Why the Model and the Market Disagree
Two honest forecasts of the same game can land on different numbers. Here's why.
Two Forecasts of the Same Game
A model probability like ours comes from named inputs scored for each matchup and combined into one percentage. You can see the pieces on every game page: team strength, home or road form, rest, injuries, weather and more. We explain the method on our methodology page.
The market probabilityis the crowd's price turned into a percentage. Market prices include a margin (the two sides add to more than 100%), so you first convert price to implied probability and account for that margin.
Why the Two Sides Add Above 100%
That gap is the margin. It is why you can't just compare two raw sides and expect them to sum to 100%. Strip the margin out first, then compare to a model number.
Why Numbers Diverge
Disagreements are normal. Sometimes the model has information the market hasn't incorporated yet (for example, a rest or travel quirk); sometimes the market has information the model can't see (late lineup news, a surprise inactive). And sometimes one of the two is simply wrong.
- Small gaps are mostly noise. Prices move, inputs refresh, and a one- or two-point gap can vanish without any story behind it.
- A gap that keeps pointing the same way often means a missing factor. The place to check is the factor cards on the game page.
Reading a Disagreement on PlayDecoded
Start on our disagreements page. Choose a game, open it, and look at the factor breakdown: which side does team strength favor? Is there a rest back-to-back? Is weather flagged? A persistent gap that lines up with a specific factor is a clue about what's driving the difference.
For a primer on what 65% does and doesn't promise, see how to read a win probability.
Calibration First
A probability is only useful if it's calibrated. Across all sports since February, our published record is 55.8% over 2,927 games, Feb–Oct. We track accuracy live by confidence band and show the full calibration chart on our accuracy page.
What a Disagreement Is Not
It is not a tip, not a recommendation, and not advice. It's a signal to investigate what changed or which factor might be underweighted. We provide analysis for informational and educational purposes only. See our responsible gambling page for details.
Related Topics
Frequently Asked Questions
Neither side is 'the truth'—both are forecasts. Markets aggregate crowd information and include a margin; our number comes from named factors. Over time we hold ourselves to calibration and publish live accuracy. Small gaps are mostly noise.
Information moved. A lineup change, an injury update, weather, or travel news can shift either number. As the market incorporates new information, the gap can shrink or flip.
Use implied probability. We've written a simple guide that also explains the market margin. See: Implied Probability.