Over 2.5 goals means 3 or more total goals in the match. Under 2.5 means 2 or fewer. The Poisson model calculates this by summing probabilities for all scorelines with 3+ combined goals.
Over/Under 2.5 predictions are among the most accurate football betting markets, with typical model accuracy of 55-65%. The Poisson model performs best on goal-line markets because goal distribution follows a Poisson pattern.
The model uses each team's expected goals (xG) to build a Poisson probability table. It sums the probabilities of all scorelines where total goals exceed (Over) or stay below (Under) the specified line.