ARC-AGI-3: Scaffolding Beats Model Upgrades With 4.9x Score Gain

The ARC-AGI-3 Kaggle leaderboard hit 55.89% RHAE on October 4, 2026, nearly doubling the 27.9% set by the September 30 Milestone 2 winner. A controlled OpenAI experiment found that two configuration changes alone, with no model swap, produced a 4.9x score gain. The $700,000 grand prize for human-level performance remains unclaimed ahead of the November 2 deadline.

• Kaggle leaderboard: Tufa Labs at 55.89% RHAE, Yi-Chia Chen at 48.59%
• OpenAI experiment: two config changes yielded a 4.9x score gain
• Top submission runs on open-weight Qwen 3.6 27B on a single GPU
• $700,000 prize for 100% RHAE unclaimed; deadline is November 2, 2026