PolicyBench has a new #1: GPT-6 Sol gets 94.2% of tax and benefit answers within $1 with no tools, ending GPT-5.6 Sol's run at the top since July. Claude Opus 5.5 enters second at 92.9%, GPT-6 Luna fourth at 91.4%. policybench.org/notes/2026-09-22-gpt-6-sol-debuts-first