serialization

Solve AUC@2

Attempt-adjusted solve rate: first-try solve = 1.0, second-attempt-only = 0.5.

Formula: (pass_at_1 + pass_at_n) / 2 = (2·tasks_passed_attempt_1 + tasks_passed_attempt_2_only) / (2·task_set_size)

Primary ranking metric. Rewards first-try correctness over fail-then-repair without ignoring the two-attempt protocol. De-saturates the headline that pass_at_n compresses. Significance via paired bootstrap (tier bands), not Wilson.

First-try pass rate

Tasks solved on the first attempt / tasks in scope (strict).

Formula: tasks_passed_attempt_1 / task_set_size

Measures single-shot accuracy without retry credit. Useful when comparing models where the second attempt is not available.

Avg cost / task

Average LLM cost per distinct benchmark task in USD.

Formula: SUM(cost_usd) / COUNT(DISTINCT task_id) across all the model's results in scope.

Use to compare operating cost across models with similar pass rates. Does not account for quality. Combine with $/Pass for a cost-efficiency view.

$/Pass

Total cost divided by number of distinct tasks passed. Lower is better.

Formula: SUM(cost_usd) / tasks_passed_distinct across all runs.

Best single cost-efficiency metric. Penalises expensive models that pass few tasks and rewards cheap models with high pass rates.

Latency p95

95th-percentile per-task wall time. Captures tail latency.

Formula: 95th percentile of per-task duration_ms across all tasks in all runs.

Use p95 to understand worst-case latency. A low p95 means the model rarely stalls, relevant for automated pipelines with timeouts.