Monday, March 14, 2016

Thoughts on the bracket selection, part 1

I followed the "bracketology" debate more closely than usual this year, for two reasons: (1) until recently, the Badgers were a bubble team (at best), and (2) I used the power of T-Rank to produce an objective bracket prediction (T-Ranketology).

I was satisfied with T-Ranketology's results. It missed three at-larges: Syracuse, Vanderbilt, and Tulsa (instead of Saint Mary's, St. Bonventure, and South Carolina). This was about average for the brackets over at, and if you look at the final "consensus" bracket, T-Ranketology would have had 67 of 68 (with only South Carolina not being a consensus tourney team). Seeding predictions were pretty good, too. All in all, not bad for an algorithm.

There's a lot of hootin' and hollerin' about the committee's selections, and I agree with much of it. But I wanted to take a look at the six teams T-Ranketology was wrong on, plus one other, to see maybe what the committee was thinking and if the algorithm could be improved to reflect that thinking or lack thereof.


Syracuse's overall resume was not great, but the one big trump card they had was a road win at Duke, which is worth like a million resume points. Add a couple other decent (early) wins, and they're left ranked No. 32 in T-Ranketology's "resume" ranking, which is an attempt to simulate the committee's fixation with "top 50" wins, etc. They were also 50th in T-Rank's "wins against bubble" rating, so right on the bubble there. But they were very poor in basic RPI, and had tanked coming down the stretch, leading to a bad elo ranking (which usually pretty well approximates current "sentiments" about how good a team is). All in all, this left Syracuse the sixth team out in T-Ranketology.

But I'm not going to worry about fiddling with T-Ranketology to get Syracuse into the field, because they were clearly a special case.
The committee chairman had been saying for weeks that Syracuse was going to get special consideration because Syracuse played like shit when Jim Boeheim was serving his 9-game suspension in the middle of the season. Basketball people can look at that argument and see the absurdity on its face -- Syracuse lost five games without Boeheim, and even if you think he is super-god-coach, they almost certainly lose 4 if not all 5 of those games with him. But the committee is not composed of basketball people, so alas. In any event, the handwriting had been on the wall: barring a monumental collapse (which almost happened) Syracuse was going to be in the tournament. If I had been manually fiddling with the T-Ranketolgy bracket, I'd have put Syracuse in for sure.


Vanderbilt was the eighth team out in the final T-Ranketology, mainly because it was not in the top 50 of any of the four resume-based metrics the algorithm considered. On the other hand, unlike Syracuse, it was not terrible in any of those metrics, finishing top-70 in all of them.

Clearly Vanderbilt got in because of its efficiency rating. Vandy finished the season ranked 27th in the Kenpom ratings, and top-30 teams always get in nowadays. I think this is why they're slotted in the play-in round against another Kenpom darling, Wichita St.: the committee put two good teams with bad resumes into the ring against each other and said, "If you're so good, prove it."

When I first started T-Ranketology it was loosely modeled after the Easy Bubble Solver, which just averages RPI and Kenpom ranking. Of course, I used T-Rank instead of Kenpom rating, but it was pretty much the same idea. Eventually I took out the efficiency rating component because for good or bad I think it just doesn't play a very big role in the selection or even seeding process, at least not systematically. But I think there's good evidence that it comes into play in edge cases, and I think it's pretty clear that's what got Vandy in. I may have to work in some kind of "top 30" efficiency rating bonus to account for this.

(By the way, I think Syracuse was also helped by a decent Kenpom rating, though I don't think it wouldn't have been enough without The Boeheim Excuse.)


Tulsa was the real shocker, what John Gasaway calls the committee's annual "grenade." But it wasn't a huge shocker to T-Ranketology, which had Tulsa just the fifth team out -- ahead of both Syracuse and Vanderbilt! Indeed, before its loss to Memphis in the AAC tourney on Friday, T-Ranketology had Tulsa the last team in the field.

Why? Like Syracuse, Tulsa scored well in the "resume" score that approximates top 50 wins, etc. This is by far the stupidest possible measure you could come up with, but I'm pleased to say that I think I've done a pretty good job of modeling this particular madness. Tulsa's inclusion in the field of 68 shows that I probably need to weigh it even a little more.

But I think there's another lesson for Tulsa's selection. The committee first gets together early in championship week to get ahead start on the process. As a result, by Friday (when Tulsa got stomped by lowly Memphis) the committee has already made some provisional decisions about which teams it thinks are good enough. I'm pretty sure that Tulsa's resume had already been found deserving by Friday. Here's the way the human mind works: once it decides something, that decision sets. It's like a boulder in a divot; you need a big shove to get it moving again. When new information comes in, we don't start at square one and reevaluate the decision with a blank slate. We say: is this new information enough of a big deal to make me go through this whole process of deciding again? Unsurprisingly, the answer is usually no. This fundamental quality of human psychology (call it laziness if you wish) got Tulsa into the tourney.

(This, by the way, is why college-football-playoff-style in-season tourney rankings are a terrible, terrible idea.)

Well, this has gotten tl;dr so I'm going to stop now. I'll try to post later today with my profound insights into the "snubs."

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