Expanding BigLaw Bench

This post details the expansion of the BigLaw Bench (BLB) benchmark to include global jurisdictions, core legal practice areas (UK, Australia, Spain, Capital Markets, M&A, Fund Formation, Litigation, Arbitration, IP), and complex legal research tasks. It reflects on learnings from the original BLB, emphasizing task performance as the most accurate measure of model capabilities and discussing how BLB is used to understand general model gaps (e.g., distinguishing evidentiary rules) and test model behaviors (e.g., sycophancy). The post previews methodological deep dives into each new benchmark area and announces upcoming updated BLB scores for major models.