Reading it
The single most important rule in the model, and the reason it can disagree with the market. Bookmakers over-weight recent form; five matches of a counting stat is mostly noise. A player with twelve appearances is described more by his position group than by himself, and the projection says so through the sample-size column.
Definitions describe what Per90’s licensed data feed records, which is not always what a given bookmaker settles on. When the two differ, the bookmaker’s rules decide a bet.
Where it appears on Per90
- Player props research guide — the method this term belongs to, start to finish.
- Methodology — how the model is built and how well each market is priced.