Onward State: Explaining College Hockey’s Pairwise Ranking System And How It Could Impact Other Sports

College hockey’s Pairwise ranking system gives fans a clear (if not complicated) picture of their team’s postseason aspirations. Would a similar system be good for college football and basketball?

Source: Explaining College Hockey’s Pairwise Ranking System And How It Could Impact Other Sports

HV Note: The author made a mistake in his article. He accurately noted the three criteria that the Pairwise uses: Ratings Percentage Index (RPI), record against common opponents, and head-to-head. But he incorrectly applied those criteria when he compared PSU with OSU and Michigan.

Let’s use PSU vs Michigan as an example to point out where he went wrong.
He correctly stated that Penn State earned a point because the sum of their win percentages against common opponents was greater than that of Michigan’s (3.625 vs 2.792). He correctly noted that Penn State and Michigan each earned a point for their wins when they split their series in Ann Arbor. But he went wrong when he did the third comparison. He said that PSU earned a point because their overall record against common opponents was better than Michigan. That’s a wrong comparison. The correct comparison, as he noted in the introduction, is RPI. Penn State earned their point because their RPI was higher than Michigan’s (.5493 to .5290). So PSU won the overall comparison 3 points to 1.

The result was correct, but the process was wrong.