EVL
BIG-Bench Hard
Hard reasoning tasks
What this measures
BIG-Bench Hard — 23 tricky tasks (logical deduction, date arithmetic, sarcasm detection, multi-step puzzles) where earlier models struggled. A grab-bag stress test of reasoning.
Sample
'If today is Wednesday and it was 3 days before yesterday, what day was it?' — plus 22 other puzzle types.
Leaderboard · 100 models
Average accuracy across the 23 tasks — higher is betterBenchmark health
headroomPlenty of room at the top — this benchmark still separates frontier models clearly.
63.4
top-10 mean
65.5
best
100
models
What improves this score
Datasets & environments shown to raise it.
Research using this benchmark
all →Orca: Progressive Learning from Complex Explanation Traces of GPT-4How Hard is it to Rig a Benchmark? A Social Choice Analysis of Leaderboard RobustnessThe Coupling Tax: How Shared Token Budgets Undermine Visible Chain-of-Thought Under Fixed Output LimitsPost Reasoning: Improving the Performance of Non-Thinking Models at No Cost
Matched by name in title/abstract.