Lao Guo's Learning Space

Oct 29, 2026 · Artificial Intelligence

Two Top LLM Leaderboards Disagree on #1: Private Tests & 12-Point Open-Source Gap

This analysis compares three major LLM benchmarks—LMArena, Artificial Analysis Intelligence Index v5, and SWE-bench—revealing why they crown different winners, how a 60% shift to private test sets exposes data contamination, why open-source models now trail closed-source by 12 points, and how to choose models based on task, budget, and deployment constraints.