Saturday, March 20, 2010

Prediction System Bracket Challenge: Rd 1 Update

As mentioned previously, I set up a group on ESPN’s Tournament Challenge to track how the bracket predictions from about a dozen different ratings/prediction system are doing.  Here’s a quick review of where everything stands after Friday.


As you can see, everybody picked Kansas except for Yet Another Basketball Blog’s cupcakes-removed efficiency ratings.  Some of you might be saying “Wait!  I thought Duke was #1 in Pomeroy!”  Well, you’re right.  But they weren’t on Wednesday evening, when I filled out the brackets - Kansas was in front by about 0.001.  I’m pretty sure that’s the only day in the last month where that was true, but this is a good example of the fact that rankings and ratings are considerably different.  Pomeroy’s ratings say that Kansas and Duke are essentially equal, and both are considerably ahead of the pack.  If you only look at the rankings, all you see (today) is that the top three are Duke, Kansas, and Wisconsin.  Quite a difference.

At any rate, the biggest surprises in the above table have to be that the RPI is tied for first, while the bracket based on Vegas Watch’s attempt to mimic the sportsbook markets is tied for last.  However, look at the PPR (Possible Points Remaining) – Vegas Watch is actually tied for first.  That’s kind of the whole point of his approach – a lot of these first round games are tossups, and it’s just luck whether you pick them right, which is why you need to keep in mind the overall odds of a team advancing to a certain round, instead of merely looking at their most likely matchup at that point.

The fact that Team and two of Sagarin’s ratings (and specifically NOT the Elo rating) are tied at the top, is definitely not a surprise, as these guys plus Pomeroy are what I’d consider the Big Three of college basketball ratings.

I’m happy to report that my Similarity Scores system is tied with Pomeroy (which is the foundation for the similarity analysis) - though we’ve gotten there via differing picks, and Pomeroy has one more Sweet 16 team alive.

My comrade over at UFR isn’t going to be quite as pleased, as the Martin Manley rankings are only 1 game from last, and have the fewest potential future points.

In the grand scheme of things, the first round isn’t too important, so I’ll be more curious to see how things stand after the whole weekend is over.  I anticipate a comeback by Vegas Watch – and of course I’m rooting for my Similarity Scores to pass Pomeroy.

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