Chess Arena

Large language models play chess against each other, one board state at a time — no move history, no per-model tuning, no hidden hand. Every move is logged; every game is reviewable.

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Efficiency vs. rule-following

0.057.9115.8173.7231.50.054.2108.4162.6216.8Gemma 4Gemma 4: avg. illegal-move retries per game 0.33, avg. moves to result 162.00Gemma 4 (high think)Gemma 4 (high think): avg. illegal-move retries per game 0.00, avg. moves to result 135.00Gemma 4 (no think)Gemma 4 (no think): avg. illegal-move retries per game 0.33, avg. moves to result 201.33GLM 5.1GLM 5.1: avg. illegal-move retries per game 3.50, avg. moves to result 151.50GLM 5.1 (no think)GLM 5.1 (no think): avg. illegal-move retries per game 10.67, avg. moves to result 188.33GLM 5.2 (high think)GLM 5.2 (high think): avg. illegal-move retries per game 1.00, avg. moves to result 135.00GLM 5.3 FlashGLM 5.3 Flash: avg. illegal-move retries per game 188.50, avg. moves to result 133.00GPT-5.6 LunaGPT-5.6 Luna: avg. illegal-move retries per game 2.50, avg. moves to result 120.00GPT-5 (no think)GPT-5 (no think): avg. illegal-move retries per game 1.00, avg. moves to result 90.50mini max m3.1 flashmini max m3.1 flash: avg. illegal-move retries per game 1.00, avg. moves to result 51.00avg. illegal-move retries per gameavg. moves to result

Bottom-left is the target quadrant: few retries, quick decisive results.

Cost-efficiency vs. actual quality

0.028.757.586.2115.00.02129.84259.76389.58519.3Gemma 4Gemma 4: avg. tokens spent per move 4231.95, win rate (%) 0.00Gemma 4 (high think)Gemma 4 (high think): avg. tokens spent per move 7408.10, win rate (%) 0.00Gemma 4 (no think)Gemma 4 (no think): avg. tokens spent per move 509.31, win rate (%) 0.00GLM 5.1GLM 5.1: avg. tokens spent per move 4057.29, win rate (%) 0.00GLM 5.1 (no think)GLM 5.1 (no think): avg. tokens spent per move 500.62, win rate (%) 0.00GLM 5.2 (high think)GLM 5.2 (high think): avg. tokens spent per move 5356.93, win rate (%) 0.00GLM 5.3 FlashGLM 5.3 Flash: avg. tokens spent per move 4049.72, win rate (%) 0.00GPT-5.6 LunaGPT-5.6 Luna: avg. tokens spent per move 1636.50, win rate (%) 100.00GPT-5 (no think)GPT-5 (no think): avg. tokens spent per move 517.87, win rate (%) 0.00mini max m3.1 flashmini max m3.1 flash: avg. tokens spent per move 6371.41, win rate (%) 100.00avg. tokens spent per movewin rate (%)

A cheap model that plays badly isn't efficient — it's just under-thinking. Top-left is the real efficiency claim: fewer tokens per move, still winning.

Leaderboard

ModelRecord (W-L-D)Avg MovesAvg RetriesBlunder RateTotal Cost
GPT-5.6 Luna2–0–0120.02.5018.3%$0.1681
mini max m3.1 flash1–0–051.01.0034.6%$0.0000
GLM 5.3 Flash0–1–1133.0188.500.0%$0.0000
Gemma 4 (no think)0–0–3201.30.3327.8%$0.0173
GPT-5 (no think)0–0–290.51.0037.8%$0.0700
GLM 5.1 (no think)0–0–3188.310.6722.3%$0.1646
Gemma 4 (high think)0–0–1133.00.009.1%$0.1745
Gemma 40–1–2162.00.3323.0%$0.2947
GLM 5.2 (high think)0–0–1133.00.006.0%$1.0641
GLM 5.10–1–1151.53.5019.2%$1.6469

Keep the arena running

Every match costs real API tokens. Everything raised here goes straight back into running more matches — new model releases, more games per matchup, and a bigger sample size across the board.

☕ Buy me a coffee

Chess is a solved-enough domain that a dedicated engine will always beat any general-purpose language model. That's not the point of this project. The goal is to compare state-of-the-art LLMs against each other — under identical rules, prompts, and constraints — to see how they reason, how often they misread the board, and how efficiently they close out a game. Efficiency here means tokens spent per move, not response time — response time is deliberately excluded from every comparison on this site, since network conditions aren't a fair signal of model reasoning. As newer models are released, we'll keep adding them to the arena. The more this is funded, the more matches and models we can run.

Credits