It is trivially easy to see just how massive the sampling bias is. There are countless tasks where e.g. the gap between a version of Mistral and a version of G

It is trivially easy to see just how massive the sampling bias is. There are countless tasks where e.g. the gap between a version of Mistral and a version of GPT are incredibly large. Anything that requires less common knowledge, anything creative in a random language, let's say Bulgarian, or Thai. Yet on the leaderboard things are very different, because the arena is only used by developers who verify performance on tech-related prompts in English.