Looking at the position carefully (I'm up a knight, black king on g8 with g7 empty), I see a mate: - **Nh6+** — knight from f7 to h6 gives check to the king on g8. - Black king's escape squares: f8 (own rook), g7 (covered by the Bf6), h8 (covered by Bf6 via the empty g7), h7 (own pawn), f7 (occupied). No legal king move. - No black piece can capture the knight on h6 (the h7 pawn only attacks g6; the bishop on c8 can't reach h6; rooks can't either). That's **checkmate**. Playing it.
About this game
Dots Studio: Dots3-Note Preview (free) had White and Ling 3.0 Flash Fin (free) had Black, in round 94 of Free Models. The opening was the Italian Game: Giuoco Pianissimo (C50), reached on move 5. Dots Studio: Dots3-Note Preview (free) won by checkmate on move 20, with Nh6#. White finished 3 points of material up, 21 to 18. Dots Studio: Dots3-Note Preview (free) made 1 illegal move attempt and Ling 3.0 Flash Fin (free) made 1 illegal move attempt.
In their own words
The first illegal move
Dots Studio: Dots3-Note Preview (free) tried Bxb4 on move 7, which was illegal: no legal move in this position matches 'Bxb4'. It played Bb3 instead.
… Wait, e4 pawn is defended by d... no, d4 pawn doesn't defend e4. e4 is defended by Nf3. Black's Nc6 attacks e5? No. Black threatens Bxc3 winning a piece? Bxc3 bxc3 — then black wins the knight pair? White gets pawn. Not a real threat. Black threatens Nxe4: Nf6xe4? e4 defended by Nf3 and d... no. Nxe4 Nxe4 Bxe4? Hmm, Nf6xe4, then Nf3xe4, Bc4xe4. Fine. Let's just play Bxb4. The bishop on c4 can't capture b4. Let me play Bb3 to maintain tension, or d5. Actually let's play Bb3 keeping the bishop safe and eyeing f7. Actually, a good move here is d5 or Bb3. Let's play Bb3.
its reasoning, the end of it — the whole turn is in the replay above The biggest capture
Dots Studio: Dots3-Note Preview (free) took a queen with Qxc5 on move 16.
… The material counts may include something. Let me not worry. Anyway, I'm up a knight? Let's see: white has N f3 and B f6; black has B b6 only. So white is up a knight. Actually white has Q, 2R, B, N vs black Q, 2R, B. So white is up a knight. Good. So I should win. Let's play Qxc5, trading queens, then I'm up a knight. Actually wait — is Qxc5 legal? Queen on d4, c5 has black queen. Yes, Qxc5 Bxc5. Then position: white up a knight and a bishop pair... white has B f6, N f3 vs B c5. Up a knight. Alternatively, Nxe5? That doesn't win material necessarily. Let's play Qxc5.
its reasoning, the end of it — the whole turn is in the replay above The end
Dots Studio: Dots3-Note Preview (free) played the last move of the game, Nh6# on move 20.
… - h7: occupied by black's own pawn → illegal. - f7: occupied by white's knight → illegal (and also attacked by the knight itself, but it's occupied). So the king is in check from Nh6 and has no legal moves. CHECKMATE! So Nh6# is mate! Let me just double-check that the bishop on f6 indeed attacks both g7 and h8. Bishop on f6: diagonals are f6-e5-d4-c3-b2-a1, f6-g5-h4, f6-e7-d8, f6-g7-h8. Yes, f6-g7-h8 is a diagonal, and g7 is empty, so the bishop attacks h8. And it attacks g7 directly. So Nh6 is checkmate. The game is over — I win! Let me make the move Nh6#.
its reasoning, the end of it — the whole turn is in the replay above