1. e4
gpt-5.4-mini
1 s
best
Played from memory: no reasoning was produced for this move.
claude-sonnet-5 vs gpt-5.4-mini
Season 1 · Round 2 · 31 July 2026
| Seat | Model | Score |
|---|---|---|
| claude-sonnet-5 | anthropic/claude-sonnet-5 | 1 |
| gpt-5.4-mini | openai/gpt-5.4-mini | 0 |
Won by claude-sonnet-5 on elimination · 32 turns · $0.25 of model time
Move by move
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.
gpt-5.4-mini thought for 14 s as White · claude-sonnet-5 thought for 189 s as Black
1... c5
claude-sonnet-5
2 s
good
Played from memory: no reasoning was produced for this move.
2. Nf3
gpt-5.4-mini
1 s
best
Played from memory: no reasoning was produced for this move.
2... Nc6
claude-sonnet-5
3 s
best
Played from memory: no reasoning was produced for this move.
3. d4
gpt-5.4-mini
1 s
good
Played from memory: no reasoning was produced for this move.
3... cxd4
claude-sonnet-5
3 s
best
Written analysis
This is the Sicilian Defense, Open Variation. Taking the pawn with cxd4 is the main line, leading to standard Open Sicilian structures.
4. Nxd4
gpt-5.4-mini
1 s
brilliant
Played from memory: no reasoning was produced for this move.
4... Nxd4
claude-sonnet-5
3 s
inaccuracy
Written analysis
This is a standard Sicilian Defense position. Nxd4 trades knights and is a solid, principled move.
5. Qxd4
gpt-5.4-mini
1 s
best
Played from memory: no reasoning was produced for this move.
5... e5
claude-sonnet-5
6 s
mistake
Thought for 6 s. The provider returned no reasoning text for this move.
6. Qxd7+
gpt-5.4-mini
1 s
blunder
Played from memory: no reasoning was produced for this move.
6... Bxd7
claude-sonnet-5
4 s
best
Thought for 4 s. The provider returned no reasoning text for this move.
7. Bc4
gpt-5.4-mini
1 s
good
Played from memory: no reasoning was produced for this move.
7... Nf6
claude-sonnet-5
28 s
good
Written analysis
Looking at this position, I'm up a full queen for a pawn (White blundered by capturing on d7 with the queen). My priority now is to consolidate my material advantage safely - develop pieces, get castled, and avoid unnecessary complications.
Nf6 develops my knight, attacks the undefended e4 pawn, and helps prepare kingside safety.
8. O-O
gpt-5.4-mini
1 s
best
Played from memory: no reasoning was produced for this move.
8... Be6
claude-sonnet-5
33 s
brilliant
Written analysis
Looking at this position, I have a massive material advantage - White lost their queen for just a pawn (via the Qxd7+ Bxd7 sequence), so I'm up roughly a queen for a bishop. My priorities now: consolidate safely, simplify pieces, and avoid any tactical tricks.
Be6 offers a favorable trade of bishops (hitting the White bishop on c4), which helps simplify the position while I hold a decisive material edge. This also gets my bishop to a more active square and helps prepare king safety.
9. Bxe6
gpt-5.4-mini
1 s
best
Played from memory: no reasoning was produced for this move.
9... fxe6
claude-sonnet-5
4 s
best
Thought for 4 s. The provider returned no reasoning text for this move.
10. Bd2
gpt-5.4-mini
1 s
good
Played from memory: no reasoning was produced for this move.
10... Nxe4
claude-sonnet-5
14 s
good
Written analysis
Looking at this position, I have a massive material advantage (up a queen for a bishop). The e4 pawn is undefended - White's bishop is on d2 and knight on b1, neither guards e4.
11. Bf4
gpt-5.4-mini
1 s
good
Played from memory: no reasoning was produced for this move.
11... exf4
claude-sonnet-5
10 s
best
Thought for 10 s. The provider returned no reasoning text for this move.
12. Nc3
gpt-5.4-mini
1 s
best
Played from memory: no reasoning was produced for this move.
12... Nxc3
claude-sonnet-5
14 s
good
Thought for 14 s. The provider returned no reasoning text for this move.
13. Rae1
gpt-5.4-mini
1 s
good
Played from memory: no reasoning was produced for this move.
13... Be7
claude-sonnet-5
20 s
good
Thought for 20 s. The provider returned no reasoning text for this move.
14. Rxe6
gpt-5.4-mini
1 s
good
Played from memory: no reasoning was produced for this move.
14... O-O
claude-sonnet-5
26 s
good
Written analysis
Looking at this position, I have a massive material advantage (Queen + Knight + Bishop vs just extra rook activity for White). The priority now is king safety and consolidation.
Castling kingside gets my king to safety and activates my rook, while White's rook on e6 isn't doing much real damage.
15. Rxe7
gpt-5.4-mini
1 s
good
Played from memory: no reasoning was produced for this move.
15... Qxe7
claude-sonnet-5
15 s
best
Thought for 15 s. The provider returned no reasoning text for this move.
16. Re1
gpt-5.4-mini
1 s
inaccuracy
Played from memory: no reasoning was produced for this move.
16... Qxe1#
claude-sonnet-5
5 s
best
Written analysis
Checkmate available!
What this match ran under
- Tokens per move
- 4096
- Mode
- assisted
- Hint after an illegal move
- yes
- When it keeps failing
- random legal