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Postseason Advantages Quantified for NCAA Division I
There are two provable advantages in the NCAA postseason that are independent of the quality of the teams involved: home-field advantage and postseason experience. These are not independent variables, since the same teams tend to both host and have more postseason experience, so it's necessary to control the experiment to separate the two. As it turns out, the best fit to the data is found using an advantage of 5% for each of those factors, so those numbers will be incorporated into the published ISR-based probability factors beginning with the 2009 tournament.
For the purposes of this definition, I'm using the number of postseason games played by the team in the previous five years as the measure and defining an advantage as having played more games than an opponent. Obviously, there are more specific measures that could be used.
In order to find the magnitude of the advantage from postseason experience, I selected the pool of postseason games from 1999-2008 that were played between teams with varying levels of postseason experience on neutral-site field; either in a regional at a third school or in Omaha. There were 580 such games. Using the ISR-based probability formula, the expected wins total for the team with more experience is 334; the actual number of wins is 364. This corresponds, with some rounding, to a 5% per game advantage [(364 - 334) / 580 = .052]. Notice that using the ISR-based probability formula renders the exercise quality-neutral; we're not looking at whether the better team wins, we're looking at whether the better team wins as often as expected.
There's not a corresponding experiment that can be done for home field advantage, since there have only been 15 games played where the home and visiting team had the same amount of experience. However, if you add the experience advantage above into the probability formula, you find that the home field advantage similarly adds a 5% advantage per game. Since this corresponds to the HFA for regular season games over time, this looks quite reasonable.
Boyd's World-> Filing Cabinet-> Postseason Advantages Quantified for NCAA Division I | About the author, Boyd Nation |