Metric · LLM analytics

What is eval pass rate, and how do you track it in Metabase?

Definition

Eval pass rate is the share of evaluation examples that pass their scorer's threshold in a run — the closest thing LLM development has to a test-suite green rate. Tracked over time on stable datasets and scorers, it turns 'the new prompt feels better' into a measured claim, and its per-scorer breakdown shows exactly which quality dimension moved.

Formula: COUNT(passed) ÷ COUNT(examples) per experiment — comparable only within the same dataset version and scorer set

What data do you need?

  • Eval results at example grain: experiment, dataset, scorer, score, pass flag, created-at
  • Experiment metadata: model, prompt version, cost
  • Dataset and scorer version columns — the comparability keys
  • Online eval scores from production samples, where run, in the same vocabulary

SQL pattern

Pass rate by experiment with per-scorer breakdownPostgreSQL
SELECT
  experiment,
  scorer,
  MIN(created_at) AS run_at,
  COUNT(*) AS examples,
  ROUND(
    100.0 * COUNT(*) FILTER (WHERE passed) / NULLIF(COUNT(*), 0), 1
  ) AS pass_rate_pct,
  ROUND(AVG(score), 3) AS mean_score
FROM eval_results
GROUP BY experiment, scorer
ORDER BY run_at, scorer;

Common pitfalls

Comparing pass rates across different datasets.→ 90% on an easy dataset and 60% on a hard one say nothing relative to each other. Trend each dataset separately and version datasets when they change.
Changing scorers mid-history.→ An LLM-as-judge prompt tweak shifts every score after it. Version scorers, store the version as a column, and break trend lines at version boundaries.
Watching only the aggregate.→ Scorers can move in opposite directions and net to zero. Keep the per-scorer table, and rank regressed examples by score delta — pass/fail flips lag the drift.
Treating offline pass rate as production quality.→ A dataset covers what you thought to test. Sample production traffic with online evals and report coverage — the share of real usage the evals exercise — next to the rate.

Where does this metric apply?

This metric commonly uses data from Braintrust experiments, LangSmith experiments and datasets, Arize Phoenix evals, W&B Weave evaluations, plus any warehouse models that provide the same grain of LLM usage data.

Dashboards

Integrations

Metrics

Analytics

FAQ

How do you track eval pass rate in Metabase?
Export example-grain eval results from tools like Braintrust, LangSmith, or Phoenix into a warehouse table with experiment, dataset, scorer, score, and pass columns. Chart pass rate per experiment ordered by run time, per dataset — the eval quality dashboard adds the regression and model-comparison views.
What's a good eval pass rate?
Whatever threshold you've decided is shippable for that dataset — pass rates are self-referential, since you set both the scorers and the bar. The valuable signals are relative: is the rate improving run over run, did the candidate model beat the incumbent on the same dataset, and did any scorer regress even while the aggregate rose.
Pass rate or mean score — which should I trend?
Both, for different jobs. Pass rate against a fixed threshold is the ship/no-ship signal and survives scorer scale quirks; mean score shows movement within the passing band, which is where regressions gather before they flip flags. The regression table should rank by score delta for exactly that reason.