankees third baseman Alex Rodriguez hits a lazy fly ball that the center fielder loses in the sun, A-Rod would be credited with a double, the pitcher debited with giving up the double, and the center fielder would have nothing registered for or against him. But A.V.M. would measure the angle and velocity of the batted ball (out of 10 possible combinations) and the spot (out of 8,000 possible) in the outfield where it landed. This information would then go into an arduously assembled database of tens of thousands of baseball games, where it would emerge that, in this example, A-Rod’s fly ball was identical to, say, 5,000 others over the previous 10 seasons, and 97 percent of the time it was an out, not the double A-Rod was credited with. And so, in A.V.M., A-Rod made 97 percent of an out, the pitcher is credited with getting 97 percent of an out, and the center fielder is debited for failing to make a routine play.

Baseball people have always known, of course, that luck plays a role in the game. But they assumed that good luck and bad luck even out—and they don’t. Pitchers, especially, are at the mercy of forces beyond their control. At the end of each season, you will find a bunch who’ve been unlucky but who, you can be fairly certain, will rebound and another bunch who’ve been lucky but who will likely regress in the next season. This would seem to be useful information for any baseball team to know. And when Mauriello and Armbruster shopped their system around to major league teams, one person who was particularly interested was a recent Harvard graduate named Paul DePodesta, who had eschewed a career on Wall Street to take an internship for the Cleveland Indians. “It opened my eyes,” DePodesta says. “The system extracts the element of luck.”