The ratings have been updated to include the Kentucky round robin. The "change" column reflects the change from the data set that did not include the RR to the data set that does (in other words, the change from post-Wake results without the RR to post-Wake results with). As a result, relatively few teams show much of any change. I might only leave this up for a short time, then post the data that shows the change as if the RR had been included all along. A few things to note: 1. The only team that was substantially affected was Kansas CK, who had an exceptionally poor Run for the Roses. I can only hope that they don't still play "You Can't Always Get What You Want" after each round is announced. Below you can see the difference between the two ratings, the blue line representing the ratings that didn't include the round robin and the red line representing those that did. Time periods represent blocks of tournaments (1 = season openers, 2 = Kentucky & Weber, 3 = UNLV & Harvard, 4 = Wake). Some thoughts about what's going on here. I think it's obviously fair to say that going 0-8 at the Kentucky RR is not the equivalent of going 0-8 at any other tournament. To some degree, the ratings already account for this because KU still left the Kentucky weekend with just under a 1600 rating, which is an above average rating. Nevertheless, it's also true that KU's rating at that point almost certainly underrated them. This is a big reason why one of the strengths of the ratings is that they explicitly incorporate a "deviance" element. KU's deviance at that point was still around 100, which means that the system believed that their "true" rating could possibly be as high as 1800. Another mechanism that the ratings use to account for substantial under (or over) rating can be seen pretty easily in the way KU's ratings reacted after the RR. When rated lower, their rating grew much faster after Wake and Harvard in response to their stronger results. In the end, the difference between the two data set produces a difference of about 70 points with a deviance just over 60 points. Over the course of the season, the two ratings will grow closer and closer together.
2. Harvard BS dropped from 2nd to 4th with the inclusion of the RR, falling behind Harvard DH and Michigan AP, although they're all quite close. Harvard DH and Michigan both had quite strong round robins (1st and 2nd respectively). Still, some might question whether they should jump ahead of BS, who has had an exceptional season so far (32-3 record at included tournaments). This is certainly debatable. However, it should be noted that BS's unadjusted rating is still the best of the three. It's just that they have fewer debates and so their deviance is currently higher, which drops their adjusted rating (for more on why the rankings are based on the adjusted ratings, check the FAQ. Over time this discrepancy should even out. By the end of the season, most active teams end up with deviances fairly close to one another.
2 Comments
Keegan
11/24/2014 12:04:42 pm
Number of rounds shouldn't count as high as it currently does I think. It should matter only in so far as it helps to establish accurate rating but not so high as to result in a drop. IT seems it might be useful to cause a bigger gap to be produced between the teams to off set this effect, but not really sure how to make this happen.
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jregnier
11/24/2014 01:10:29 pm
The reason that number of rounds is really important is for statistical confidence. However, it won't be very long until the effect of number of rounds is virtually eliminated for the majority of teams. If a team's deviance goes below 50, it is automatically reset at a minimum of 50 at the beginning of the next time period. That means that most active teams will be on relatively equal footing. As I look at last year's pre-bid results, the vast majority of teams in the top 100 had deviances in the 60-80 range, with almost everybody in the top 50 somewhere between 60 & 70.
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