William Hill's Latest title odds. 6-5 Manchester City 7-2 Arsenal 7-2 Chelsea 8-1 Liverpool 25-1 Manchester United 28-1 Everton 50-1 Tottenham
I don't know the science but I know they calculate where who people are putting money on (united probably had quite a few bets on them at the start of the season which would have had an impact) and i'd imagine the rest is calculated on form and how well a team did on a demo season of Football Manager
6-5 Manchester City 7-2 Chelsea 4-1 Arsenal 6-1 Liverpool 20-1 Manchester United 33-1 Everton 100-1 Tottenham #from 50-1 after yesterday's game.
There isn't a simple answer to that because bookies have several ways of setting the odds. They work on probability but as it's impossible to work out the actual true probability of a team winning, most go with what the betting public perceive the true probability to be. The odds quoted in the OP will change, obviously. What's interesting to me from those listed above is the big gap between us and utd.