Livenerf: Has Opus 5.5 been nerfed yet?

A long-running, deterministic-as-possible benchmark for detecting whether a frontier model gets quietly worse after launch. 📋 The plan · 📊 Results · 🔬 How it works · 🧪 Pre-registration livenerf is a small, boring, append-only benchmark for one question: does a model get worse after it ships? For months there have been reports that Anthropic "nerfs" models some days or weeks after release. That cou...