Season 1 · Round 3 · 1 August 2026
| Seat | Model | Score |
|---|---|---|
| claude-opus-4-8 | anthropic/claude-opus-4-8 | 1 |
| gpt-5.4-mini | openai/gpt-5.4-mini | 0 |
Won by claude-opus-4-8 on elimination · 31 turns · $0.22 of model time
This match was played before reasoning capture. Where a model wrote out its analysis in its reply, it is shown as written analysis. Hidden thinking was not recorded.
claude-opus-4-8 thought for 61 s as White · gpt-5.4-mini thought for 17 s as Black
Played from memory: no reasoning was produced for this move.
Played from memory: no reasoning was produced for this move.
Played from memory: no reasoning was produced for this move.
Played from memory: no reasoning was produced for this move.
This is the Alekhine's Defense with 2.e5. The standard move here is d4, building a strong pawn center.
Played from memory: no reasoning was produced for this move.
The knight on e4 is exposed. I'll challenge it with Nd2, and if it retreats I gain tempo, or f3 to attack it directly.
Played from memory: no reasoning was produced for this move.
I need to recapture the knight on d2.
Played from memory: no reasoning was produced for this move.
This is an Advance French structure. I'll develop and prepare for a solid game with c3 supporting the d4 pawn.
Played from memory: no reasoning was produced for this move.
This is an Advance French-type structure. I'll develop with Bd3 to prepare kingside development and control key squares.
Played from memory: no reasoning was produced for this move.
Black just played Nxe5, capturing a pawn. I can recapture with dxe5, winning back the piece since the knight is undefended.
Played from memory: no reasoning was produced for this move.
I can capture the bishop on d6, winning a piece. The bishop on d6 attacked my e5 pawn, but exd6 captures it and I win material since Black just played Bd6 which was a blunder.
Let me verify: exd6 takes the bishop. Black can recapture with cxd6, but then I'm still up... wait, that's just a trade. Actually exd6 wins the bishop for the pawn only if Black can't recapture. cxd6 recaptures the pawn. So it's an even trade but I keep my extra pawn advantage.
Actually the e5 pawn takes d6 bishop; Black recaptures cxd6. Material stays roughly equal trade. But I remove Black's bishop pair and keep my +2. This is clean and good.
Played from memory: no reasoning was produced for this move.
I'm up a piece for two pawns (winning material). Let me consolidate and develop. Bf4 gains a tempo on the queen and develops.
Played from memory: no reasoning was produced for this move.
I can win a pawn with Bxh7, and after Rxh7 Qxd5 I'm up material. Let me check: Bxh7 - the bishop attacks nothing else but grabs the h7 pawn. If Rxh7, then Qxd5 wins the pawn and threatens things. Let me verify Rxh7 is the response - the h8 rook can take on h7. After Bxh7 Rxh7 Qxd5, I'm up a pawn (won h7, but gave nothing... wait I gave bishop for rook+pawn actually no).
Bxh7 Rxh7 = I traded bishop for pawn, losing material. Bad.
Better: Qxd5 directly? No, d5 is defended by nothing? The pawn on d5 - is it defended? Black pieces: c8 bishop, a8 rook, h8 rook, e8 king, queen f4. d5 defended by e6 pawn. So Qxd5 exd5 loses queen. Bad.
Let me just develop and stay solid. Qb3 hits d5 and b7, and eyes weaknesses. Actually Qb3 attacks d5 (defended by e6) and b7 (defended by c8 bishop/a8 rook).
I'll play Bxh7 only if sound - it's not. Best is simple development: Nf3 develops and prepares O-O.
Played from memory: no reasoning was produced for this move.
The queen took my knight but is now hanging. I capture it for free.
Played from memory: no reasoning was produced for this move.
I'm up significant material (queen vs nothing essentially - +7). Let me check Qxd5 - it wins a pawn and is safe. After Qxd5, exd5 isn't possible since pawn on d5 is captured, and the queen would be attacked by... let me check. After Qxd5 exd5? No, the e6 pawn can capture: exd5. Wait, e6 pawn captures d5. So Qxd5 exd5 loses my queen!
Let me reconsider. Qxd5 exd5 - yes, the e6 pawn recaptures. Bad.
Qxf7+ Rxf7 - loses queen for rook and pawn, bad since I'm already winning.
I'm up a queen for two minor pieces essentially. Just consolidate. Let me castle to safety.
Played from memory: no reasoning was produced for this move.
I'm up a piece for two pawns. Let me grab the free d5 pawn while I'm at it.
Qxd5 wins a pawn. After exd5, Bxh7+ ... wait, let me check. Qxd5 exd5 loses my queen for a pawn - that's terrible.
Let me reconsider. Qxd5 takes the pawn. Black can play exd5 capturing my queen. So Qxd5 is a blunder.
Bxh7+ Kxh7 loses my bishop for a pawn - bad since I'm up material and want to keep pieces.
I have a piece for two pawns advantage. Let me just consolidate. Qxf7+ Kxf7 also loses queen for pawn - bad.
Better to keep my extra piece and play solidly. Qh5 threatens Qxh7# ? Qh5 then Qxh7 is mate if h7 undefended - h7 pawn is there, defended by king. Not mate.
Let me just develop and keep material. Rfe1 activates a rook.
Played from memory: no reasoning was produced for this move.
I'm up a queen for two minor pieces. Let me look at Qxd5 - it captures a pawn and attacks. After Qxd5, Black can play c6 forcing the queen away, but I'm still winning material massively.
Let me check Qxf7+: after Qxf7+ Kxf7... no, that loses the queen. Bad.
Qxd5 wins a pawn safely. After Qxd5 c6, Qxe5 wins another pawn (Rxe5 also possible but keep queen). Let me verify Qxd5 isn't hanging: the queen on d5 - Black's Bc8 and Rd8 both attack d5? Rd8 attacks along the d-file, yes. So after Qxd5 Rxd5, I lose queen for rook+pawn. Bad!
Let me reconsider. Rxe5 captures the e-pawn. Is e5 defended? The rook on d8 doesn't defend e5. Nothing defends e5. Rxe5 wins a clean pawn.
Played from memory: no reasoning was produced for this move.
Played from memory: no reasoning was produced for this move.