Explaining College Hockey’s Pairwise Ranking System And How It Could Impact Other Sports
Penn State men’s hockey currently sits at No. 12 in NCAA hockey’s Pairwise rankings. There’s still a lot of hockey left to be played, but the Nittany Lions would qualify for the NCAA Tournament with an at-large bid if the season ended today, as the top 16 teams in the Pairwise at the end of the season qualify.
Although the NCAA does not officially use the Pairwise to make up its tournament field, the rankings made by the Pairwise have accurately predicted which teams made the tournament at season’s end in every season since the 2013-14 campaign. How does the Pairwise system work so accurately, and what implications could the Pairwise have in other NCAA sports?
In simplest terms, the Pairwise system takes three factors and uses comparisons to determine which team is the best in college hockey. The system uses each team’s Ratings Percentage Index (RPI), records against common opponents, and head-to-head wins to make a comparison between teams. If a team won an overall comparison of these three factors, they are awarded a point in the Pairwise standings. Since there are 60 teams in Division I hockey, the maximum amount of points a team can get is 59.
Penn State currently has 48 points in the Pairwise, which means that the team wins 48 out of 59 comparisons with all of the other teams in college hockey. The Nittany Lions are ranked above, for example, No. 15 Michigan, because they hold a 3-1 advantage in the Pairwise comparisons.
The sum of Penn State’s win percentage against common opponents is greater than that of Michigan’s and the Nittany Lions hold a better record against common opponents than the Wolverines. These account for two of Penn State’s three points with the last one coming from the team’s overtime victory in October. Michigan’s single point comes from its victory over the Nittany Lions at Pegula Ice Arena.
In contrast, Penn State loses the Pairwise comparison to Ohio State 3-2 despite winning its season series over the Buckeyes. The Nittany Lions receive two points in the Pairwise for their victories on December 2 and January 12, but Ohio State wins a point for having a higher win percentage over common opponents and a better record against them on top of its 5-1 victory on January 13.
When all of the Pairwise comparisons end in a tie, each team’s individual RPI is used as the main tiebreaker. Penn State’s comparisons with No. 13 Northeastern and No. 14 Minnesota-Duluth each end in 1-1 ties; both of those teams boast a better record against common opponents than Penn State. However, the one point for the Nittany Lions in each of those comparisons is earned through their higher RPI, giving them the advantage and, therefore, a higher ranking.
The Pairwise system is relatively clear and easy to follow once you understand how it works, but it is really only used prominently in college hockey. What if the NCAA adopted this format in place of the current College Football Playoff system seen on the gridiron today or on the hardwood for the basketball tournaments?
Implementing the Pairwise into NCAA football and basketball is a lot easier said than done due to the high volume of teams in each of those sports. There are 128 FBS football teams and 351 Division I basketball teams as opposed to the modest 60 found in college hockey, but the Pairwise doesn’t necessarily have to include every single team in each sport.
Teams with RPI ratings of under .500 were excluded from college hockey’s Pairwise rankings until the 2013-14 seasons, so excluding the weaker teams in football and basketball could be feasible. 81 teams finished with bowl-eligible records in 2017, so perhaps implementing a system similar to that of pre-2013 college hockey is feasible for football.
The current CFP system is completely based on the opinion of one committee of “experts.” While that collective opinion is probably based on factors like records against common opponents, why not let the numbers have a bigger say in who qualifies for the College Football Playoff? Would Penn State have made it into the four-team playoff ahead of Washington and/or Ohio State in 2016 if a Pairwise comparison system was in place?
If you feel hesitant about a system of numbers determining college football’s playoff system, remember that the Pairwise system in hockey is not the official ranking system that the NCAA uses, but instead is an accurate predictor of who will qualify for the NCAA tournament. A Pairwise system could perhaps impact the CFP members’ opinions on who should qualify for the playoff, but it would not definitively say who is in and who comes up short.
Adding a Pairwise comparison method would, at the very least, give the CFP committee a valuable resource in determining who deserves to play for the national title in early January.
As for basketball, the RPI is already a big part of determining the 68-team tournament field, so adding Pairwise comparisons to the mix could potentially be a seamless transition. The term “Bracketology” exists and is widely used towards the end of February and beginning of March when experts and analysts spend hours trying to decide who makes it to the big dance. Would the Pairwise spare “Bracketologists” the effort of trying to formulate the last four teams in the NCAA tournament every year?
For now, the NCAA is going to stick with its four-team CFP and 68-team March Madness formats that have worked well in the past and captured the hearts and attention of sports fans across the United States, but implementing a Pairwise system at the very least warrants a discussion.