(Photo: Kylee Meter/WCSN)
As Arizona State heads into next weekend’s series at No. 14 Princeton, the team delves deeper into unknown territory. Sitting on the cusp of a program-high 11 wins in season, while also sitting the top-20 (18th) for the first time ever, the eyes of fans and critics alike have turned to watch where the Sun Devils place in the rankings week in and week out, as they try to become the first independent program to qualify for the NCAA Men’s Hockey Tournament since 1992. However, no other ranking system is more important than the PairWise Rankings.
What is the PairWise system and why is it the ranking system to watch?
The PairWise Ranking system is the only ranking system that is based on the system used by the NCAA Selection Committee when deciding at-large-bids for the NCAA tournament (technically, the NCAA does make the ranking available but USCHO provides a replica ranking throughout the season). Currently, all six conference tournament champions get an automatic bid into the 16-team tournament. The remaining 10 teams are decided exclusively by the PairWise Rankings.
So, how is the PairWise formulated? With three factors, all of which are compared as a head-to-head statistic against every other DI hockey program. The first factor is a team’s record against common opponents. The second record is a team’s head-to-head record, and finally, a team’s RPI (Ratings Percentage Index). An advantage in one category represents a point, and a college with more points than another college will be placed higher in the PairWise ranking.
However, not every team will play each other, so to counteract this, if there is a tie as to where one college leads the common opponent category and another leads the RPI category, the RPI category acts as the tie-breaker. So, since most teams don’t play each other or share common opponents each year, the RPI is arguably the most important factor in the PairWise Rankings. Thus leads to the next question: What is the Ratings Percentage Index?
The Ratings Percentage Index
Strap on in, this is about to get weird (and mathematical). The RPI is a system also split into three distinct categories in its formulation. As per USCHO.com, 25% of the RPI score is calculated by a team’s personal winning percentage at any given time. The opponents each team faces plays a factor as well, as 21% of the RPI is calculated by its opponent’s (not collective) winning percentage. However, the biggest factor to RPI, actually goes toward a team’s opponents’ opponents’ winning percentage — basically, evaluating the schedule of each opponent on any team’s own schedule. A whopping 54% is dedicated to this single statistic. Similarly, the RPI incorporates bonuses for road wins, and quality wins over a top-20 team. Theoretically, if a college with a large RPI beats a college with a low RPI, the winning school’s RPI would actually drop. However, in its current state, a the RPI’s formula disregards these victories from its calculations. So yes, there are indeed “bad wins” in hockey… no matter what any coach may say.
Where does ASU currently sit?
As it currently stands, Arizona State sits ranked 11th in the nation in the PairWise ranking behind Denver, while sitting at 11th in the nation in the RPI standing. The team fell four positions in the PairWise from 7th to 11th after being swept on the road by Nebraska-Omaha. The team gets this week off to regroup and get ready for the challenging weekend that follows.
ASU would likely need to finish the season either in, or near, the top 10 in PairWise to qualify for the tournament, depending on which teams around the country earn automatic bids by winning their league.
“That’s the only ranking at the end of the day that matters,” Powers said. “Right now, it’s not even worth looking at…For now, it’s just the same focus. It’s focusing on what’s in front of us.”
