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Introducing the Men's & Women's Hockey GRaNT Computer Rankings

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A new ranking system for college hockey

BC Athletics

KRACH. Rutter. PWR. RPI. CHODR. WCHODR... And now, the GRaNT Computer Rankings.

It stands for Grant's Reasonable and Not Terrible Computer Rankings, it's our very own creation here at BCI, and it's the next big thing in college hockey.

The calculator is generated using an excel spreadsheet. It's pretty exciting stuff. If you'd like to play around, you can click here for the men's and women's sheets to download onto your computer. Note that there are a lot of hidden cells and tabs you'll want to unhide. You'll also need to enable circular references.

For anyone who has ever complained about how bad the Pairwise Rankings are at selecting the NCAA tournament, this is another computer ranking to stand alongside the classics like KRACH and CHODR.

The following involves math. Skip past the following section if that makes you uncomfortable.

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Here's the jist of the rankings:

-All teams are assigned an arbitrary rating. It doesn't matter what you use because the rankings will come out the same regardless of what you start with. Since it doesn't matter, the calculator literally starts each team out with a RAND() value.

-Each team's rating is recalculated based on their winning percentage and their opponent's rating as follows:
---A win adds the opponent's rating
---A loss adds zero
---A tie adds 1/2 the opponent's rating
------The sum is divided by the number of games played, and then adjusted to equal the percent of the average of the new ratings.

The GRaNT Rankings are constructed somewhat similarly to KRACH in that it uses each team's ranking to calculate everyone else's ranking. I'll explain.

Example: Teams A, B, and C each play each other once each.

Team A's starting rating: 0.666
Team B's starting rating: 0.444
Team C's starting rating: 0.222

Team A beats Team B and ties Team C. Team A's new unadjusted rating is (0.444+0.111)/2=0.278.

Team B beats Team C and loses to Team A. Team B's new unadjusted rating is (0.222+0)/2=0.111

Team C ties Team A and loses to Team B. Team C's new unadjusted rating is (0.333+0)/2=0.167

The average of the new ratings is (0.278+0.111+0.167)/3=0.185

So, each team's new rating is:

Team A: 0.278/0.185=1.503
Team B: 0.111/0.185=0.600
Team C: 0.167/0.185=0.902

Then the process repeats itself, recalculating based on the new ratings instead of the starting rating. Each team's rating will converge to a different number such that when you recalculate, you get the same number:

Team A: 0.6190/0.4491=1.3784 (percent of average)
Team B: 0.3837/0.4491=0.8544
Team C: 0.3446/0.4491=0.7673

Team A: (0.8544+0.38365)/2=0.6190
Team B: (0+0.7673)/2=0.3837
Team C: (0.6892+0)/2=0.3446

-- and those convergent values are each team's final rating.

That final rating is scaled to make zero equal average, and ranked, naturally, from best to worst. The result is the GRaNT Rankings.

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You'll notice that teams are awarded 0 points for a loss, no matter who they play -- that means that teams are not penalized for losing to good teams, since all losses count the same. The end result is that teams are rewarded for playing and beating good teams, not penalized for playing but losing to good teams.

It also means that teams are not overly penalized for bad losses. In this way, the ranking is more focused on how good your team can be, not how bad your team can be.

I feel that come tournament time, when teams are focused and playing at their highest level, this will be a better indicator for success than overly penalizing them for a couple of bad mid-season losses when not playing at their full potential.

The ranking is posted below for both Men's and Women's Division I college hockey. They will update periodically each week.

GRaNT Computer Rankings:
NCAA Division I Men's Hockey

GRaNT Computer Rankings:
NCAA Division I Women's Hockey