Now that I am comparing my simulation results to the Las Vegas-Hilton oddsmakers. I need to post the conversion algorithm to go from Vegas odds to an expected win percentage. You will often see a Vegas baseball favorite listed as -155. Well does that mean they are saying the team has a 55%, 60%, 65% etc..., chance of winning? The conversion formula is:
WinExp% = [ABS(Favorite + 5) / 100] / ([ABS(Favorite + 5) / 100] + 1)
The -155 we looked at in the example becomes...
WinExp% = [ABS(-155 + 5) / 100] / ([ABS(-155 + 5) / 100] + 1)
WinExp% = 1.5 / (1.5 + 1)
Which gives us... 1.5 / 2.5 = 0.6 or a 60% chance of winning.
This algorithm had to strip out the house edge that Vegas add to each line.
Feel free to use my handy Money Line to Win Percentage Calculator
, via Google docs.