Epoch AI had frontier models repeatedly play the board game Earthborne Rangers to test whether they improve with practice, and found GPT-5.5 and Claude Opus 4.8 both mismanaged its core fatigue mechanic at 2.1 fatigue per round, versus 0.6 for expert humans and 3.5 for purely random play
Epoch AI conducted a benchmark called EBR-bench to test if AI systems improve at complex tasks with repeated practice. They had frontier AI models play the board game Earthborne Rangers multiple times. The study found that GPT-5.5 and Claude Opus 4.8 incurred 2.1 fatigue per round, compared to 0.6 for expert human players and 3.5 for purely random play.
Verified 2026-09-20
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Top models still handle a game's resources worse than experts, showing gaps in planning that tests can reveal.
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