TonyTheTiger20

03-07-2017, 08:33 AM

Remember a couple years ago when I tried my hand at building a computer ranking system?

http://board.uscho.com/archive/index.php/t-111945.html

It was fun to build, but it was pretty rudimentary and had a lot of flaws (for example, all losses were treated the same by the system regardless of how good the team you beat was.

I started over from scratch and gave it another go, and I am thrilled with what I have. Everybody welcome back the brand new GRaNT (Grant's Reasonable and Not Terrible) Computer Rankings!

Think of it as essentially KRACH for margin of victory. But instead of margin of victory, what's used is the percentage of goals each team scores in each game (i.e. if you win 3-1, you scored 75% of the goals in the game). The ratings are set such that if you add up the sum of the actual G%'s for each team, it equals the expected G% against each team. It is calculated the same way KRACH is in that you set each team's rating equal to 100, run through the calculations, get a new rating, and then run that new rating through the calculations, over and over until the ratings for each team don't change after successive runs.

It avoids messy problems with shutouts (i.e. even though a 1-0 win and a 5-0 win both have 100% of goals scored in each game) by dealing with the season as a whole instead of individually. So, for example, if Team A wins its two games 1-0 and 3-1, its combined G% will be 4 out of 5 goals = 80%, and if Team B wins its two games 5-0 and 3-1, its combined G% will be 8 out of 9 goals = 89%.

Some more details and a full ranking of teams for both men's and women's hockey can be found here: http://www.bcinterruption.com/boston-college-hockey/2017/3/7/14839436/2016-2017-ncaa-mens-and-womens-college-hockey-grant-computer-rankings

Here's a screenshot of the women's rankings after the conference tournaments below.

All feedback and criticism are welcome!

<a href="http://www.bcinterruption.com/boston-college-hockey/2017/3/7/14839436/2016-2017-ncaa-mens-and-womens-college-hockey-grant-computer-rankings">

<img src="http://i.imgur.com/mHKnvty.png" alt="Click here to go to the GRaNT Computer Rankings!" height="500">

</a>

http://board.uscho.com/archive/index.php/t-111945.html

It was fun to build, but it was pretty rudimentary and had a lot of flaws (for example, all losses were treated the same by the system regardless of how good the team you beat was.

I started over from scratch and gave it another go, and I am thrilled with what I have. Everybody welcome back the brand new GRaNT (Grant's Reasonable and Not Terrible) Computer Rankings!

Think of it as essentially KRACH for margin of victory. But instead of margin of victory, what's used is the percentage of goals each team scores in each game (i.e. if you win 3-1, you scored 75% of the goals in the game). The ratings are set such that if you add up the sum of the actual G%'s for each team, it equals the expected G% against each team. It is calculated the same way KRACH is in that you set each team's rating equal to 100, run through the calculations, get a new rating, and then run that new rating through the calculations, over and over until the ratings for each team don't change after successive runs.

It avoids messy problems with shutouts (i.e. even though a 1-0 win and a 5-0 win both have 100% of goals scored in each game) by dealing with the season as a whole instead of individually. So, for example, if Team A wins its two games 1-0 and 3-1, its combined G% will be 4 out of 5 goals = 80%, and if Team B wins its two games 5-0 and 3-1, its combined G% will be 8 out of 9 goals = 89%.

Some more details and a full ranking of teams for both men's and women's hockey can be found here: http://www.bcinterruption.com/boston-college-hockey/2017/3/7/14839436/2016-2017-ncaa-mens-and-womens-college-hockey-grant-computer-rankings

Here's a screenshot of the women's rankings after the conference tournaments below.

All feedback and criticism are welcome!

<a href="http://www.bcinterruption.com/boston-college-hockey/2017/3/7/14839436/2016-2017-ncaa-mens-and-womens-college-hockey-grant-computer-rankings">

<img src="http://i.imgur.com/mHKnvty.png" alt="Click here to go to the GRaNT Computer Rankings!" height="500">

</a>