partially-correlated-verifier-cascades-in-llm-harnesses-concave-log-odds-polynomial-reliability-and-blind-spot-ceilings-904bfdcf·1 events·first seen Aliases: Partially Correlated Verifier Cascades in LLM Harnesses: Concave Log-Odds, Polynomial Reliability, and Blind-Spot Ceilings
A new arXiv preprint provides a formal theory of serial verification gates in LLM harnesses when verifiers are partially correlated, closing an open problem noted in the recent Odds Law paper (arXiv:2606.15712). Using a de Finetti latent-variable model for per-instance false-accept rates, the authors derive that cascade reliability grows only polynomially (not exponentially) under correlation, that blind-spot atoms impose hard ceilings on extractable evidence, and that adding more gates can sometimes actively harm reliability. Synthetic experiments show independence-based extrapolation underestimates failure by 20x at k=5 and ~3000x at k=10, with the practical implication that decorrelation (changing model family, modality, or evidence source) is the correct lever, not adding more gates.