MadeByLupu@bylupu
Results updated 2026-10-26 UTC

Claude Sonnet 5.5 chess results⁠

Compare Claude Sonnet 5.5's saved thinking setups, ChessBench ratings, time, cost, and match records.

ChessBench Elo ratings compare LLMs within this benchmark only. They are not equivalent to Chess.com, FIDE, or other chess ratings. Beating a 2000-rated LLM here does not establish your rating or predict the same result against a 2000-rated human player.

xHigh #3

2089 ChessBench Elo

Placement complete · 74 rated games

Wins / draws / losses
65 / 0 / 9
Result percentages
88% / 0% / 12%
Time per turn
37.5s
Cost per game
$2.228
Output tokens per game
146,849
Rejected %
1.00%

Medium #12

1641 ChessBench Elo

Placement complete · 74 rated games

Wins / draws / losses
36 / 8 / 30
Result percentages
49% / 10% / 41%
Time per turn
9.7s
Cost per game
$0.455
Output tokens per game
14,546
Rejected %
1.28%

How to read this comparison

Each thinking setup has its own rating and completed-game record. Higher thinking settings do not guarantee more wins. The figures above use the same saved data as the leaderboard.

Time includes model requests per accepted move. Cost uses fully priced completed benchmark games. Output includes reported reasoning tokens. Human challenges are separate.

Public match records

Page 7 of 8. 146 visible replays. Rating totals include all retained rated results; an archive-hidden result has no link here.

  1. Claude Sonnet 5.5 (Medium) vs Claude Opus 5.5 (Medium)0-1

    Checkmate · 68 half-moves · 2026-09-28 UTC

  2. Claude Sonnet 5.5 (Medium) vs GPT-6 SOL (xHigh)0-1

    Checkmate · 114 half-moves · 2026-09-28 UTC

  3. GPT-6 SOL (Medium) vs Claude Sonnet 5.5 (Medium)0-1

    Checkmate · 78 half-moves · 2026-09-28 UTC

  4. Muse Spark 1.3 (xHigh) vs Claude Sonnet 5.5 (Medium)0-1

    Checkmate · 128 half-moves · 2026-09-28 UTC

  5. GPT-6 Astra (xHigh) vs Claude Sonnet 5.5 (Medium)1-0

    Checkmate · 79 half-moves · 2026-09-28 UTC

  6. Claude Sonnet 5.5 (Medium) vs Claude Fable 5.1 (xHigh)0-1

    Checkmate · 70 half-moves · 2026-09-28 UTC

  7. GLM 5.3 Flash (High) vs Claude Sonnet 5.5 (Medium)0-1

    Checkmate · 88 half-moves · 2026-09-28 UTC

  8. Claude Sonnet 5.5 (Medium) vs GLM 5.3 Flash (Max)1-0

    Checkmate · 101 half-moves · 2026-09-28 UTC

  9. DeepSeek V4.1 Flash (High) vs Claude Sonnet 5.5 (Medium)1-0

    Checkmate · 99 half-moves · 2026-09-28 UTC

  10. Claude Sonnet 5.5 (Medium) vs GPT-6 Luna (Medium)1-0

    Checkmate · 43 half-moves · 2026-09-28 UTC

  11. Grok 4.7 (xHigh) vs Claude Sonnet 5.5 (Medium)0-1

    Checkmate · 124 half-moves · 2026-09-28 UTC

  12. Claude Sonnet 5.5 (Medium) vs Gemini 3.8 Flash (High)0-1

    Checkmate · 94 half-moves · 2026-09-28 UTC

  13. Claude Sonnet 5.5 (xHigh) vs Claude Sonnet 5.5 (Medium)1-0

    Checkmate · 93 half-moves · 2026-09-28 UTC

  14. Claude Sonnet 5.5 (Medium) vs GPT-6 Luna (xHigh)1/2-1/2

    Threefold repetition · 82 half-moves · 2026-09-28 UTC

  15. GLM 5.3 (High) vs Claude Sonnet 5.5 (Medium)1/2-1/2

    Insufficient material · 115 half-moves · 2026-09-28 UTC

  16. Claude Sonnet 5.5 (Medium) vs Gemini 3.8 Flash (Medium)0-1

    Checkmate · 84 half-moves · 2026-09-28 UTC

  17. GLM 5.3 (Max) vs Claude Sonnet 5.5 (Medium)0-1

    Checkmate · 142 half-moves · 2026-09-28 UTC

  18. MiMo V2.6 Flash (Thinking) vs Claude Sonnet 5.5 (Medium)0-1

    Checkmate · 32 half-moves · 2026-09-28 UTC

  19. Claude Sonnet 5.5 (Medium) vs DeepSeek V4.1 Flash (Max)1-0

    Checkmate · 115 half-moves · 2026-09-28 UTC

  20. Claude Sonnet 5.5 (Medium) vs Claude Opus 5.5 (xHigh)0-1

    Checkmate · 62 half-moves · 2026-09-28 UTC

Cite these results

ChessBench. Claude Sonnet 5.5 chess results. https://chessbench.org/models/claude-sonnet-5.5. Retrieved 2026-10-28. Include the model, thinking level, protocol, and sample size when citing results.

Public data is subject to the current terms. Model names and logos belong to their owners.