Projecting the Final Hockey East Standings Using KRACH

Posted by: Mike McMahon

At College Hockey News, we endorse the KRACH ratings as the best way to compare college hockey teams. The KRACH stands for “Ken’s Ratings For American College Hockey,” and it was first applied to college hockey by statistician Ken Butler, hence the name.

Butler uses a mathematical model known as the Bradley-Terry rating system.

From our CHN explanation page on the KRACH:

“Getting a bit more technical: The Bradley-Terry system is based on a statistical technique called logistic regression, in essence meaning that teams’ ratings are determined directly from their won-loss records against one another. KRACH’s strength of schedule component is calculated directly from the ratings themselves, which is a key point. It means that KRACH, unlike many ratings (including RPI), cannot easily be distorted by teams with strong records against weak opposition.

The ratings are on an odds scale, so if Team A’s KRACH rating is three times as large as Team B’s, Team A would be expected to amass a winning percentage of .750 and Team B a winning percentage of .250 if it played each other enough times. The correct ratings are defined such that the “expected” winning percentage for a team in the games it’s already played is equal to its “actual” winning percentage.”

Using these values, I’ve come up with a projected final standings for Hockey East, and I’ll continue to update this on a weekly basis through the end of this season. We can also determine relative strength of schedule for each Hockey East team using these values.

Here’s how I applied these numbers:

— First, I took the KRACH value for each individual Hockey East team, and compared it to their opponents’ on a game-by-game basis. By doing this, we we able to determine an expected win percentage for each team. In my projection, I took this expected win percentage as percentage of a game won. For example, this weekend Merrimack plays two games against Boston College. BC’s KRACH value is 483.4 and Merrimack’s is 67.0, meaning that the Eagles would be expected to post a winning percentage of .888 against Merrimack. Therefore, we awarded Boston College 88.8 percent of a win in both of those games, or 1.76 of a possible two points. So out of this weekend, Boston College was awarded 3.52 points and Merrimack 0.48 points. I did this for every Hockey East game for the remainder of this season.

— Also, we took the average opponent KRACH value for each team, and were able to determine a remaining strength of schedule for each Hockey East team.

Based on the KRACH, here is how we can project the final Hockey East standings:

Screen Shot 2016-02-08 at 10.56.29 AM

Northeastern is the team we can project to take the biggest leap from its current standing, and that’s due to playing, by far, the easiest schedule remaining (you will see that table in a moment).

Based on these projects, Boston College, Notre Dame, Providence and UMass Lowell will receive first-round byes. The rest of the Hockey East first round will look like this:

UMass @ Boston University; Maine @ Northeastern; Merrimack @ Vermont; Connecticut @ New Hampshire.

Here is a table that shows the remaining strength of schedule, with the easiest appearing at the top:

Screen Shot 2016-02-08 at 11.00.47 AM

 

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