The race — promoting with check

White wins White to move · Pawn endgames · Difficulty about Elo 1100

The plan

Both pawns need three steps — by plain square-counting that would be a flat draw. But counting is only half the truth: what matters is HOW the queen appears. Here the black king stands on the same diagonal as White's queening square, so the new queen arrives WITH CHECK. Black has to parry instead of promoting himself, and the queen then picks up the pawn left standing. How much everything depends on this single tempo is shown by the measurement: of nine possible moves exactly one wins, and the other eight don't merely draw — they LOSE, because the black king then steps into the square of the white pawn and keeps his own. The second and third white moves, too, are each again the only one that holds the win; three moves in a row with no choice at all. The counter-test is even clearer: move the black king a single square off the diagonal, and the same position with the same material is only a draw. So before every race, two questions: who promotes first, and does it come with check?

Rule of thumb: in a race, what counts is not the queen that arrives first, but the queen that arrives with check.

Why this level: Promoting with check — calculation in the race

The solution, move by move

1. 1. c6 Run immediately — the ONLY winning move of nine. The other eight actually lose: Black would step into the square of the c-pawn with Kf5 and keep his own (sideline).
   Sideline 1. Kc2 A wasted tempo — and the win turns not into a draw but into a loss. Eight of the nine moves do exactly that. 1… Kf5 The ONLY winning move for Black: straight into the square of the c-pawn. Now the white queen never gets onto the board. 2. c6 Ke6 Again the only move — the black king stays exactly one step ahead of the pawn. 3. c7 Kd7 And again: the king places itself in front of the queening square. The c-pawn is done for. 4. Kd3 h3 Only NOW does his own pawn run — undisturbed, because the white king stands far too far away. 5. Ke4 h2 The only winning move, and an easy one: the pawn promotes, and White has nothing against it. A single king move at the very start turned the game around.
2. 1… h3
3. 2. c7 Again the only move. There isn't a single moment for thought in this race — every tempo is spoken for.
   Sideline 2. Kc3 The same hesitation one move later — and the difference is instructive: here it costs only half the point instead of all of it, because the white king only just catches the h-pawn. Even so, eight of nine moves spoil the win. 2… Kg5 The black king stops the c-pawn, White the h-pawn. Both races are over before they began. 3. Kd4 Kg6 4. Ke5 Kh7 5. Kf6 h2 The only holding move — and it is enough: the pawn falls at once, but bare kings mean a draw. One tempo was the difference between a whole point and half a point.
4. 2… h2
5. 3. c8=Q+ CHECK — that is the whole difference. If the black king stood just one square off this diagonal, the position would be a measured draw.
6. 3… Kg3
7. 4. Qa8 The queen takes the long diagonal to approach the h-pawn from behind. Only three of the twenty-nine queen moves still win here.
8. 4… Kf2
9. 5. Qh1 The only winning move of twenty-nine: BEHIND the pawn. From h1 the queening square is blocked forever.
10. 5… Kg3
11. 6. Qf1 The pawn is dead, the white king strolls up at leisure. It was the check on the third move that won it, not the race.

More in Pawn endgames

• The trebuchet — whoever moves loses White wins
• The queen skewer — curse of the long diagonal White wins
• Key squares — the sixth rank always wins White wins
• Shouldering — leading with the shoulder White wins
• Distant opposition — opposition at a distance White wins
• Doubled rook pawn — the corner holds two as well Draw