KRACH Ratings

[Eeyore]

Re: KRACH Ratings

That explanation of strength of schedule reinforces my point that KRACH is opaque rather than refuting it. Sure, you can dig through the math and a few people will be able to figure it out, but that doesn't help the average fan. This is exacerbated by giving a number that is called "Strength of Schedule", but really isn't. To be transparent requires more than the creators providing an explanation that would allow you, with a significant time investment, replicate the results. It has to be readily understandable by the people using it or trying to draw information from it. KRACH just doesn't meet that standard.

I agree with you that KRACH is the best of the ranking systems we have. I also suspect that there is no way to structure a rating system such that it both does the job sufficiently and is transparent to the average fan. Rutter requires some knowledge of Bayesian statistics. I really don't know anything about CHODR. Faced with that trade-off, I'd much rather go with the approach that is opaque rather than the one that's fatally flawed, but that doesn't mean denying the drawbacks that KRACH has. One of them is that most people are going to look at it and not really grasp where it comes from, though dropping the strength of schedule column, or at least renaming it, ought to be a no brainer that no one seems to care enough to do.

The real question about KRACH is how well it actually predicts results. Setting up a test of that is conceptually easy, but really time consuming to actually do. I might get around to it at some point.

[Eeyore]

Re: KRACH Ratings

i've seen many, many cases where team A and B play similar schedules....maybe team "A" is given a higher rank based on SOS...but then team B beats team A...once or maybe twice...but they are ranked lower. Sorry, but that's just stupid.

No, it really isn't. Each team plays more than one opponent, and allowing just a single game to determine your rankings when you have a wealth of additional data is what is dumb. As I said, if the results of a single head-to-head match up were really that determinative, we wouldn't see weekend series get split. We have actual evidence on this question, and it does not support your thesis.

[bearcat]

Re: KRACH Ratings

No, it really isn't. Each team plays more than one opponent, and allowing just a single game to determine your rankings when you have a wealth of additional data is what is dumb. As I said, if the results of a single head-to-head match up were really that determinative, we wouldn't see weekend series get split. We have actual evidence on this question, and it does not support your thesis.

Yes, actually it is...the system is a Very poor predictor of actual results when these team get to settle it out on the ice, rather than some nerd's computer. Sorry, but I've seen it happen for years.

[TonyTheTiger20]

Re: KRACH Ratings

That explanation of strength of schedule reinforces my point that KRACH is opaque rather than refuting it. Sure, you can dig through the math and a few people will be able to figure it out, but that doesn't help the average fan. This is exacerbated by giving a number that is called "Strength of Schedule", but really isn't. To be transparent requires more than the creators providing an explanation that would allow you, with a significant time investment, replicate the results. It has to be readily understandable by the people using it or trying to draw information from it. KRACH just doesn't meet that standard.

I agree with you that KRACH is the best of the ranking systems we have. I also suspect that there is no way to structure a rating system such that it both does the job sufficiently and is transparent to the average fan. Rutter requires some knowledge of Bayesian statistics. I really don't know anything about CHODR. Faced with that trade-off, I'd much rather go with the approach that is opaque rather than the one that's fatally flawed, but that doesn't mean denying the drawbacks that KRACH has. One of them is that most people are going to look at it and not really grasp where it comes from, though dropping the strength of schedule column, or at least renaming it, ought to be a no brainer that no one seems to care enough to do.

The real question about KRACH is how well it actually predicts results. Setting up a test of that is conceptually easy, but really time consuming to actually do. I might get around to it at some point.

I hear you. I think, though, that KRACH itself is pretty transparent and intuitive. Strength of schedule maybe not, but the ratings, definitely. The average fan doesn't have to understand the step by step mathematical process to derive the numbers to understand what it's doing.

It's like calculus -- you don't need to know how to calculate a derivative to understand that you're just trying to find the slope at a point on a curve.

[TonyTheTiger20]

Re: KRACH Ratings

some nerd's computer

YES!!! I'm glad we just came right out with it.

[ARM]

Re: KRACH Ratings

It's really something of a multiplicative factor.

I agree; it would be better if they called it something like "Schedule Factor", so people wouldn't use it to conclude, "Team A has played the toughest schedule in the country."

[TonyTheTiger20]

Re: KRACH Ratings

For fun I wanted to see how the KRACH ratings look if you include only games in the 2nd half. I realize there are flaws to this (fewer OOC games, for one) but still.

The result is a ranking pretty close to what you have over the course of the full year with a few exceptions.

1 Boston College 4108.74
2 Minnesota 2918.11
3 Wisconsin 1116.22
4 Clarkson 1002.95
5 Quinnipiac 721.91
6 Northeastern 562.40
7 Princeton 283.01
8 Colgate 278.44
9 Syracuse 220.90 ??????????????????????????????????
10 Harvard 213.66
11 Mercyhurst 196.16
12 St. Lawrence 188.55
13 North Dakota 180.30
14 Bemidji State 164.45
15 Boston University 151.47
16 Connecticut 108.35
17 Rensselaer 103.38
18 Cornell 102.36
19 St. Cloud State 84.61
20 Minnesota-Duluth 83.64

Look at UConn too hanging out around league average.

[TonyTheTiger20]

Re: KRACH Ratings

In other news, as further evidence that KRACH's "strength of schedule" label makes no sense, BC's 2nd half "strength of schedule" is 13th in the country. But, if NU had beaten BU in their 2nd to last game of the regular season, BC's SOS would have been 3rd.

That makes less than zero sense.

[gojackets]

Re: KRACH Ratings

KRACH also has the great property that winning will ALWAYS help your rating and losing will ALWAYS hurt your rating. That is, there are no "bad wins" like in RPI.

No matter how bad the team is that you're playing, your expected winning percentage will always be less than 1. So a win will always add more wins to your win total (1) than your chance of winning the game (like BC has a 0.997-ish chance of beating Union, for example), increasing their rating.

Same with losing -- losing will always lower your rating. Union losing to BC will always add fewer wins to Union's win total (0) than their chances of winning the game (0.003-ish), lowering their rating.

It also gives you a method to see what the percent chance team A has of beating team B: (Team A)/(Team A + Team B).

It's seriously fantastic and digging into it was one of the most interesting things I've ever done because I'm a raging nerd.

Can you now tackle the D3 women's Krach ratings. I'm trying to figure out how much is added to the eastern teams strength of schedule for solely being east of Michigan