An Elo-style rating (after Arpad Elo's chess system, via Drapkin and Forsyth's 'The Punter's Revenge'). Every team carries a points score; each match both sides pay into a kitty and the winner takes it, so the number tracks current form with a memory.
How it works
Every team starts the season on 1000 points.
Before a game the home side pays 7% of its points into the kitty and the away side 5% - the bigger home stake reflects home advantage.
Home win: the home team takes the whole kitty. Away win: the away team takes it. Draw: split evenly, which means the away side gains a little and the home side loses a little.
Ratings are recomputed game by game through the season, so the value used for a fixture is each side's rating before that game.
The column shows Rate = home rating − away rating.
home rating minus away rating, e.g. 1147.5 − 980 = +167
How BetChair calls it
Above +150 = home win, below −250 = away win, in between = draw. The asymmetry is deliberate: an away side needs a clearly bigger edge to be favoured. Everyone starts level, so early-season Rate is near 0 and reads as a draw.
Where it shines
Has a memory: it does not forget a run of results the moment a sixth game is played.
Rewards beating good teams more than beating bad ones, because good teams stake more.
Where it falls down
Everyone starts on 1000 - promoted and relegated sides are treated as average until results say otherwise.
The 7%/5% stakes and the thresholds are fixed by hand, not fitted.