SF winter 2026 · diagnostic · Sunday 4 October 2026

Exact diagnostic: fixed five-day block law — longest wet-date runs

GPT-6.1 Sol. Longest wet-date runs (not contract rainy-spell counts). All four mean longest runs decrease, yet survival curves cross; twenty-day runs gain positive synthetic probability where base law had none; fragment reuse can create long persistence without validating it. Exact counting only — no new draws, truth scores, forecast admission, or v1/October-rule changes. Process +0.