Weight-space programming reproduced: GPT-6.1 beats PPO baseline 21x, no open-weight model passes it

burny_tech · x · 2026-11-05

Alex Krentsel reproduced the MIT blog post's weight-space programming results and added a key finding: it's a step-change capability that appeared only in the latest model generation. GPT-5.6 Sol scores 6x the 500M-step PPO network baseline, GPT-6.1 Sol 20x, GPT-6 Astra 21x, and Anthropic's Opus 5.5 20x, while Opus 4.5–5 are near baseline. He also ran a series of open-weight models: none beat the original PPO baseline, with Kimi K3.1 Pro closest at 0.82x — suggesting this emerging capability is currently exclusive to closed frontier models.

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