A price is a probability with a margin on top, corrected all week by the people betting into it.
A bookmaker starts where we start, with a model, and a trader adjusts before anything is published. Convert each published price to a percentage and the results for a match sum to more than 100%; the excess is the margin, built into the price rather than charged as a fee. On a heavily traded league it might be two or three points, on an obscure division eight or more — which is why a price can never be read as a probability directly.
Once a price is live it stops being the bookmaker's opinion and starts being everyone's. Money shortens the side taking it, and news moves it too: a team sheet an hour before kick-off can shift a match result price several points. A price is a running correction, not a fixed view.
By kick-off, everything public about the match is in the price. The closing line with the margin removed is the best published estimate anyone has, which makes it the hardest honest test. Every night each of our numbers is set beside it for the same match and market, and where the close beats us it shows up on the record page in the same table as everything else. A probability is not a tip. 18+, and please gamble responsibly.