About this game

Poolside: Laguna S 2.1 (free) had White and Poolside: Laguna XS 2.1 (free) had Black, in round 40 of Free Models. The opening was the Ruy Lopez: Berlin Defense (C65), reached on move 4. Poolside: Laguna S 2.1 (free) won by checkmate on move 18, with Qxd8#. White finished 37 points of material up, 42 to 5. Poolside: Laguna XS 2.1 (free) made 2 illegal move attempts; its opponent made none.

In their own words

1. The first illegal move

   Poolside: Laguna XS 2.1 (free) tried exd4 on move 5, which was illegal: no legal move in this position matches 'exd4'. It played d5 instead.

   … And "Nxe4" which is a knight capturing on e4. But if white has a pawn on d4 and e2, and black has a pawn on e5... then exd4 should work. Unless... wait, could there be a piece on d4 preventing the capture? Let me re-read the board: Rank 4: . . . P . . . . - the 4th square from the left (in h-g-f-e-d-c-b-a order) is the 4th character, which is P (white pawn). OK so the pawn is on d4. And black's e5 pawn should be able to capture exd4. I'm confused why exd4 isn't legal. Let me just try a different approach - let me play d5, which challenges in the center.

2. The biggest capture

   Poolside: Laguna S 2.1 (free) took a queen with Rxe8 on move 12.

   … The rook can capture the queen: **Rxe8+** (rook from e4 captures queen on e8). After Rxe8+, the black rook on f8 must recapture (Rxe8). But this trades a rook for a queen, giving white a massive material advantage (queen is worth 9, rook is worth 5, so white gains 4 points). Combined with the bishop + 2 pawns already won, white would be up a huge amount. Let me verify: the e-file path from e4 to e8 goes through e5 (empty), e6 (empty), e7 (empty), and reaches e8 (black queen). This is a clear path. I'll play Rxe8 immediately.

3. The end

   Poolside: Laguna S 2.1 (free) played the last move of the game, Qxd8# on move 18.

   … ✗ - Kg8: d8-e8-f8-g8, all empty after king moves. Queen attacks g8. ✗ - Ke7: d8-e7 (diagonal), queen attacks. ✗ - Kf7: own pawn. ✗ - Kg7: own pawn. ✗ - Block on e8: no piece can reach e8. ✗ Checkmate! ✓ I'm confident. Let me play Qxd8#. Wait, I should also check: could the king capture the queen on d8? The king is on f8. d8 is 2 squares to the left (along rank 8). The king can't move 2 squares in one move. So no. ✓ And no other piece can capture the queen on d8 (no black pieces can reach d8). ✓ It's definitely checkmate. Let me play Qxd8#.