What in the World Is NPI?
Image Courtesy: NCAA
NCAA HOCKEY’S NEW STATISTICAL RANKING SYSTEM EXPLAINED
WRITTEN BY JAMES BLENNAU
Let’s make one thing clear before I start. I have taken math courses up to AP Calculus AB, and college-level probability and data analysis. But, I remember pretty much none of it. So with that out of the way, here is a journalist’s explanation of the system that will replace the PairWise rankings in choosing tournament teams.
BEHIND THE NUMBERS
The most important elements considered in the rankings system are win percentage and strength of schedule. The starting values will be set at 25/75, with each committee able to adjust the ratio as necessary for the primary two stats. Strength of schedule will be calculated according to a team’s opponents’ average NPI rating.
Secondly, quality win bonuses are applied to teams above any ranking determined by the committee. This could be anywhere above 30, likely, considering the number of teams in NCAA hockey. For example, if Michigan Tech was ranked at 40 and beat Michigan, ranked at 15, when the margin for a quality win is 20, the difference of 25 between their rankings would be multiplied by whatever the multiplier is, in this case hypothetically .500, leading to a quality win bonus of 12.5 in its NPI ranking for the season.
Home and away weights will also be added to all games, which could be adjusted according to conference or non-conference matchups and overall by the selection committee. One example could be setting road wins at a 1.2x multiplier and home wins at 0.8. Overtime wins and losses will also be weighted differently according to the committee’s decision. It could look something like 0.25 win/0.75 loss for an overtime loss and vice versa for a win. This is also an optional addition, according to the NCAA’s latest published guidance to DIII teams.
All of the committee’s multiplier and modifier decisions have not been published by the NCAA, and are not guaranteed to be published at all, making our lives a whole lot more complicated following the tournament teams this year.
HOW DID WE GET HERE?
Well, the short answer is that ice hockey is a guinea pig. NPI has been used across NCAA DIII for a full season last year, but never at any other level. All DIII championships used the system last year, including ice hockey, but its impact hasn’t fully formed yet since it’s only been one season of selecting teams.
Administrators on the committee, led by Harvard Senior Associate Director of Athletics Tim Troville, will be free to weigh each statistic as they please, leaving fans and teams alike in the dark before the selection show this March.
PairWise rankings had been in use since 2013, but the initial goals of transparency and objectivity seem to be slipping. As more statistics become widely available, it’s become increasingly difficult to hide which teams are heading to the national stage, but the NPI system gives more power to those making the sport’s most important decisions to lead it into a new era of anticipation through to March 22nd.
