Superintelligence Plots

On the Epoch Capabilities Index (ECI), the best closed-weight model (Claude Opus 5.5, 168.8) led the best open-weight model (Moonshot’s Kimi K3, 157.9) by 11.0 points on 2026-10-01, compared with an average gap of 5.9 points across 2024 and 2025 and 10.1 points so far in 2026. Kimi K3’s July release briefly cut the gap to 6.1 points before Claude Fable 5.1, GPT-6 Astra and Claude Opus 5.5 reopened it in September, so open-weight models are improving quickly but the closed frontier has moved faster this year. That is the bar facing Kimi K3.1 Pro, a post-trained successor to K3 whose strong self-reported coding and agent benchmarks SI News calls a notable new challenge to proprietary frontier models, with weights promised by November 4 and no ECI score yet.

Sources & Notes

• Original story: Kimi K3.1 Pro launches as a 3T-class open-weight model | OpenAI moves frontier training to offline environments
• Data sources: Epoch AI (2026). Epoch Capabilities Index (ECI) model scores
• Other references: Epoch AI (2026). Epoch Capabilities Index; Edwards, J., & Emberson, L (2026). Open models lag state-of-the-art closed models by 4 months; Moonshot AI (2026). Introducing Kimi K3.1 Pro
• Notes: Each point is the gap, on the first day of each month from 2024-01-01 to 2026-10-01, between the highest central ECI estimate among models in Epoch’s Closed weights group and the highest among models in its Open weights group (which includes restricted-use and non-commercial licenses; Kimi K3 is non-commercial) released on or before that date. Models Epoch classifies as Other (unknown or limited access, such as Gemini 4 Argon at 166.5) are excluded, and the gap was unchanged at 11.0 points on 2026-10-24. Data were downloaded on 2026-10-24 from the CSV Epoch updated that day; the confidence intervals for the current leaders span roughly 5 to 9 points and shift when Epoch refits the index, which is why Epoch’s May 2026 analysis reported an average gap of about 8 points since January 2026 while the current fit gives about 10.5 points for 2026-01-01 to 2026-05-29. Kimi K3.1 Pro’s benchmark results are self-reported by Moonshot AI and not yet in the ECI.