John t whelan ranking simulator

[Numbers]

Re: John t whelan ranking simulator

I think you messed up the winning percentage potential. You take the total possible points to be had given the circumstance, and the weighting still follows the original paradigm that you described. The potential is 5 home wins (4.0) + 1 tie (1.0; doesn't matter where it was for a tie) + 3 away wins (3.6) + 1 road loss (0.8) = 9.4, not the 9.6 that you talked about previously. That should help your numbers a bit.

Thanks. I wondered about that. However, it still doesn't match what your calculator says. It would be a win% of .851 where your calculator gets .850 (I know that's miniscule, but it still indicates to me something different happening- maybe the win% on your program is without the weighting). And, the bonus doesn't come out right, either. I calculate a QWB of .915, whereas your calculator lists it as .98.

Not picking, just trying to see what is happening.

Thanks, FlagDude.

One thing that comes to mind - this is a very complicated calculation, and it depends on interpretation in some ways?

 

[FlagDUDE08]

Re: John t whelan ranking simulator

Thanks. I wondered about that. However, it still doesn't match what your calculator says. It would be a win% of .851 where your calculator gets .850 (I know that's miniscule, but it still indicates to me something different happening- maybe the win% on your program is without the weighting). And, the bonus doesn't come out right, either. I calculate a QWB of .915, whereas your calculator lists it as .98.

Not picking, just trying to see what is happening.

Thanks, FlagDude.

One thing that comes to mind - this is a very complicated calculation, and it depends on interpretation in some ways?

The .850 vs. .851 sounds like rounding vs. truncation in terms of display. The application stores the full decimal, but only outputs the first three places; I assume Java truncates instead of rounds. Also, when you are calculating the Quality Wins Bonus, are you taking into account the games that were removed in negative effect on the RatingsPI? One new feature with the 0.4 version is it left in a debug statement that when you select a team, it will tell you what games have been removed in the command line. Obviously you'll need to run from the command line instead of the .exe in order to get this.

 

[Numbers]

Re: John t whelan ranking simulator

The .850 vs. .851 sounds like rounding vs. truncation in terms of display. The application stores the full decimal, but only outputs the first three places; I assume Java truncates instead of rounds. Also, when you are calculating the Quality Wins Bonus, are you taking into account the games that were removed in negative effect on the RatingsPI? One new feature with the 0.4 version is it left in a debug statement that when you select a team, it will tell you what games have been removed in the command line. Obviously you'll need to run from the command line instead of the .exe in order to get this.

Oh. Well, that works for me, then. Likely the Mercyhurst game is removed, so that leaves 8.6 bonus Pts and 8.6 games, so that is close enough to a rounding error to work for me.

But, like I said, all those levels make a very complicated calculation. And, things are not quite so perfectly spelled out - the press release doesn't specify whether or not to leave out negative impact games. Again, not nitpicking, but noticing that this calculation of "RPI" with all it's new definitions, is conceptually easy: We need to include strength of schedule, too, so let's do that. But, then it gets complicated with all the tweaking....

 

[FlagDUDE08]

Re: John t whelan ranking simulator

Oh. Well, that works for me, then. Likely the Mercyhurst game is removed, so that leaves 8.6 bonus Pts and 8.6 games, so that is close enough to a rounding error to work for me.

But, like I said, all those levels make a very complicated calculation. And, things are not quite so perfectly spelled out - the press release doesn't specify whether or not to leave out negative impact games. Again, not nitpicking, but noticing that this calculation of "RPI" with all it's new definitions, is conceptually easy: We need to include strength of schedule, too, so let's do that. But, then it gets complicated with all the tweaking....

What sort of strength of schedule would you like to see? I thought about trying to calculate KRACH, but didn't have a formula. Not to mention, those SoS calculations are effectively meaningless, unless you use it as a predicting tool to see who is likely to beat a certain team, something that the PWR is, in effect, designed to do.

 

[Numbers]

Re: John t whelan ranking simulator

What sort of strength of schedule would you like to see? I thought about trying to calculate KRACH, but didn't have a formula. Not to mention, those SoS calculations are effectively meaningless, unless you use it as a predicting tool to see who is likely to beat a certain team, something that the PWR is, in effect, designed to do.

Sorry, not clear in my post. I was thinking about the committee and their definition. I obviously spent awhile looking at the press release, trying to figure out how to calculate, and it wasn't perfectly clear.

My remark about SoS was from the committee's perspective. They know they need a SoS factor somewhere, because the schedules aren't balanced. Thus the birth of RatingsPI. And, the idea of coupling win%, oppwin%, and oppoppwin% seems 'right' and it's fairly easy to calc. Then, with removing negative impact games, and the QWB, and the home/road factor (and I see the justification for all of them - it's good), the calc just gets more and more complex. Witness a guy like Patman who is a programmer, and he claims the minutiae gives him indigestion.

It was just a comment on my part.

By the way, I can send you a spreadsheet for KRACH this week if you want. I made one a couple years ago for NHL, and for NCAA it would just need expanding. Since I am not a programmer (46 years old, wanted to do what Whelan does, but ended up in the ministry, so I didn't keep up with all the new languages), I just do every thing the tedious way - Excel will calculate KRACH - you just have to do the iterations manually.

 

[JimDahl]

Re: John t whelan ranking simulator

While there were a lot of little details to get right, I think the only one where it's not fairly obvious what the NCAA intended is whether the removal of an adverse impact win from the index affects the QWB. Based on the language of the memo, my guess was that the QWB is a separate step from the calculation of the index, so you would still get it for wins excluded from the RPI calculation. I wouldn't be least bit surprised to turn out to be wrong, though.

 

[Numbers]

Re: John t whelan ranking simulator

While there were a lot of little details to get right, I think the only one where it's not fairly obvious what the NCAA intended is whether the removal of an adverse impact win from the index affects the QWB. Based on the language of the memo, my guess was that the QWB is a separate step from the calculation of the index, so you would still get it for wins excluded from the RPI calculation. I wouldn't be least bit surprised to turn out to be wrong, though.

Thanks for joining us Jim. I will copy the relevant part of the memo:
Once the total bonus points have been calculated they are divided by the total weighting of all games played per the RPI calculation (with road wins/home losses weighted with a factor of 1.2 and home wins/road losses weighted with a factor of 0.8). The resulting Quality Wins Bonus (QWB) is added to the original RPI to obtain the final RPI for each team. This is the value to be used in comparing any two teams, along with the other selection criteria.

Now, there are 2 parts:
1 question is: would you still get QWB from a removed game? This seems a bit irrelevant, seeing that any win against a team with a high enough RPI to get QWB pts won't be removed, so

moving on to 2) It seems you add all the QWB pts, and then divide by a #ofgames calculation. Obviously, the home/road weighting is in effect with this calculation. The part not spelled out is: Do you count games that were removed from the RPI calculation because of neg effect even though you won?

As an example, Minny has a win against Mercyhurst which is removed from the sched when calculating RPI. Do you count 0.8 for that game when deciding what number to divide the QWB by?

This is the question, and the answer does not seem to be explicit.

 

[FlagDUDE08]

Re: John t whelan ranking simulator

Sorry, not clear in my post. I was thinking about the committee and their definition. I obviously spent awhile looking at the press release, trying to figure out how to calculate, and it wasn't perfectly clear.

My remark about SoS was from the committee's perspective. They know they need a SoS factor somewhere, because the schedules aren't balanced. Thus the birth of RatingsPI. And, the idea of coupling win%, oppwin%, and oppoppwin% seems 'right' and it's fairly easy to calc. Then, with removing negative impact games, and the QWB, and the home/road factor (and I see the justification for all of them - it's good), the calc just gets more and more complex. Witness a guy like Patman who is a programmer, and he claims the minutiae gives him indigestion.

It was just a comment on my part.

By the way, I can send you a spreadsheet for KRACH this week if you want. I made one a couple years ago for NHL, and for NCAA it would just need expanding. Since I am not a programmer (46 years old, wanted to do what Whelan does, but ended up in the ministry, so I didn't keep up with all the new languages), I just do every thing the tedious way - Excel will calculate KRACH - you just have to do the iterations manually.

Speaking as a programmer who has difficulty with calculations in OpenOffice (heck, the macro I had to set up to even get the schedule from the summer to the state it is in for the application was difficult enough), I can understand where you're coming from.

I have never seen interpretation when it comes to mathematics, and is why I enjoy it so much. The only place where I see interpretation is in translation, specifically when trying to explain it to the "I was told there'd be no math..." folk. The NCAA did a fairly decent job in the explanation, although there seems to be some holes. I don't know if the selection committee members would be able to shed some light (RPI's Col. Knowlton is on the committee, but I don't know how much they're allowed to say).

 

[JimDahl]

Re: John t whelan ranking simulator

Agreed. You're quite right, of course, that the impact of that decision would be in the divisor. "the total weighting of all games played per the RPI calculation" just isn't clear. Like I said, my guess when I implemented this was to use the complete weighted games played (including the adverse wins) only because they structure of the memo really made the QWB seem like a completely separate step from the RPI. But, the "per the RPI calculation" language could very well mean dropping the adverse wins.

 

[Numbers]

Re: John t whelan ranking simulator

Speaking as a programmer who has difficulty with calculations in OpenOffice (heck, the macro I had to set up to even get the schedule from the summer to the state it is in for the application was difficult enough), I can understand where you're coming from.

I have never seen interpretation when it comes to mathematics, and is why I enjoy it so much. The only place where I see interpretation is in translation, specifically when trying to explain it to the "I was told there'd be no math..." folk. The NCAA did a fairly decent job in the explanation, although there seems to be some holes. I don't know if the selection committee members would be able to shed some light (RPI's Col. Knowlton is on the committee, but I don't know how much they're allowed to say).

The cool thing would be to ask Knowlton and see. If he says "Sorry, I can't divulge that." then fine. Otherwise, if he says, then we know for sure that the removed games either are or are not counted in the divisor for the QWB bonus.

I will work up this KRACH Spreadsheet for you. It will take me a little time, though. I just checked, and I still have the spreadsheet I made earlier. If you have looked at any explanations, you know that KRACH requires iteration, and in my Excel sheet, you have to do that manually. Btw, I only have Excel2003. Like I say, this is a hobby, because I like Numbers.

In general, I like both the home/away weighting idea and the QWB that grades down through the RPI listing - with no TUC component. It should make it impossible for a team to theoretically gain by losing.

 

[goblue78]

Re: John t whelan ranking simulator

It should make it impossible for a team to theoretically gain by losing.

Just to point out that it will always be possible (if not necessarily likely) to gain by losing. To take a simple example, suppose in the last game of the regular season a win gives you a bye in the first round of the playoffs while a loss makes you play a first round series. And assume you don't win the conference championship and get an autobid. By losing, you have the chance to go 5-1 in the playoffs (I'm thinking of the ECAC here, but other conferences work similarly) but by winning you can at best go 3-1 because of the first round bye. Those extra two wins might more than compensate for the last game loss. (It was even worse when the league had a third-place game, but no league does that now). The basic point is that the number of games you can win may be favorably affected by losing a game.

It would also be possible to lose a late game to boost your opponent into QWB bonus territory. You might then get points from earlier games against them in their rink. Even if it doesn't compensate for the loss, you might also knock someone else out of the QWB pool whom your opponent for a spot beat a couple of times on the road. So theoretically, at least, this system doesn't force you to always do better by winning. And it certainly doesn't do so if you're worried about seeding in the NCAAs, not just whether or not you get in.

 

[FlagDUDE08]

Re: John t whelan ranking simulator

Just to point out that it will always be possible (if not necessarily likely) to gain by losing. To take a simple example, suppose in the last game of the regular season a win gives you a bye in the first round of the playoffs while a loss makes you play a first round series. And assume you don't win the conference championship and get an autobid. By losing, you have the chance to go 5-1 in the playoffs (I'm thinking of the ECAC here, but other conferences work similarly) but by winning you can at best go 3-1 because of the first round bye. Those extra two wins might more than compensate for the last game loss. (It was even worse when the league had a third-place game, but no league does that now). The basic point is that the number of games you can win may be favorably affected by losing a game.

It would also be possible to lose a late game to boost your opponent into QWB bonus territory. You might then get points from earlier games against them in their rink. Even if it doesn't compensate for the loss, you might also knock someone else out of the QWB pool whom your opponent for a spot beat a couple of times on the road. So theoretically, at least, this system doesn't force you to always do better by winning. And it certainly doesn't do so if you're worried about seeding in the NCAAs, not just whether or not you get in.

And sometimes, it is best to go down to a weaker opponent than to move on and face an opponent that will severely weaken your chances, such as when RPI lost to Colgate in 2011; they would have had to face Cornell had they won.

 

[Patman]

The .850 vs. .851 sounds like rounding vs. truncation in terms of display. The application stores the full decimal, but only outputs the first three places; I assume Java truncates instead of rounds. Also, when you are calculating the Quality Wins Bonus, are you taking into account the games that were removed in negative effect on the RatingsPI? One new feature with the 0.4 version is it left in a debug statement that when you select a team, it will tell you what games have been removed in the command line. Obviously you'll need to run from the command line instead of the .exe in order to get this.

I'd be careful about blaming rounding... If an error is buried enough it can look like precision error vs human error

 

[Patman]

The cool thing would be to ask Knowlton and see. If he says "Sorry, I can't divulge that." then fine. Otherwise, if he says, then we know for sure that the removed games either are or are not counted in the divisor for the QWB bonus.

I will work up this KRACH Spreadsheet for you. It will take me a little time, though. I just checked, and I still have the spreadsheet I made earlier. If you have looked at any explanations, you know that KRACH requires iteration, and in my Excel sheet, you have to do that manually. Btw, I only have Excel2003. Like I say, this is a hobby, because I like Numbers.

In general, I like both the home/away weighting idea and the QWB that grades down through the RPI listing - with no TUC component. It should make it impossible for a team to theoretically gain by losing.

Spreadsheet? I may as well start drinking now.

Edit: I will get around to this during my Christmas break. Home should be boring enough to make appropriate changes. If FD is the new easy way for a game record I'll lean on him.

Edit #2: Dahl, I assume the game value is still relevant towards deletion... This stuff makes it needlessly complicated and as usual I like running Monte Carlo runs.

FD, how are you computing?

 

[FlagDUDE08]

Re: John t whelan ranking simulator

I'd be careful about blaming rounding... If an error is buried enough it can look like precision error vs human error

I'm well aware of this. However the winning percentage calculation, which we were discussing, is not complex enough for this to be the case. If we were talking about something such as OWP or OOWP, also the quality wins bonus, I am quite sure that this could be a programming or calculation error.

 

[FlagDUDE08]

Re: John t whelan ranking simulator

Spreadsheet? I may as well start drinking now.

Edit: I will get around to this during my Christmas break. Home should be boring enough to make appropriate changes. If FD is the new easy way for a game record I'll lean on him.

Edit #2: Dahl, I assume the game value is still relevant towards deletion... This stuff makes it needlessly complicated and as usual I like running Monte Carlo runs.

FD, how are you computing?

I wrote a Java application with various methods to do each portion of the calculation.

 

[Patman]

I'm well aware of this. However the winning percentage calculation, which we were discussing, is not complex enough for this to be the case. If we were talking about something such as OWP or OOWP, also the quality wins bonus, I am quite sure that this could be a programming or calculation error.

I wasn't reading closely . to me round at 3 places is round at 3 places

 

[Numbers]

Patman, I am very aware that a spreadsheet is slow. I have no access to anything faster, and no skill. I offered because Flag seemed unsure how to calculate, and a spreadsheet for KRACH would be instructive in some ways. As you know, KRACH calculates differently. I think it is an easier calculation than all the minutiae involved in the current pairwise.

If you want to work up a KRACH calculator, too great!!!

 

[Patman]

Patman, I am very aware that a spreadsheet is slow. I have no access to anything faster, and no skill. I offered because Flag seemed unsure how to calculate, and a spreadsheet for KRACH would be instructive in some ways. As you know, KRACH calculates differently. I think it is an easier calculation than all the minutiae involved in the current pairwise.

If you want to work up a KRACH calculator, too great!!!

It's not that it's slow, it's that it's painful

 

[FlagDUDE08]

Re: John t whelan ranking simulator

It's not that it's slow, it's that it's painful

Especially once you start getting into macros.