The world chess championship match in Seville, Spain, eased quietly to the three-quarter mark yesterday with a Queen's Gambit Declined played to a 40-move draw.

This leaves the match score tied at 9 to 9, but with a continuing advantage to defending champion Gary Kasparov, who keeps his title if the 24-game match ends in a 12-12 tie.

Kasparov, playing white, used Game 18 to test challenger Anatoly Karpov's will to win, and his acumen in the Queen's Gambit. It was the first time in the current match that the players used the solid Tartakover Variation, a system seen quite frequently in previous matches between the two.

Kasparov chose a not-very-aggressive variation, one that gives white a microscopic but not decisive edge, worked his way into a protective position from which it would be hard to lose, and sat tight. This answered -- at least for now -- the outstanding question about his current match strategy. The champion announced, in effect, that he is content to coast on the small edge he holds with an even score -- to keep the championship by not losing rather than beating his opponent. Kasparov is not taking chances.

His message to Karpov was: "I'm all right; trying to win a game is your assignment." In a sense, this attitude resembles that of Karpov in the first match between these players after he had secured a 5-0 advantage. He settled back and stopped taking risks, hoping he could win by a 6-0 score as Bobby Fischer had done in some of his preliminary matches for the 1972 world championship.

The difference is that while winning six games, Fischer allowed no draws, while Karpov sat through one draw after another for months as his strength slowly ebbed and Kasparov's returned. That cannot happen in this match, however, since it is limited to 24 games.

In the variation Kasparov chose, white creates an isolated black pawn on d5. Kasparov managed to do this, but so much material was exchanged in the process that he then had trouble taking advantage of black's slightly uncomfortable position. The isolated pawn is not totally ineffectual in this variation when the blockaded square in front of it is controlled by black. Since Karpov's black-squared bishop gave this protection, Karpov had not much to worry about.

In the endgame, after further exchanges, Kasparov had only an active rook on the seventh rank -- an advantage that is, all by itself, hard to convert into a win. When Kasparov began to move his king into action, Karpov was ready to attack the white pawns, and Kasparov could not eliminate his opponent's pawns without leaving some of his own unguarded. In the final position, it is likely that white will end up with an extra pawn, but it is still a theoretically drawn position.

Grandmaster Lubomir Kavalek contributed to this report.