Wednesday, March 16, 2011

What's the Point: RPI

For a while now, RPI has been arguably the most important stat for a team qualifying for the NCAA tournament. Even over wins and losses, RPI rules on selection Sunday, as the casual observer can literally pick the at large bids to the tournament in order of RPI. Although important, RPI does not come close to telling the whole story of a team's worthiness to dance. Instead of fairly judging the standing of a team, this arcane ranking system skews the rankings to protect the blue-blood programs of college basketball.

The RPI is composed of three parts. 25% of the number depends on a team's winning percentage, 50% depends on opponents' winning percentage, and 25% depends on opponents' opponents' winning percentage. This boils down to 25% of the ranking based on winning, and 75% due to strength of schedule. It is true that strength of schedule is very important when evaluating a team. But, should it be the crucial, deciding factor in judging whether a team is tournament worthy?

RPI does not take into account margin of victory, so a blowout of a powerhouse means the same as a squeaker over a weak mid-major. It also does not account for games against non-division- one schools. This means that a loss to a division II school does not affect your RPI. How can an observer get a full picture of a team's success through this stat? There is simply no way to do it.

A better ranking system would be one that puts more emphasis on wins, rather than only getting 25% credit for one. If a team loaded up its schedule with quality opponents, they would hardly have to break 500 to get into the tournament under RPI influence. The perfect case is Michigan State, who despite having only 4 more wins than losses, made the tournament as a ten seed!

The RPI system can give rise to a vicious cycle. Since it is 75% based on strength of schedule, a team will only try to schedule opponents who are not only good but who also have strong schedules, since 25% of a team's ranking is based on opponents' opponents' winning percentage. So, with a few exceptions, the teams with strong schedules all play each other and do not have to sweat on selection Sunday, while many teams are left out in the cold.

This year, 5 teams with 14 losses are in the tournament. 5! This just shows how actually winning games has fallen so far down the priority list. RPI is a misleading statistic that surely helped many of these teams into the tournament. The tournament is supposed to be about winning games, not about how tough your schedule was.

What's the Point is a weekly column written by David Straple. Feel free to comment.

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