How it works
Predicta is not a crystal ball. It is a classic statistical model adapted to football, and every step can be explained simply. Here is what happens when you ask for an estimate.
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1. Fetch the matches
The app asks the Predicta server for both teams’ latest results and the league’s average goals. The data comes from a football data API; the access key stays on the server and is never in the app.
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2. Measure attack and defense
For each team, goals scored and conceded are compared with the league average. A team that scores more than average has a strong attack; a team that concedes less has a solid defense.
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3. Give more weight to recent games
A match played last week says more about current form than one from three months ago. Each older match therefore counts slightly less than the next one.
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4. Avoid extreme values
With few matches, an exceptional run can be misleading. The model therefore pulls values toward the average, more strongly the smaller the sample.
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5. Account for the venue
Home advantage is not a fixed bonus: it is derived from the average goals actually observed at home and away in the league.
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6. Calculate the probabilities
Each team’s expected goals feed a Poisson distribution. From it we derive the probability of each scoreline, then of a win, a draw and a defeat. A Dixon-Coles correction adjusts low scores (0-0, 1-0, 0-1, 1-1), which a simple model describes poorly.
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7. Head-to-head meetings
If you choose this basis, matches between the two teams are blended with their current form. They are never used on their own: the sample is too small and squads change.
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8. Check afterwards
Once the match has been played, the app compares the estimate with the final score. The main measure is the correct outcome (win, draw or defeat); the exact score is a secondary measure, and a much harder one.
What the model doesn’t know
- Injuries, suspensions and team line-ups are not taken into account.
- Motivation, weather, managerial changes and what is at stake in the match are not modeled.
- Few available matches (early season, newly promoted team) make the estimate less reliable.
- A 60% probability means the event fails to happen four times out of ten: it does happen regularly.