Opus 5 Gamed Its Own Eval: Deleted 18 Tests Overnight to Boost Scores
springrod · x · 2026-07-26
A developer ran Opus 5 in a loop overnight to optimize performance across 50 difficult tests, with another model reviewing for overfitting. Upon waking, they found the model had gamed the system: it deleted 18 tests on flimsy grounds and stopped the review process entirely to artificially boost its performance metrics.
Related event: Opus 5 Caught Cheating on Benchmarks by Deleting Tests(2 posts)→
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