White's king is on a3, my queen on b1, knight on d2, rook on f2. I claimed Qb3# would be mate. Let me verify: Qb3+ — the queen goes to b3, defended by Nd2. King on a3: can it capture on b3? No, defended by Nd2. Escape squares from a3: a2 (covered by queen on b3), a4 (covered by queen on b3), b2 (covered by queen on b3), b4 (covered by queen on b3). Can White block? No, the check is from an adjacent square. Can White capture the queen? Only Kxb3, but it's defended. So it's mate. Let me verify with legal moves.
The legal-move list confirms **Qb3#** is checkmate — the queen on b3 is defended by Nd2, so the king can't capture, and all of a3's escape squares (a2, a4, b2, b4) are covered by the queen. **1...Qb3#** — checkmate and the game is won. Let me play it.
About this game
LiquidAI: LFM2.5-2.6B (free) had White and Dots Studio: Dots3-Note Preview (free) had Black, in round 147 of Free Models. The opening was the Zukertort Opening: Lemberger Gambit (A05), reached on move 2. Dots Studio: Dots3-Note Preview (free) won by checkmate on move 40, with Qb3#. Black finished 15 points of material up, 22 to 7. LiquidAI: LFM2.5-2.6B (free) made 14 illegal move attempts and Dots Studio: Dots3-Note Preview (free) made 2 illegal move attempts.
In their own words
The biggest capture
Dots Studio: Dots3-Note Preview (free) took a queen with Nxd1 on move 6.
… Nxd1 then White plays Kxd1. I'm up a queen for a knight. That's roughly +6 in material. Total would be +12. Great. Alternatively, is there a fork or something bigger? Nd5 threatens... Nc7 fork? Nd5 attacks c7, e7, f6, b6, b4, f4, c3, e3. Not a fork on king and queen. Qxd4? No. Nxd1 is clearly best — win the queen. Actually, let me double check that the queen on d1 isn't defended by something else making it not a free capture. Defenders of d1: king e1 (yes). So it's defended by the king, meaning it's a queen for knight trade — still great since I'm already up a piece. Let me play Nxd1.
its reasoning, the end of it — the whole turn is in the replay above The first illegal move
LiquidAI: LFM2.5-2.6B (free) tried Nd4 on move 9, which was illegal: no legal move in this position matches 'Nd4'. It played Rb1 instead.
… Unless... wait, the FEN "R1BnK2R" breaks down as: - a1: R - b1: . (empty) - c1: B - d1: n (knight) - e1: K - f1: . (empty) - g1: . (empty) - h1: R So the knight is on c1, not d1. And d1 is empty. So Kxd1 would be illegal. Let me just pick "Rb1" - moving the rook to b1 to support the king. This is a reasonable move. Actually, I realize I should be careful. The legal moves list is authoritative. Let me just pick one of those moves. I'll go with "Rb1".
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, Qb3# on move 40.
… White's king is on a3, my queen on b1, knight on d2, rook on f2. I claimed Qb3# would be mate. Let me verify: Qb3+ — the queen goes to b3, defended by Nd2. King on a3: can it capture on b3? No, defended by Nd2. Escape squares from a3: a2 (covered by queen on b3), a4 (covered by queen on b3), b2 (covered by queen on b3), b4 (covered by queen on b3). Can White block? No, the check is from an adjacent square. Can White capture the queen? Only Kxb3, but it's defended. So it's mate. Let me verify with legal moves. The legal-move list confirms Qb3# is checkmate. Let me play it.
its reasoning, the end of it — the whole turn is in the replay above