In front of 1,000 cheering fans one recent Saturday night in Berlin, Sazhin moved his bishop to go in for the kill and won the world championship of chess boxing, a weird hybrid sport that combines as many as five rounds of pugilism with a game of chess.

The combatants switch back and forth between boxing and chess - repeatedly putting their gloves on and taking them off, so that they can move the pieces around the board without clumsily knocking them over - in a sort of brains-and-brawn biathlon.

''It's the No. 1 thinking game and the No. 1 fighting game,'' said Iepe Rubingh, the sport's 32-year-old founder.

Rubingh's inspiration was ''Cold Equator,'' a 1992 French comic book in which two heavyweight boxers beat each other's brains out for 12 rounds and then play a 45-hour game of chess.