How to Use a Poisson Model for Football

The model

Poisson estimates the chance of a team scoring zero, one, two or more goals from an expected scoring rate.

Expected-goal inputs should reflect attack, defence, venue, line-ups and competition strength.

Score probabilities can be summed into home, draw, away, over/under and BTTS markets.

A basic model misses correlation, red cards, game state and tactical changes.

Can average goals replace xG? — Yes, but they may be noisier.

Are exact scores reliable? — They are estimates with high variance.