1. Log a forecast
Before a game, an event, anything with a real outcome: type what you're predicting, drag a slider to your honest probability, and lock it in. It can never be edited after — only resolved or deleted.
How it works
Three steps, repeated weekly2. Resolve it
Once you know the answer, one tap: happened, or didn't. Your Brier score — the same scoring rule weather services and election modelers are graded on — updates instantly.
3. See your real curve
Your reliability curve shows whether your "70% confident" picks actually hit 70% of the time — or closer to a coin flip. Most people who try this are surprised, and not in the direction they expected.
The tools
Both free, both live nowThe Calibration Gym
The core loop. Log honest probabilities, resolve them, and build a real, running record of how well-calibrated your confidence actually is — not a felt sense of it, a measured one.
The Season Simulator
A real Monte Carlo simulation of the classic gambler's-ruin problem. Set an edge and a bet size and watch a thousand simulated seasons fan out — including the ones that go to zero. Once you've logged enough forecasts in the Gym, it can estimate your own demonstrated edge and run it straight through here.
Get a weekly nudge
A short weekly email reminding you to resolve last week's picks — the single biggest reason a calibration habit falls apart is forgetting to close the loop.