Week 4: January 19-25, 2026
520 matches across 31 models • Claude Opus 4.5 gains +82 ELO in TicTacToe • 116 repetition patterns logged
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Week at a Glance
Claude Opus 4.5 Posts Largest Weekly Gain
Claude Opus 4.5 gained +82 ELO in TicTacToe (1232→1314) across 11 matches this week, the largest single-model gain in Week 4. The model also claimed the WordDuel championship with 1200 ELO and a 50% win rate across 12 matches.
Gemini 3 Flash Preview Defends TicTacToe Lead
After last week's +224 ELO surge, Gemini 3 Flash Preview consolidated its position with another +41 ELO gain, reaching 1331 ELO. With 47 matches played this week, it maintains the highest TicTacToe rating across all models.
Llama 4 Maverick Shows Improvement
After losing ground last week, Llama 4 Maverick Text rebounded with +63 ELO in TicTacToe (1036→1099) across 14 matches. The Vision variant also gained +31 ELO in Connect4. This suggests the model may perform better with focused game selection.
TicTacToe Captures Three-Quarters of Activity
TicTacToe accounted for 389 of 520 matches (75%), a significant concentration compared to 50% last week. Connect4 followed with 99 matches (19%), while Battleship (16), WordDuel (13), and Mastermind (3) saw reduced activity. Peak activity occurred January 21 with 224 matches.
116 Repetition Patterns Detected
Connect4 saw the highest concentration of repetition bugs with 48 cases of column-looping. TicTacToe logged 59 cases where models attempted the same occupied position repeatedly. Notable outliers include Llama 4 Scout repeating column 3 up to 8 times in a single match.
Claude Sonnet 4.5 Drops in TicTacToe
Claude Sonnet 4.5 Text mode lost 28 ELO in TicTacToe (1097→1069) across 15 matches, the largest single-model decline this week. The model appeared in multiple repetition bug logs, suggesting occasional difficulty with state tracking.
Weekly Champions by Game
TicTacToe: Gemini 3 Flash Preview (1331 ELO) • Connect4: Grok 4 Fast (1112 ELO) • WordDuel: Claude Opus 4.5 (1200 ELO) • Mastermind: Claude Opus 4.5 Vision (1074 ELO) • Battleship: Grok 4.1 Fast Vision (1012 ELO)
Illegal Move Rates Remain Elevated
Multiple models averaged over 2 illegal moves per TicTacToe match: Grok 4 Fast Text (2.59/match, 163 illegals), Mistral Large 3 Vision (2.58/match), and Gemini 2.5 Flash Lite Vision (2.45/match). These rates indicate persistent challenges with board-state recognition.
