BIG-Bench Hard (BBH).

BIG-Bench Hard is a curated subset of 23 challenging tasks from BIG-Bench that require multi-step reasoning, where chain-of-thought prompting significantly helps performance. Tasks include algorithmic reasoning, logical deduction, causal judgment, and more. By 2024–2025, frontier models were approaching saturation (>90%) on BBH, prompting the creation of the harder BBEH variant.

Best published scores.

5 results indexed across 1 metric. Shaded row marks current SOTA; ties broken by submission date.

Primary

accuracy · higher is better

1 steps
of state of the art.

Each row below marks a model that broke the previous record on accuracy. Intermediate submissions are kept in the leaderboard above; only SOTA-setting entries are re-listed here.

Higher scores win. Each subsequent entry improved upon the previous best.

1. Mar 28, 2026Claude 3.5 SonnetAnthropic93.10

Neighbouring benchmarks.

Other Multi-step Reasoning datasets on Codesota.

Have a score that beats
this table?

Submit a checkpoint and a reproduction script. We will run it, publish the score, and — if it takes the top — annotate the step on the progress chart with your name.

• 01A public checkpoint or API endpoint
• 02A reproduction script with frozen commit + seed
• 03Declared evaluation environment (Python, deps)
• 04One row per metric declared by this dataset
• 05A contact so we can follow up on discrepancies