I'm sure somebody has made this calculation before, but I couldn't find it on the web, so here is my version of calculating the predicted win percentage of a football game, based on the spread and over/under. You get the spread and over/under from donbest.com or most gambling sites and sports sites.
The idea of Pythagorean win percentage is that if you know how many points a team gives up and how many they score, you can estimate the win percentage. as follows:
Win pct = (points scored)^2/ [(points scored)^2 + (points allowed)^2]
OK, so the football betting line gives you the Las Vegas estimate (about the best in the world) of point differential = points scored-points allowed.
And the overunder is the best estimate of
total points = points scored plus points allowed.
So, you can calculate an estimate for points scored = 1/2 * (overunder plus spread) .
An estimate for points allowed is 1/2 (overunder - spread).
As an example, on Sunday Sept 25, the Miami Dolphins are favered by 7.5 points, with the overunder at 42.5
Predicted Miami points = 0.5* (42.5 + 7.5) = 25
Predicted Cleveland points =0.5 * (42.5- 7.5) = 17.5
Miami estimated win probability = (25^2)/(25^2 + 17.5^2) = .671
If you could play like thatl all season, that's pretty good. For example an 11-5 team is .688, 10-6 is .625.
By the way, I calculated this just for fun. It's not intended to be a betting tool. I'm not a bettor, because I believe that 10% fee takes pretty good care of the bookies, and they are better than us.
The idea of Pythagorean win percentage is that if you know how many points a team gives up and how many they score, you can estimate the win percentage. as follows:
Win pct = (points scored)^2/ [(points scored)^2 + (points allowed)^2]
OK, so the football betting line gives you the Las Vegas estimate (about the best in the world) of point differential = points scored-points allowed.
And the overunder is the best estimate of
total points = points scored plus points allowed.
So, you can calculate an estimate for points scored = 1/2 * (overunder plus spread) .
An estimate for points allowed is 1/2 (overunder - spread).
As an example, on Sunday Sept 25, the Miami Dolphins are favered by 7.5 points, with the overunder at 42.5
Predicted Miami points = 0.5* (42.5 + 7.5) = 25
Predicted Cleveland points =0.5 * (42.5- 7.5) = 17.5
Miami estimated win probability = (25^2)/(25^2 + 17.5^2) = .671
If you could play like thatl all season, that's pretty good. For example an 11-5 team is .688, 10-6 is .625.
By the way, I calculated this just for fun. It's not intended to be a betting tool. I'm not a bettor, because I believe that 10% fee takes pretty good care of the bookies, and they are better than us.
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