# The Basics Of College Basketball RPI

Posted By on Mar 9, 2012 | 2 comments

The Basics Of The Ratings Percentage Index AKA College Basketball RPI

The Rating Percentage Index or college basketball rpi is a quantity commonly used to determine college basketball rankings, although it is also used to determine rankings of baseball teams as well. The system takes into consideration the wins and losses of a particular team as well as its schedule strength. At present, the NCAA is one of the main athletic organizations that commonly use baseball and basketball RPI. In fact, college basketball rpi has been used to determine college basketball rankings since 1981, and is the primary system used to determine the eligibility and ranking of teams for the men’s basketball playoffs and women’s basketball tournaments.

The currently used formula for determining college basketball rpi at the collegiate level is:

RPI = (WP * 0.25) + (OWP * 0.50) + (OOWP * 0.25)

In this formula, WP stands for Winning Percentage, while OWP and OOWP stands for Opponents’ Winning Percentage and Opponents’ Opponents’ Winning Percentage respectively. In order to determine the WP, a particular team’s total number of wins is divided by the number of games that the team has played.

Based on the above formula, a team’s college basketball rpi represents its winning percentage, which counts for 25%, the opponents’ winning percentage, which counts for 50%, and the winning percentage of the opponents’ opponents, which counts for 25%. In this case, the winning percentage of the opponent and the winning percentage of the opponents’ opponents represent the strength of schedule or SOS. SOS therefore represents 75% of the team’s basketball RPI and is 2/3 of the winning percentage of the opponents. Going by this formula, the SOS is also 1/3 the winning percentage of the opponents’ opponents.

From a statistical angle, the basketball rpi actually has little theoretical basis. More accurate ranking systems also take into consideration the margin of victory of the games that a particular team has played, and even statistics other than win to loss ratios. This means that the rpi college basketball isn’t necessarily the best or most accurate way to predict the results of basketball games. There have also been numerous instances wherein the margin of victory has been manipulated for the purpose of affecting gambling outcomes.

The college basketball rpi system has also received criticism for emphasizing the SOS or strength of schedule, which many feel gives major conference teams an unfair advantage over other teams. In many instances, teams from the major leagues are often allowed to choose from non-conference opponents, many of which are considerably weaker performers.