The prediction column represents the win probability band my system gives to the team I expect to win. Meaning my system gives a percent confidence in each prediction, and the column represents the confidence range a game fell into. The W-L column represents my record in predicting the games in that probability band.
Overall my algorithm has predicted the winner in about 81% of games, but as Ken Pomeroy pointed out in his latest blog post, that is a meaningless statistic since so many of these games represent lopsided competitions. A better auditing statistic is how often a system is able to predict a winner in a certain probability band. For instance, my system should predict the correct winner somewhere between 50-55.9% for games that fall into that probability band. If my system is correctly predicting 65% of those games (or 35%), the system would need tweaking. So far the system has held up pretty well using this type of tracking.
There is also a matter of how well a system predicts the margin and total. Since I do not systematically track my predictions versus the spread, I cannot say how well it is doing there. What I can say though is the average difference between my predicted margin and the actual margin is about 8 points per game, which on the surface does not seem very good. My predicted total is off about 16 points on average from the actual total, with a current slight bias towards under-projecting the total. I am not yet sure whether this is due to a low sample.
Posted on 12/5 11:18 AM | IP: Logged
Just passing through, but that's a damn fine correlation, especially down at the lower confidence intervals.
It would be interesting to plot the sample size of each confidence interval over time (as a %age of the total sample size) - if your tweaked algorithm is improving the prediction capability the distribution would shift towards the higher CIs as time progresses. Of course, since you've obviously spent a lot of time on this you probably have an even better way of monitoring improvement :)
Posted on 12/5 11:59 PM | IP: Logged
I believe you really like math.
Posted on 12/12 11:08 PM | IP: Logged
Originally posted by VolunteerusMaximus: I believe you really like math.
Posted on 12/16 11:23 PM | IP: Logged
Posted on 12/16 11:24 PM | IP: Logged
Posted on 12/16 11:42 PM | IP: Logged
The tracking table has been updated through games of December 31st, 2010.