30 March 2013

Rating Systems Challenge: Preseason Polls Dominating? Don't Be So A-maized.

This post is one in a series investigating how the various college basketball rating systems predict the men's NCAA Tournament. Click here to read the rest.

Was that awful pun really necessary? Yes, yes it was.

Okay, no it wasn't, but I hope it drew your attention to something that seems amazing but is actually rather common. The preseason polls from AP and ESPN tend to do rather well in forecasting NCAA Tournament results. Last year, the AP Preseason Poll finished fourth overall in the Rating Systems challenge, six spots ahead of the AP Postseason Poll.

On average, the preseason polls are actually slightly more accurate than postseason polls at predicting postseason success. Perhaps the preseason polls are better at measuring the baseline talent level. Perhaps the postseason polls are poisoned by recency bias. Either way, this is the pattern, and it's a pattern that is playing out again this season. Largely thanks to 4 Michigan's (get it? maize?) upset of 1 Kansas, the ESPN and AP Preseason Polls rank #1 and #3, respectively.

Will their lead hold up? Maybe, but most likely not. Read why after the jump.

Like I said, the preseason polls are performing well so far—the ESPN Preseason Poll is doing so well that it's beating 99.6% of all brackets in the ESPN Tournament Challenge. However, since they both picked Indiana to win it all, their opportunities to earn more points are limited. For these systems to have a shot at winning the 2013 Rating Systems Challenge, 3 Florida will have to miss the Final Four. Otherwise, Sports Reference, Survival and Pomeroy will take the lead. Even if Florida loses, a 1 Louisville title means that the preseason polls will probably lose to the FiveThirtyEight.

You may notice that, for the first time in this tournament, a significant number of the systems have outperformed the Chalk bracket. With three top seeds eliminated, expect this trend to continue through the NCAA Championship.

With three 1-seeds eliminated, there's a lot of room for lower seeds to advance to the Final Four. Four systems picked 4 Ohio State to advance out of the West—the only lower seed that any of the systems expect to advance tomorrow. 9 Wichita State's Cinderella run makes this even more likely.

In terms of Sunday's games, there is at least one system that picked a lower seed to advance in both contests. Two systems pick 2 Duke to overcome top-seeded Louisville. Two systems (not the same ones) put Michigan in the Final Four, and fully nine systems expect the Gators to reach Atlanta.

With five projected Final Four picks still alive, each and every one of these games has major Rating Systems Challenge implications.* Also, I suppose they impact the Tournament in some way. Follow us on Twitter @RationalPastime or tune in tomorrow to see how well each system performed in the Regional Finals.

*Okay, not so much Syracuse-Marquette

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