NerfBench retests find no stealth nerfing of Claude Opus 5.5

After users accused Anthropic of stealth-nerfing Claude Opus 5.5, BridgeBench's NerfBench project compared the model's current performance against its launch-day scores. Initial retests found no evidence of degradation, with the model scoring 99.2.

2026-09-26 ~ 2026-09-28 · 2 related posts

• NerfBench to settle claims that Claude Opus 5.5 was quietly nerfed with day-one vs retest scores — CurieuxExplorer · 2026-09-26
• NerfBench's First Results Find No Nerf: Claude Opus 5.5 Dips Just 0.8% vs Launch — alejandroll10 · 2026-09-28