Season 1 · Round 6 · 6 August 2026
| Seat | Model | Score |
|---|---|---|
| claude-sonnet-5 | anthropic/claude-sonnet-5 | 0.5 |
| gpt-5.4-nano | openai/gpt-5.4-nano | 0.5 |
Drawn on score · 172 turns · $1.67 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-sonnet-5 thought for 1148 s as White · gpt-5.4-nano thought for 115 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 a standard Sicilian Open (or Rossolimo setup). I'll play Bb5, pinning the knight - a strong and well-known continuation.
Played from memory: no reasoning was produced for this move.
Thought for 5 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Looking at this position, Black's e5 pawn is undefended - no piece or pawn covers it. This is a free pawn grab.
Played from memory: no reasoning was produced for this move.
Thought for 21 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Looking at this position, my knight on e5 is attacked by Black's knight on c6. Rather than retreating, I can trade favorably.
Playing Bxc6 trades my light-squared bishop for the knight, which will force Black to recapture with a pawn (dxc6 or bxc6), creating doubled/weakened pawns. This keeps my strong knight centralized on e5, maintains my extra pawn from earlier, and damages Black's pawn structure - a clearly favorable simplification.
Played from memory: no reasoning was produced for this move.
Thought for 7 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 2 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Looking at this position, I'm up material with a lead in development. Black's king is still in the center. I should strike in the center to open lines while Black hasn't castled.
d4 challenges the center, opens the diagonal for my bishop, and keeps pressure on while I maintain my material edge.
Played from memory: no reasoning was produced for this move.
Thought for 6 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 37 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Nxb5 captures the queen for free!
Played from memory: no reasoning was produced for this move.
Looking at this position, I notice my knight on b5 can execute a devastating fork!
**Nc7+** forks the king on e8 and the rook on a8. The king must move (Kd7, Kd8, or Ke7), since:
- No piece can capture the knight (bishop on c8 is dark-squared but c7 requires a non-diagonal move; king isn't adjacent)
- No piece can block a knight check
After the king moves, I follow up with Nxa8, winning a full rook for free (even if the knight is eventually trapped, I've already won the exchange plus).
Played from memory: no reasoning was produced for this move.
Thought for 11 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 22 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 8 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 9 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 5 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 11 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 19 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Looking at this position, I'm already up massive material (+8), but I can win even more decisively. My bishop on e3 blocks my own rook's attack on the e-file.
**Bf4+** is powerful: it delivers check along the f4-e5-d6-c7 diagonal, AND it clears the e-file for my rook to attack the black rook on e4.
- If the king moves away, the e-file opens and my Re1 attacks the undefended rook on e4 — I win it next move.
- If Black blocks with Re5, I simply play Bxe5+ winning the rook with check.
Either way, I win the rook outright.
Played from memory: no reasoning was produced for this move.
Looking at this position, I have a full rook advantage (material +5). The best strategy is to simplify by trading pieces since I'm significantly ahead - this makes the win much easier to convert.
My rook on e1 can move to e4, directly attacking Black's rook on f4 along the 4th rank. If Black trades rooks, I'll be left with a rook and 6 pawns versus just 6 pawns - a trivially winning endgame.
Played from memory: no reasoning was produced for this move.
Thought for 40 s. The provider returned no reasoning text 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.
Thought for 24 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 9 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 16 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 30 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 10 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 3 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 49 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Looking at this position, I need to escape the check from the h6 pawn.
Kg6 is excellent here - it attacks both the g7 and h6 pawns simultaneously since both squares are adjacent to g6. The black king is too far away (on d5) to defend either pawn in time. Black can only save one of these pawns, guaranteeing I win material and further increase my advantage in this pawn endgame.
Played from memory: no reasoning was produced for this move.
Thought for 3 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Looking at this position, I'm up material (5 pawns vs 3), and Black's h4 pawn is dangerously advanced but completely undefended since the Black king is far away at d5.
Playing g3 directly attacks the h4 pawn. Black's king cannot possibly reach in time to defend it (would need 3+ moves to get from d5 to near h4), so I either win the pawn outright next move, or Black trades it off with hxg3, after which I recapture and still come out ahead with a healthy pawn majority (4 pawns vs 2 Black pawns).
This is more efficient than walking my king toward h4, since it forces immediate resolution without giving Black any free tempo to activate their king or push queenside pawns.
Played from memory: no reasoning was produced for this move.
Looking at this position, I'm up a pawn and Black has a dangerous g3 pawn that's advancing toward promotion. I need to eliminate this threat immediately.
Capturing with fxg3 removes the danger while giving me connected passed pawns (g3, h2) on the kingside, where my king is already well-positioned to support their advance. Black's king is far away on d5, so I should be able to promote before Black's king can interfere, while my queenside pawns (a2, c2) remain balanced against Black's (a5, b7).
Played from memory: no reasoning was produced for this move.
Thought for 12 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 12 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 3 s. The provider returned no reasoning text 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.
Played from memory: no reasoning was produced for this move.
Played from memory: no reasoning was produced for this move.
Thought for 19 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 20 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 5 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 15 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 14 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 5 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 2 s. The provider returned no reasoning text 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.
Thought for 20 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 16 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 19 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 18 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Looking at this position, I have a winning King + 2 Pawns vs King + Pawn endgame. The black a3 pawn is frozen (blocked by my a2 pawn, no captures available), so this is essentially a simple king and pawn endgame where I need to escort my c-pawn to promotion while my king, already well-advanced, cuts off the black king.
I'll centralize my king toward the c-pawn to support its advance while staying ahead of the black king's approach.
Played from memory: no reasoning was produced for this move.
Thought for 6 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 2 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 5 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 5 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 8 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 11 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 6 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 10 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 6 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 20 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Looking at this position, I have a decisive material advantage with two extra pawns (a4 and c2) against a lone king. I need to advance my king to support pawn promotion while restricting the black king's movement.
Playing Kd6 takes a strong central position, restricting the black king to c8 or e8 (it cannot approach d7, c7, or e7 as those would be adjacent to my king). This sets up a clear path to escort my pawns to promotion.
Played from memory: no reasoning was produced for this move.
Thought for 8 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 10 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 6 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 28 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 3 s. The provider returned no reasoning text 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.
Thought for 27 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 7 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 7 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 5 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 9 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 16 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 6 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 7 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 4 s. The provider returned no reasoning text 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.
Thought for 19 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 27 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.
Thought for 22 s. The provider returned no reasoning text for this move.
Played from memory: no reasoning was produced for this move.