Monday, March 14, 2011

Probabilities/Odds For NCAA Tournament Advancement

We've added a page that lists the probabilities for reaching each of the rounds of the tournament - along with winning it all - for all 68 teams.

The page is here: http://www.rpiforecast.com/tourneyprobabilites.html

There are two types of probabilites listed: UNCONDITIONAL and CONDITIONAL

You are probably most familiar with UNCONDITIONAL. That tells you the overall probability of a team reaching each of the rounds. The CONDITIONAL probabilities, however, tell you the probability that a team reaches a round given that it has already reached the previous round. For example, a team like UT-San Antonio may have a very low unconditional probability of reaching the Final 4, however, conditional on it having already reached the Elite 8, it will have a much higher probability. We'll update the webpage as we reach each new round with new probabilities. These will change as teams (and potential future matchups) are eliminated.

How'd we do?

The main goals (and the main strengths) of this site are (1) to provide accurate predictions of end-of-season RPI, and (2) to provide up to the minute current RPI. A secondary goal is to provide predictions of at-large bids and seeds. Up until this season, we were not predicting seeds, just bids. This season, we decided to use the "Dance Card" formulas for seeds in addition to the at-large formulas. In terms of at-large bids, we did a bit worse than seasons past - missing 3 (VCU, USC, and Florida State). However, only one major bracketologist got even 67 out of 68 (Fox Sports). As far as I have seen, nobody got 68. Based on the Bracket Project website, only a handful got 66 or better. Most were 65 or less, so 3 is nothing to be ashamed of - especially considering the fact that this is all done using a simple formula. Typically the Dance Card formula misses no less than 1 or 2, so this season was unusual.

As for seeds, there IS something to be ashamed of. Quite simply, the seed predictions stunk! In the name of objectivity, we wanted to avoid tweaking the seeds and let the formulas do all the work. However, something obviously needs to be done. The plan for next season is probably to abandon the formulas for seeding - or at least to modify them to allow for some "human analysis". We'll stick with the at-large formulas and figure out a better way to seed the teams. At this point, the seeding decisions seem to be more complicated than can be explained by a simple formula.

The big benefit from projecting bids/seeds relative to other bracketologists ought to come EARLIER in the season, rather than LATER. In fact, RPIFORECAST is one of the best at predicting seeds in December/January and February. We have archived all of the major bracketologists' predictions this season and will be determining who were the best and worst EARLY in the season.

Anyway, thanks for visiting, enjoy the tournament, and look for some more exciting things next season!

Monday, February 21, 2011

Bracket Predictions

I've decided to switch up the at-large and seeding formulas a bit. I had been using an equation that includes conference affiliation and representation on the selection committee. However, just today, I switched to one of the models which does not take these into account. This was mainly because of the problem with the MWC teams seeds (BYU, SDSU, etc). Because the MWC has never been this good, it may not make sense to assume that the same "bias" would exist against them this season. Anyway, BYU immediately jumped to a 2 seed and SDSU to a 5 seed (the highest 5 seed).

http://www.rpiforecast.com/bracket.html