Chess

THE MOST elegant endgame studies start in credible, game-like positions, then, in a long and forced sequence of moves, drag the pieces inexorably towards an almost unbelievable finish. Today's position, composed by Andre Cheron in 1964, is a stunning example.

It is White to play and win and the task is clear: to blockade the black pawns with bishop and knight, then wander in with the king to capture them, finally mating with bishop and knight. (In the pure world of studies, the tricky bishop and knight mate may be taken for granted.)

The first problem though is to stop those pawns, so White begins 1. Nf4 guarding the d3 and

e2 squares. Play continues 1 . . . d4] 2. Bf6 e2] and White must think again. 3. Nxe2 d 3 4. Nc3+ Kc2 lets Black draw easily. The d-pawn, once it reaches d2, is bound to cost White a piece. If White is to stop the pawns, he must organise a blockade on a black square, controlled by both knight and bishop, but it is hard to envisage how both pawns can be held up in such a manner.

So it has to be 3. Nd3 Kc2 4. Ne1+ Kd2 5. Bh4. White has a black-square blockade, but now comes 5 . . . d3 6. Kg6 Kc3 (6 . . . Ke3 7. Kf5 d2 8. Bg5+ wins for White) 7. Bd8]

Now 7 . . . d2 loses to 8. Ba5+, so Black plays 7 . . . Kd2 8. Ba5+ Ke3 when the threat of d2 is real. 8. Bd8 Kd2 leads only to a draw, so White plays 8. Kf5]] and you can work out the beautiful finish yourself. (Answer tomorrow.)

(Graphic omitted)