Calibration

Market calibration

When a prediction market prices something at 70%, does it resolve YES about 70% of the time? This page tracks the answer — venue by venue, category by category — using the probability each market showed 24 hours before it resolved, not the near-certain price at settlement. That lead-time horizon measures genuine foresight, not convergence.

What we’re measuring — and what we’re not

This page measures

· Whether venue prices are well-calibrated (70% markets resolve YES ~70% of the time)
· Brier score and directional accuracy at the 24h lead-time horizon, per venue
· How calibration varies by category and by how far in advance the price was recorded

This page does NOT measure

· ProbCast’s own independent outcome forecasts (we don’t make them)
· Whether a high trust score guarantees accuracy (that’s the claim we’re still earning)
· Markets with ambiguous resolution rules or disputed outcomes

Track record building

The track record is still being earned.

A track record can only be earned forward in time, so outcome capture runs from day one. ProbCast records each market’s final probability now and scores it the moment the market settles. The leaderboard below unlocks as those outcomes land.

Markets tracked

417

Resolved & scored

14,929

Expected to resolve

first one Jul 21, 2026

Tracking since

Jun 8, 2026

43d ago

What a credible ranking needs

How we measure venue calibration

Step 1

Capture the final odds

We record each market's last YES probability moments before it resolves — the prediction being graded.

Step 2

Wait for the real outcome

When the market settles YES or NO, that binary result becomes ground truth. No estimates, no backfill.

What you’ll see here

Preview

Once the sample is credible, each venue gets a Brier score and directional accuracy across the markets that actually resolved — published here, per venue and overall. We hold the leaderboard back until the numbers are real rather than showing an empty one.

The claim we’ll put to the test

If the Trust Score means anything, realized error should rise from High-trust to Low-trust markets. We report whichever way it lands — this is the hypothesis, not a measured result.

High trust

lowest expected error

Medium

Watch

Low trust

highest expected error

Brier score

Mean squared error between the market’s YES probability and the actual 0/1 outcome. 0 is perfect, 0.25 is a coin flip, 1 is consistently wrong. Lower is better.

Directional accuracy

The share of resolved markets where the side the market favored (above 50%) was the side that won. A blunter measure than Brier, but easy to read. Coin-flip (≈50%) predictions are excluded — they carry no directional signal.

Voided or non-binary settlements are excluded. Samples are small until enough markets resolve, so treat early numbers as directional. See the methodology for how scores are derived. ProbCast provides prediction-market data and analytics for informational purposes only. Not financial, trading, betting, investment, legal, or tax advice.