Kentucky head basketball coach John Calipari, March 2012
And with John Calipari’s quote, the College Basketball Power Index – college basketball’s newest ranking system – had penetrated the sport’s landscape just six weeks after its debut on ESPN.com.
Alok Pattani, ESPN’s senior analytics specialist and one of creators of the BPI, notes that ESPN wasn’t the first, nor maybe even the 20th, to formulate a ranking system for college basketball’s 351 Division I teams – all which play vastly different schedules. However, due to the setup of the NCAA College Basketball Tournament, the comparing and contrasting of teams is an essential practice each season.
“We had important data about teams that wasn’t being factored into most – sometimes any – of the ratings systems,” says Jeff Bennett, ESPN senior director of Stats and Analytics, who oversaw the creation of BPI. “We created BPI to give fans, our on-air staff, and, hopefully, the NCAA Selection Committee a better tool to evaluate teams.”
What Makes BPI Different
A major differentiator between BPI and RPI (Ratings Percentage Index) – the primary rating system used by the NCAA Tournament Selection Committee – is that BPI factors in elements within the game, not just the final result. The scoring margin with diminishing returns takes into account the margin of win/loss but doesn’t equate a 40 point win as two times more impressive than a 20 point win. Additionally, BPI examines how many possessions a team has to determine the pace of the game. Pace dictates how many scoring opportunities one team had or didn’t have, resulting in a more or less impressive scoring margin. Most uniquely to BPI, not every win versus the same team is assumed as equal. If a losing team is missing an important player (determined by minutes played), a victory over that team does not hold as much weight with BPI, assuming the missing player will return to the team later in the season.
Comparing RPI and BPI criteria:
Predicting NCAA Tournament Success: BPI vs. RPI
“BPI is designed to be more than a team rating system,” Bennett says. “Unlike RPI, it can be utilized as a predictive rating which forecasts if a team will win a given matchup, a string of games, or even a complete tournament.”
In BPI’s two years of existence, the team who ranked No. 1 in BPI on Selection Sunday has gone on to win the National Championship. This bodes well for Arizona, who is a very likely to finish No.1 in BPI this season.
Additionally, all eight teams to make the Final Four in 2012 and 2013 ranked better in BPI than RPI on Selection Sunday:
BPI has proven to be a better tool when filling out a bracket prior to the start of the tournament. Since the 2007 NCAA Basketball Tournament, filling out a bracket and riding the higher rated BPI teams throughout, on average would have yielded a 66% correct pick rate each year. Conversely, taking the same approach with RPI, only 61 percent of selections, on average, would have been correct.
However, because most bracket pools have an escalating scale of value in each subsequent round, it is important to note during that same time period, using the same criteria, BPI correctly picked 12 of 28 Final Four teams and 3 of 7 National Champions; RPI only picked 6 of 28 correct Final Four teams and zero National Champions.
Note: BPI data before 2012 was unofficial.
Use BPI Win Your Bracket Challenge
Once the NCAA Men’s Basketball Tournament brackets are released on Sunday night, the ESPN Stats and Information team will breakdown the entire field according to the BPI, including snubs and over/under seeded teams. Later in the week, formal BPI projections which will show the percentage each team has to advance throughout the tournament will be released. Continue to check out ESPN.com/BPI throughout the tournament for information.