Getting together on Halloween for Game 9 of the World Chess Championship, defending champion Gary Kasparov and challenger Anatoly Karpov tried a few tricks and then treated themselves to a quick draw before their allotted five hours and 40 moves had run out.

Karpov might be haunted briefly by the memory of a misplay that threw away his chance of fighting for a win last night. But it would have required a lot of work for an uncertain outcome, and both players probably needed a rest after the marathon Game 8, which lasted 84 moves and more than 10 hours in two sessions.

Just as losing baseball teams change lineups, chess players tend to change their openings or opening variations after a loss or even a near miss. Kasparov had suffered both, in Games 7 and 8, respectively. So in Game 9, for the first time in the match, the champion abandoned the King's Indian Defense in favor of the Gruenfeld Defense, which usually gives the game a more dynamic pawn structure. This opening is not exactly unfamiliar; he brought it into World Championship play against Karpov during their third match in 1986. The particular system used was played earlier this year in Linares, Spain, in a match between Soviet grandmaster Artur Yusupov and emigre Boris Gulko, but Karpov's 12. Nf3 was a new move.

With the queens off the board, the game settled into a typical Gruenfeld battle, where black's pawn majority on the queenside balances white's strong pawn center. By Move 19, Karpov had the advantage of two bishops against bishop and knight. With 22. Rc4, Karpov made it clear that he would like to put more pressure on black's position rather than win a pawn.

If he had played 22. Bxc5, bxc5; 23. Rxc5, Rb2, Kasparov would have had an active rook and strong counterplay on the black squares, and after 25 Be5, it looked as if Kasparov had managed to blockade white's passed d-pawn. But with 26. g4, Karpov was starting to gain some space on the kingside.

At one point, after 29. g5, Karpov had a better game thanks to the bishop pair and space advantages. Kasparov's pieces served purely defensive roles, and it was a matter of Karpov finding a correct plan. But he used too much time in this search. After 30. ... Bd6, it looked as if Karpov might create some dangerous threats with his rooks on the h-file and his bishop on the a1-h8 diagonal. But with eight minutes left on the clock, Karpov blundered a pawn away with 32. Bd2. By playing 32. Bc1, he would have kept his attacking chances alive. After the loss of the pawn, he had to quickly steer the game toward a drawn endgame with bishops of opposite colors.

The players remain tied at 4 1/2 to 4 1/2. Game 10 is scheduled to begin in New York tomorrow night with Kasparov playing white.

Lubomir Kavalek is a chess grandmaster. Joseph McLellan is a Washington Post staff writer.