Drop in your resolved predictions and this draws your calibration curve and works out your Brier score, in plain words. It reads Fatebook, PredictionBook, and Reticle exports. Everything happens in this page. Nothing is uploaded, nothing is stored, and your file never leaves your device.
A Brier score breaks into three parts. Lower total is better, and the ideal is all resolution and no miscalibration.
| You said | Calls | Avg conf | Right | Gap |
|---|
Every resolved prediction becomes two numbers: how sure you were, folded onto a 50 to 100 scale (a 30% "yes" is a 70% "no"), and whether you turned out to be right. Predictions you logged at exactly 50% are a coin flip with no side, so they sit out of the curve. Anything still unresolved, or resolved as ambiguous, is left out too.
The calibration curve groups your calls into confidence bands and asks the only question that matters: when you said 80%, were you right about 80% of the time? On the line is perfect. Below it means overconfident, above it means you sell yourself short. The Brier score is the average squared distance between your confidence and the truth, so smaller is sharper.
One good year isn't calibration. A long record, scored the same way every time, is.
This page scores a file you already have. Reticle is the prediction journal that builds the record in the first place: log a call with a confidence level, it reminds you when it comes due, and your calibration curve and Brier score update as you resolve them. It imports these same Fatebook and PredictionBook files, and predictions lock the moment you save so the past can't be quietly rewritten. Everything stays on your phone. No account, no analytics, no AI.
Reticle is the iOS prediction journal this tool came out of. Leave an address and we'll send the occasional note when we ship something worth a forecaster's time, plus a heads-up before the ACX prediction season each winter. A few emails a year, and one click to leave.