24 March 2013

Rating Systems Challenge: Shocking Upset Busts Brackets

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.

Another exciting night of college basketball has shaken up the race for top dog in the 2013 Rational Pastime Rating Systems Challenge.

After the third full day of the NCAA Tournament we see the Sports Reference efficiency system take the lead, edging out Chalk and other brackets by the smallest of margins. Five other systems are tied with Chalk in total points but have more possible points remaining.

Interestingly, sitting in second place behind one of the more advanced rating systems is one of the least sophisticated entrants: the ESPN Preseason Poll. Both the Sports Reference and ESPN Preseason systems benefited from correctly picking 6 Arizona to reach the Sweet Sixteen. Bringing up the rear yet again is our perennial laggard: the Nolan Power Index. NPI unfortunately projected 5 Virginia Commonwealth and 6 Memphis to advance; Big Ten powerhouses from the Wolverine State easily felled them both.

Of course, the stories of the day were the two big upsets: 12 Oregon's tidy win over 4 Saint Louis and 9 Wichita State's "shocking" (sorry) victory over the postseason poll favorite, top-seeded Gonzaga. Keep reading after the jump to discover what effect this will have on the various systems' performance in the remainder of the NCAA Tournament.

As you can see on the leaderboard above, the postseason polls and the Nolan Power Index lost their NCAA Champion pick when the Wichita State Shockers upended Gonzaga. All three find themsevles at a significant disadvantage for the rest of the tournament. Gonzaga's fall hobbled NPI especially, which already lags 92% of brackets submitted at ESPN.com and has correctly picked only 55% of match-ups so far.

The damage is not confined to NPI and the postseason polls; a full fourteen rating systems placed Gonzaga in the Final Four. The LRMC Bayesian system expected Gonzaga to reach the finals (losing to 3 Florida). With the Bulldogs' departure, there are only four systems with an intact Final Four: the ESPN National Bracket, the two preseason polls, and the Sonny Moore bracket.

Today's games yield more bracket busting potential. A full forty-one Final Four picks are on the line tomorrow in the form of one-seeds Kansas and Indiana, two-seeds Duke, Miami and Ohio State, and three-seed Florida. The only systems that can directly benefit from any of these upsets, however, are the preseason polls who ranked 7 San Diego State high enough to send them to the Sweet Sixteen.

Ten teams who were not their Super Region's top seed will vie to advance. With Kansas State and Georgetown out of the way, two are guaranteed to be underdogs: SDSU and 12 Ole Miss are the highest remaining seeds in their respective Super Regions.

Best of all, tomorrow we get to see if the clock strikes midnight for our two Cinderellas: 13 LaSalle and 15 Florida Gulf Coast. Stay tuned to see how the various rating systems handle these and other developments as March Madness continues.


Matt Mitchell said...

I know it might be late, but I saw this at the Wages of Wins blog: http://wagesofwins.com/2013/03/20/ncaa-picks-part-the-final-we-threw-in-the-kitchen-sink/
I'd be interested to see how it stacked up against these other systems.

JD Mathewson said...

Thanks, Matt, I'll take a look at it.