Originally Posted by
wantitall4moi
As with everything else math related here people need a dictionary or at least get the semantics correct.
There is no set PROBABILITY based on a line. The example given was -230/210 and 'probabilities' of 32% and 69%. All the overage does if give the books theoretical hold based on balanced action at those splits. It surely doesnt mean that Miami has a 'no vig' probability of 69.7% to win the game. What happens if the line moves to -280/265 does Miamis probability magically go to 73.7%? Not hardly, their PROBABILITY to win the game doesnt move one bit, the ODDS did based on people betting the game.
Now if one had a perfectly calibrated machine that was able to actually determine the true PROBABILITY of one team winning and then compared it to the odds then you could find 'value'. But that isnt going to happen. A lot of guys have models but not many are good enough to even start figuring how valid they are let alone using them to determine a fair probability.
This is the same math mumbo jumbo guys have been spouting forever. This is actually pretty generic stuff and the simplest way books use to calculate lines they throw out, at least books that are out right clones of other books. All it is really good for is checking to see how much hold a book is taking out of you when you see a set of lines. A more contemporary example would be today in baseball, as of right now in the Dodgers/cubs game. 5 dimes is -102/108, Pinnacle is +102/108, bookmaker is -117/-103, betonline is -105/-105, and Legends is -110/-110,. So according to this post the odds of Dodgers winning (no vig) range from 48.1% to 53.9%? Same exact match up but one books gives them less than a 50% chance (actually a few of them) while another gives them nearly 54% chance? No it just means one book is taking a 1.41 or so hold on the game, while the other (the one dealing a 20 cent line) is taking 4.45% hold, more than 3 times as much.
The sooner people realize betting odds have ABSOLUTELY NOTHING to do with actual win chance/probability the better off they will be. This post is a good example of showing how books make their money on the odds they offer, it surely doesnt give the actual win probability of one side versus the other. At best it shows what percentage a bettor has to win at the odds they are checking to break even.
EDIT: actually one small correction, the odds for that dodgers cubs game were for the closing lines of the game not current odds for the game.