What's new
USCHO Fan Forum

This is a sample guest message. Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

  • The USCHO Fan Forum has migrated to a new plaform, xenForo. Most of the function of the forum should work in familiar ways. Please note that you can switch between light and dark modes by clicking on the gear icon in the upper right of the main menu bar. We are hoping that this new platform will prove to be faster and more reliable. Please feel free to explore its features.

2021-2022 PWR, KRACH, GRaNT, and other numbers

I've been without a laptop for over a month which has been pretty torturous, but I'm back in action and was finally able to publish my annual calculators.

One thing to keep in mind is that for some reason USCHO's PWR and mine are different. I can't figure out where I might be wrong, and historically it's been USCHO that's had the issue and not me... I'll be keeping an eye out for any bugs though.

I'm using 67% for an overtime win in the Pairwise. If we find out it's something different when the pre-champs manual comes out I'll switch it. I'm using a full win for an OT win in KRACH. GRaNT uses goals, not wins, so it's unaffected.

PWR: https://www.bcinterruption.com/bosto...rwise-rankings

KRACH: https://www.bcinterruption.com/bosto...ach-calculator

GRaNT: https://www.bcinterruption.com/bosto...puter-rankings
 
Last edited:
I'm using a full win for an OT win in KRACH and GRaNT.
Why? They only have 2/3 of the team out there, may as well only have it be worth 2/3 of a win if you're trying to figure out the relative strength of the teams.

Anyway, thanks for all of the time that you're putting into this. And I agree that it is likely USCHO's PairWise that is off, due to including RMU or some other team that shouldn't be included. History is on your side, as you've typically put more research into it.
 
Yeah I thought about it on the KRACH thing. My main reasons are that (1) the 2/3 thing is so arbitrary and I hate it (I mean men's is using a different number entirely), and (2) KRACH is basically measuring your ability to earn a result, regardless of how you do it (though I draw the line at shootouts).

Really it's just what I felt like is the less arbitrary and obnoxious. I think what I'm going to do is just add a feature where you can plug in whatever OT factor you want -- 100%, 67%, 55%, whatever -- and let it recalculate for the user that way. I probably would have done it already except with not having the laptop I just wanted to get them published ASAP haha And lastly, thanks!

PS I put above that I use a full win for GRaNT but that's not accurate, GRaNT is based on goals only, not wins. Edited to correct that.
 
Apparently you can't edit? God this forum is THE WORST lol
It is bad, but you can edit your own posts. Not sure why you could not.

Anyway, I do appreciate you putting the work in to resurrect your ratings. We have lost so many rankings (apparently) over the years, especially Rutter and Loch. It's great that you took the time to get all of yours flying again. Many thanks!

What I've never really understood, or maybe a better word is endorsed, regarding GRANT ratings is what you do with goal differential. Let's say that two teams with perfect records have each played 10 games. Team A won the first nine of those games by 1-0 shutouts, before winning one by a score of 2-1. Its ratio of goals scored versus goals allowed would be 11 to 1. Team B won all 10 of its games by 4-1 scores. Its ratio of goals versus goals allowed would be 40 to 10, or 4 to 1.

I don't remember for sure which way you make your assumption, but I think you said that a team with an 11 to 1 ratio is clearly superior to a team with a 4 to 1 ratio. As with most rankings, we're hampered in the hypothetical case above because we don't know anything about the caliber of competition, but I can argue that either Team A or Team B is stronger, depending on which point I'd like to make.

One way... Defense wins championships. A team that is allowing one goal through 10 games is going to be able to shut down its opponent and eventually will score. So Team A is clearly stronger.

Or ... Team B always has its games wrapped up by the final buzzer, while Team A is a bounce away from heading to OT. Hockey is a contest ultimately decided by relatively few plays, so not many bounces need to change to flip a result. For Team A, we're dependent on every bounce along the way. Team B has given itself a little more slack to survive some variance in its results. This suggests that Team B is stronger and in better shape moving forward.

We seldom see a team in women's D-I win a title when it doesn't have a great offense, and in particular, an offense that can score against strong competition. Wisconsin had great defensive teams in the ARD era, but its offense was more boa constrictor than cobra and had trouble delivering the lethal strike against top adversaries once we reached the "win or go home" point of the season.

It would be nice if a model included some dampening of the assumption that GRANT makes, allowing it to recognize a goal differential advantage in addition to a goal ratio advantage. For the A/B example above, it would be possible that Team A could have the same goals & goals allowed shown above for A and its opponents, but include a 2-0 win along with a 0-1 loss. That better highlights the vulnerability of Team A. Yes, goal ratio may matter, but I've seen nothing in my observations to convince me that it vastly outweighs goal differential. GRANT ignores that Team B has a goal differential of 30 while Team A has a goal differential of only 10. You can do all sorts of calculations from that point on, but if a fundamental assumption made early on is unsupported at best, and possibly even errant, there isn't any way to save the comparison.

I used to place the GRANT ratings alongside the other math-based models to see how it compares. Now, that Lock's WCHODR looks to be dormant, KRACH is about all that we have for comparison. RPI/PWR, for all of its attempts at tweaks and corrections over the years, is still about as fair as the federal income tax code.
 
One thing to keep in mind is that for some reason USCHO's PWR and mine are different. I can't figure out where I might be wrong, and historically it's been USCHO that's had the issue and not me... I'll be keeping an eye out for any bugs though.
[/url]

PWR is wrong so the committee can put the teams they want in the NCAA tournament rather than being bound by the math.
 
It is bad, but you can edit your own posts. Not sure why you could not.
The option to edit it is there for me but every time I click "Save" it reverts back... argh!

Anyway, I do appreciate you putting the work in to resurrect your ratings. We have lost so many rankings (apparently) over the years, especially Rutter and Loch. It's great that you took the time to get all of yours flying again. Many thanks!
I enjoy it! Lots of work to be done to build in the 11-team tournament changes in the bracket predictor for March... fortunately I've got some time haha

What I've never really understood, or maybe a better word is endorsed, regarding GRANT ratings is what you do with goal differential. Let's say that two teams with perfect records have each played 10 games. Team A won the first nine of those games by 1-0 shutouts, before winning one by a score of 2-1. Its ratio of goals scored versus goals allowed would be 11 to 1. Team B won all 10 of its games by 4-1 scores. Its ratio of goals versus goals allowed would be 40 to 10, or 4 to 1.

I don't remember for sure which way you make your assumption, but I think you said that a team with an 11 to 1 ratio is clearly superior to a team with a 4 to 1 ratio. As with most rankings, we're hampered in the hypothetical case above because we don't know anything about the caliber of competition, but I can argue that either Team A or Team B is stronger, depending on which point I'd like to make.
Yeah we've talked about this before. Part of the reason is that I like the diminishing returns you get for blowing out a team. Is a team that wins 10-0 that much better than a team that wins 8-0? Probably not. I do think that if you're shutting teams out week after week after week, there's something to be said there about your relative strength.

I would like to build a model that's off straight-up goal margin instead of goal ratio, but I've had some trouble doing it in the past... I couldn't get the values to converge in a way that KRACH and GRaNT do. I might give it another go one of these days though.

I used to place the GRANT ratings alongside the other math-based models to see how it compares. Now, that Lock's WCHODR looks to be dormant, KRACH is about all that we have for comparison. RPI/PWR, for all of its attempts at tweaks and corrections over the years, is still about as fair as the federal income tax code.
I like having GRaNT out there and I'm proud of it and I do think it has some value in determining relative strength between teams, but I still think KRACH is the gold standard. Of course, more is always better... I miss having Rutter and WCHODR out there even though I didn't have the background on how it was calculated.

KRACH, though, is mathematical art and has a total lack of arbitrariness. Fortunately KRACH will never go away! Not as long as I've got an Excel spreadsheet anyway.
 
One thing to keep in mind is that for some reason USCHO's PWR and mine are different. I can't figure out where I might be wrong, and historically it's been USCHO that's had the issue and not me... I'll be keeping an eye out for any bugs though

...

I'm using 67% for an overtime win in the Pairwise. If we find out it's something different when the pre-champs manual comes out I'll switch it.

I was able to confirm with a source at the NCAA that women's hockey is using 67% for 3v3 OT wins, which is distinct from the men who are using 55%. Also, it's 100% for 5v5 OT wins (i.e. in conference tournaments) and 50% for shootout wins & ties, which we already kind of knew but I got those confirmed anyway.

I was further able to confirm with the NCAA that my Pairwise numbers are right and USCHO's are wrong.
 
I was able to confirm with a source at the NCAA that women's hockey is using 67% for 3v3 OT wins, which is distinct from the men who are using 55%. Also, it's 100% for 5v5 OT wins (i.e. in conference tournaments) and 50% for shootout wins & ties, which we already kind of knew but I got those confirmed anyway.

I was further able to confirm with the NCAA that my Pairwise numbers are right and USCHO's are wrong.

Out of curiosity, what is the success ratio of GRaNT? I assume you track your predictions. I have noted with amusement when my teams have beaten your assessment.
 
Out of curiosity, what is the success ratio of GRaNT? I assume you track your predictions. I have noted with amusement when my teams have beaten your assessment.

That's a tough question to answer because over the long run, GRaNT will be perfect looking at goal ratio going "backwards," just like KRACH will be perfect looking backwards looking at wins/losses. (that is, by definition KRACH's expected wins and actual wins are exactly equal -- it's how the formula is actually defined).

Looking forward is just tougher because at some point you have to decide when you have enough results for the values to be meaningful. I think it would probably be possible to track GRaNT point spread predictions for the second half. I'd be interested in seeing how it works out (and honestly even more so for KRACH).
 
That's a tough question to answer because over the long run, GRaNT will be perfect looking at goal ratio going "backwards," just like KRACH will be perfect looking backwards looking at wins/losses. (that is, by definition KRACH's expected wins and actual wins are exactly equal -- it's how the formula is actually defined).

Looking forward is just tougher because at some point you have to decide when you have enough results for the values to be meaningful. I think it would probably be possible to track GRaNT point spread predictions for the second half. I'd be interested in seeing how it works out (and honestly even more so for KRACH).

I haven't done a comparison in a while but out of all the shots metrics I track, relative shots (pct. of shots taken vs. average pct. of opponents' shots allowed) and relative shots but only against teams that outshoot their opponents have correlated pretty well with overall wins and losses.

What's been most valuable is identifying contenders. I think in the years I've been tracking these stats (14-15 to present), only once has there been a champion that didn't outshoot their opponent by double digits AND have a double digit relative shots percentage.

For reference the top 3 this season are
OSU - +16.96% (takes 68.69% of shots in games, opponents allow 51.72%)
Colgate - +16.76% (66.06%, 49.30%)
Wisconsin - +15.95 (70.42%, 54.47%)
 
Back
Top