How do I simulate a curling stone?

Open this page and use the live Pythagorean Expectation tool below — set your inputs and the simulation runs instantly in your browser using real numerics. No install, no account needed.

Yes. The simulation runs free in your browser. A one-time unlock or a Pro plan adds advanced parameters, saved presets, data import, and clean exports.

Can I use my own numbers?

Absolutely — every input is adjustable, and with data import you can drive a curling stone from your own measurements.

Use case · powered by Pythagorean Expectation

Pythagorean Expectation for a curling stone

Simulate a curling stone live in your browser. This runs the real Pythagorean Expectation solver — adjust the inputs, watch it respond instantly, and export the result. No install, no account.

For:Students Researchers Educators Engineers Hobbyists & Makers K-12 Students First Responders

Pythagorean ExpectationLive

wins from points

Controls

Presets

Points/runs scored

Points/runs allowed

Bill James discovered that a team's win percentage tracks the ratio of points scored to points allowed, raised to a sport-specific exponent — the Pythagorean expectation. It predicts records better than actual wins early in a season, exposing teams that are lucky or unlucky and due to regress. The exponent varies from ~1.8 in baseball to ~14 in basketball.

▶ Run in Python

Data Inspector

Expected win %53.2%

Projected wins86 of 162

Exponent1.83

Governing equation

Win% = \frac{75 0 ^{1.83}}{75 0 ^{1.83} + 70 0 ^{1.83}} = 53.2%

Reading this result: A near-even scoring ratio lands close to .500 (53.2%); with an exponent of 1.83, Baseball win % swings sharply once the ratio tilts.

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

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About this simulation

The full Pythagorean Expectation tool models a curling stone with the same numerics engineers and scientists use — running entirely client-side. Change any parameter and the result updates in real time, so you can build intuition, check a design, or teach the concept without spreadsheets or installs.

More you can do with Pythagorean Expectation

Pythagorean Expectation for a basketball free throw Pythagorean Expectation for a soccer penalty Pythagorean Expectation for a baseball pitch Pythagorean Expectation for a golf putt Pythagorean Expectation for a tennis serve Pythagorean Expectation for a football field goal Pythagorean Expectation for a sprint race Pythagorean Expectation for a marathon pace

Other ways to simulate a curling stone

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Frequently asked questions

How do I simulate a curling stone?: Open this page and use the live Pythagorean Expectation tool below — set your inputs and the simulation runs instantly in your browser using real numerics. No install, no account needed.
Is it free?: Yes. The simulation runs free in your browser. A one-time unlock or a Pro plan adds advanced parameters, saved presets, data import, and clean exports.
Can I use my own numbers?: Absolutely — every input is adjustable, and with data import you can drive a curling stone from your own measurements.