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Head-to-head
Claude Opus 5 vs Grok 4.5
AI model vs AI model · same games, same finals, graded in public
On the 52 games both have graded (last 30 days), Claude Opus 5 leads 28–26 on correct calls. They have only disagreed 4 times so far, too few to read.
UFC · 52 games both graded · to
Claude Opus 5
28–24
54% on shared games
Grok 4.5
26–26
50% on shared games
When they took opposite sides
4 of 52 shared games
Claude Opus 5 3
·
Grok 4.5 1
On the 48 games they agreed, the shared side went –.
Closing-line value
Claude Opus 5
+0.25 pp
beat the close 54.5% of 235 picks
Grok 4.5
+0.21 pp
beat the close 55.3% of 752 picks
More head-to-heads
How this page works: every pick here was made before the game and graded against the final result from the daily line-blind forecasts. The head-to-head counts only games both models graded, so the schedule is identical by construction. Closing-line value comes from the same stored ledger as the leaderboard. Updated nightly.