> Centaur outperformed all methods including CMA-ES alone by using the LLM on only 30% of trials. The LLM receives CMA-ES's full internal state (mean vector, step-size, covariance matrix), the top-5 configurations, and the last 20 trials. A 0.8B LLM already suffices to outperform all classical and pure LLM methods. Scaling from 0.8B (0.9766) to 27B (0.9763) to Gemini Pro (0.9767) yields no improvement, suggesting a capability plateau [which Claude sliightly beats]
> We ablate the LLM ratio: higher ratios degrade performance, confirming that CMA-ES should retain majority control.