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Here We Go: The Overvaluation of RPI in College Basketball

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Imagine if you were forced to rank every single team in college hoops based on a formula of your choosing. Unfortunately for you, those handy top 25 polls don't exist yet, and the sport has hand-picked you, and only you, to create an unbiased ranking system. Might want to put on some pants for this one, champ. But here's the kicker: Now imagine if two of the most widely used metrics, Rating Percentage Index (RPI) and Strength of Schedule (SOS), have not even been created yet. So how on Earth are you going to do this?

The above scenario is especially intriguing to me because without a tool like RPI as a crutch, most people would be at a loss to come up with a legitimate way of going about this task. Do you focus on things like on-court performance, or are wins and losses the single greatest measuring stick? And what about conference strength, quality wins, home vs. away splits, or god forbid, defensive and offensive efficiency rankings?

This is the time of year where media outlets love to post the resumes of comparable teams and debate endlessly about which one deserves an NCAA bid over the other. And, like clockwork, the minions resort to a grand total of two metrics, RPI and SOS rankings, to back up their claims. One media member, who I won't name, even went as far as to laud a certain school as an NCAA Tournament lock simply because they owned a top ranked SOS. Not overly terrible, sure, but I'd like to remind you this particular comment came way back in January.

Having a great SOS doesn't tell us anything. Playing a bunch of good teams doesn't amount to squat if you aren't winning those games. There's simply no further elaboration there, no remaining analysis that can be done. It's just a number that tells us about 0.01% of the picture, and thankfully, most sane people in this country have come to this conclusion.

But then we arrive at RPI, a mystical concoction of ingredients that 99.9% of fans have no idea how to calculate. They see the final rankings, point to them religiously, and rarely lift a finger to actually learn about about what goes into the formula and what doesn't. Here's what you need to know (via

What is the formula?

The basic formula is 25% team winning percentage (WP), 50% opponents' average winning percentage (OWP), and 25% opponents' opponents' average winning percentage (OOWP).

For the 2004-05 season, the formula was changed to give more weight to road wins vs home wins. A team's win total for RPI purposes is 1.4 * road wins + neutral site wins + 0.6 * home wins. A team's losses is calculated as 0.6 * road losses + neutral site losses + 1.4 * home losses.

For example, a team that is 4-0 at home and 2-7 on the road has a RPI record of 5.2 wins (1.4 * 2 + 0.6 * 4) and 4.2 losses (0.6 * 7). That means that even though it is 6-7, for RPI purposes, it is above .500 (5.2-4.2).

This "weighted" record is only used for the 25% of the formula that is each team's winning percentage. The regular team records are used to calculate OWP and OOWP.

As always, only games against Division I opponents count in the RPI.

Are you utterly blown away by the intricate details of this miraculous system? Or has the veil of secrecy been lifted, only to find the equivalent of a polished turd sitting in the corner? The single greatest way to evaluate a team is by their play on the court, and based on the formula above, that factor is nowhere to be seen. Absurd.

That's not to say RPI isn't a useful resource. It most certainly can be when coupled with a handful of other equal, if not more important measures of analysis. Regardless of that fact, RPI still remains the gold standard for evaluating college basketball teams. We know this because of those fine folks over at the NCAA selection committee, who have proven time and again that they value RPI much, much higher than any other statistical measure. In a way, this is an indictment on how simple-minded our entire culture has become. We see something that appears to work, and we hold onto it like it's the greatest thing in the world, ignoring better, more efficient measures that might come along simply because we fear change.

Considering the depth of its use, RPI is an absolute joke and needs to be taken out behind the woodshed. Some of the most knowledgeable, albeit muffled, minds in the sport already know this better than anyone, but the NCAA selection committee isn't one to endorse outside-the-box thinking. The great Jay Bilas essentially said this same thing on Twitter yesterday, prompting a growing audience of bloggers and keen media members simultaneously pumped their fists.

There are much better things out there than RPI (here and here, for starters). Hopefully one day the people who make the most important decisions in the sport will take notice.



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