Chess players may be the most deliberate gamers in the world. Every move can be fatal, every action the prelude to a winning play 15 moves down the line. Chess players take numbers and statistics real serious, which has led to an interesting dilemma in the world of professional chess: If the numbers say someone is cheating, is that proof enough to indict them? We're not talking statistics culled from a few games--we're talking numbers laboriously compiled from thousands of games and millions of moves, compared against the best computer chess programs and analyzed to determine how an individual performance compares to a player's chess rating.

There's currently a hubbub over the performance of Bulgarian Borislav Ivanov, whose rating of 2227 barely qualified him as a master before he took third place in a recent tournament, winning five matches against four grandmasters and a master. Kenneth Regan, an associate professor at the University of Buffalo (and "international master" at chess), has developed a mathematical model he called the "intrinsic rating" to determine the skill level of chess players. Ivanov's performance at the tournament earned him a rating of over 3000, well above the world record of 2861. Ivanov's overall rating isn't that high, but Regan's math indicates that he either played one hell of a tournament, or that he found a way to cheat.

Regan writes that he expects something like a 1000-1 deviation to come from studying the performances of a thousand chess games, and that those odds simply aren't proof enough of cheating in chess. But he compares Ivanov's performance to a million-to-one shot, which is, well, a little more suspicious. Adding to the suspicion, one of Ivanov's two losses came after the organizers stopped broadcasting the games online. Ivanov was searched after the tournament, but the organizers found nothing in his pockets (or in his pen) to indicate cheating. So far, cheaters at major tournaments have always been caught. Is he the one that got away?

Maybe--if not, he played an amazing few games of chess. Cheating's predictably becoming a bigger issue for a game that relies on pure brainpower, and at some point mathematical modeling may prove complete enough, or convincing enough, to stand alone as evidence of foul play. Regan found that Ivanov's plays matched a computer program's by 70 percent. That's a compelling indication that foul play is at hand. But does that constitute proof?

Computers are both a curse and potential salvation for the game; since IBM's Deep Blue beat world champion Gary Kasparov in 1997, computer processing has grown enormously. When computers enter the picture, odds are good a human competitor is going to lose.

Having a computer on hand obviously makes cheating a breeze; the challenge is getting away with it.

In 2012, a high school student got caught cheating with a PDA meant to be running eNotate, a chess scorekeeping app. eNotate is, supposedly, hack-proof, making it impossible to boot up another app (like a chess program) while its running. Which means the kid was either an impressive hacker, or ballsy enough to boot up a chess program instead of the notation software. He won nine tournaments--potentially all with the use of the device--before getting caught.

Having a computer on hand obviously makes cheating a breeze; the challenge is getting away with it. At some point, tournament organizers may start holding their most important matches in isolation, cutting players off from any possible access to the outside world. That should work for awhile--until brain implants are in vogue, at least.