Perpetual Check

I often hear it stated that one of the ways the rules of chess facilitate a draw, or result with no winner is perpetual check. In fact, there is nothing in the rules about this option. Rather, the rules of chess provide for a draw by repetition.

9.2 The game is drawn upon a correct claim by the player having the move, when the same position, for at least the third time (not necessarily by a repetition of moves):
a. is about to appear, if he first writes his move on his scoresheet and declares to the arbiter his intention to make this move, or
b. has just appeared, and the player claiming the draw has the move.
FIDE Handbook, http://www.fide.com/fide/handbook.htm

US Chess Federation Rules, under which I play, are similar.

Perpetual check is not a rule, but a means to draw by repetition. When a player is unable to avoid endless checks, he or she has no way to avoid draw by repetition.

In one of the variations given in Judit Polgar's annotations to her brilliant win against Levan Pantsulaia in the eighth round of the European Individual Championship, she offered this position after an oversight by Black. See yesterday's "King Safety" for the game.

In the game, Polgar played 31...e3. This position arises after the alternative 31...Qa4+ 32.Nb3, and then instead of the necessary 32...e3, the blunder 32...cxb3.

White to move

White can endlessly check the Black king from f5 and c8. A beautiful attack ran aground because the Black king, too, was vulnerable.