## Using Graph Theory To Predict NCAA Tournament Outcomes 91

New submitter SocratesJedi writes

*"Like many technically-minded people, I don't have a lot of time to keep up with sports. Nevertheless, trying to predict the outcome of the NCAA men's basketball tournament is a fun activity to share with friends, family and colleagues. This year, I abandoned my usual strategy of quasi-randomly choosing teams and instead modeled the win-loss history of all Division I teams as a weighted network. The network included information from 5242 games played during the 2011-2012 season. From this, teams came be ranked using tools from graph theory and those rankings can be used to predict tournament outcomes. Without any**a priori*information, this method accurately identified all the #1 seeds in the top 5 best teams. It also predicts that at least one underdog, Belmont (#14 seed), will reach the Elite Eight. Although the ultimate test will be how well it predicts tournament outcomes, initial benchmarks suggest 70-80% accuracy would not be unreasonable."
## As a sports fan (Score:4, Interesting)

Some problems I see. Disclaimer: I know there's a margin of error here as the author said, and I know my observations will be based largely on anecdotal evidence, making it inferior. But if sports were so easy to predict there would be no sports gambling.

- That's probably too far for Belmont; a #14 has only ever gotten as far as the Sweet 16, twice (Cleveland State '86, Chattanooga '97). Lowest seed to make an Elite 8 is Missouri in 2002 as a #12 . Belmont is actually going to be one of the more popular upset picks, but they would have to upset two far superior teams twice in 3 days.

- It's a bit too "chalk". #1 seeds generally survive the first two games (undefeated against #16's, 55-14 v. #8's, 59-6 v. #9's), but the #2's have it worse (only four losses v. #15's, but 58-21 v. #7's and 29-21 v. #10's). I know two #12's, a #13 and a #14 doesn't seem like "chalk" but historically it's much more likely that we'll see more #5-7 or #10-11's. To have only one #2 not make the Elite 8 and all the #1's would be almost unheard of.

- A #12 always beats a #5, but three of them doing so in one year would seem unlikely, as they're only 39-89 overall.

- Some of the other first round matchups seem a bit improbably. It has every #6 and every #7 winning, for example.