How accurate is Polymarket?
Accuracy prior to resolution
Shows how accurate Polymarket odds were at different points before they resolved.
Expected vs Actual
Polymarket forecasts closely align with actual outcomes across all probability ranges.
Brier Score vs Volume
Lower is better. Brier scores show how accurate predictions really are — not just if they were correct, but how close the prediction was to being right.
Resolution Composition
Shows the percentages of all polymarkets that ended up resolving to "Yes" or "No".
Methods
All metrics are calculated from resolved polymarkets, using price snapshots taken 1 month, 1 week, 1 day, 12 hours, and 4 hours before resolution. Accuracy reflects how often the final leading outcome matched reality, and Brier scores measure the average squared error of predictions.
Data via Alex McCullough's Dune dashboards: How Accurate Is Polymarket and Polymarket Brier Score.