This is my submission to the kaggle march mania competition. It was made with the encouragement of the Columbia Data Science Society.
The final model I ended up using was gbm. It aggregates a bunch of information, much of which ended up being pretty irrelevant. In particular I create some aggregate statistics about each team over the regular season, like win percent, and margins for winning/losing (surprisingly winning margin is super predcitive).
I use the PlayerRatings library to calculate a glicko rating for each team, and then calculate a prediction from that (along with raw difference in rating).
I merge in some tournament information, including seed number (obviously very predictive). Finally I added some of the ranking systems that Nate Silver identifies as important, Pomeroy, Moore, and LRMC. I couldn't get easy access to Sagarin's predictor ratings, so I used Sagarin's regular ratings.
The gbm's relative influence information is:
var rel.inf
seedn.diff 45.272478
glickopred 14.791104
winpct.diff 6.241056
wmargin_avg.diff 5.389482
glicko.diff 5.316646
POM.diff 4.761056
SAG.diff 4.173324
wmargin_avg.1 4.018286
MOR.diff 3.604845
LMC.diff 2.514890
margin_avg.diff 2.133449
wmargin_avg.2 1.783383
seedpred 0.000000