Originally posted by Patman
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John t whelan ranking simulator
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Re: John t whelan ranking simulator
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Originally posted by goblue78 View PostMy previous code was in fact a simulator. It simulates a season (including in-season and post-season tournaments) and calculates the NCAA field in under 1/7th of a second per simulation. The one thing it didn't do was implement the tie-breaking rules for conference playoffs. It just randomly seeded teams with tied conference records. Anyway, when I get around to it, I'll have to implement the new pairwise. By the time I do that, all the in-season tournaments will be over, so the simulation should be really fast.
Basic KRACH code is dead-simple, but implementing a home-road differential and a tie probability requires a maximum likelihood routine. Still not difficult, but a lot of the elegance goes away.
Interesting. I had thought about this and made my code recursive, though it was quite rare in simulations after the season was up that you needed more than one pass. (As I recall, it was something like one season in 30.) I guess i don't understand how it could not be recursive. If you don't make it recursive, can't a team protest that there was a game left in the games that counted to calculate RPI that lowered its rating?
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Re: John t whelan ranking simulator
Originally posted by Patman View PostI still say the end goal is a simulator
Basic KRACH code is dead-simple, but implementing a home-road differential and a tie probability requires a maximum likelihood routine. Still not difficult, but a lot of the elegance goes away.
Originally posted by JimDahl View PostA point of disagreement in the past has been whether this process is recursive. I've always been pretty convinced that they calculate RPI once, then drop all the games that make it go up if you drop them. Others have wondered if you then need to make another pass to see if the new, higher RPI, has pushed any new games into "adverse" territory (repeating until you don't find any). That matters a lot more this time of year than later, so I'm not sure we've ever had a conclusive test come tournament time.
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Re: John t whelan ranking simulator
Originally posted by Patman View PostI still say the end goal is a simulator
Basic KRACH code is dead-simple, but implementing a home-road differential and a tie probability requires a maximum likelihood routine. Still not diffocult, but a lot of the elegance goes away.
Originally posted by JimDahl View PostA point of disagreement in the past has been whether this process is recursive. I've always been pretty convinced that they calculate RPI once, then drop all the games that make it go up if you drop them. Others have wondered if you then need to make another pass to see if the new, higher RPI, has pushed any new games into "adverse" territory (repeating until you don't find any). That matters a lot more this time of year than later, so I'm not sure we've ever had a conclusive test come tournament time.
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Re: John t whelan ranking simulator
Originally posted by Patman View PostIf we are talking about a major website. Unlikely. I mostly meant amongst ourselves. In theory if one wanted to grab direct data then webscraping might be the best... Though painful.
One alternative would be to ask collegehockeystats to do a dump file for us with the most relevant summary (game data) info. But I don't know under whose auspices they produce game information.
If you wanted it to be a truly automated, trusted source, I think a high quality scraper/translator for collegehockeystats into a machine-readable input file is the way to go.
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Re: John t whelan ranking simulator
Originally posted by LynahFan View PostAbsolutely. When I wrote my KRACH script (is there any hockey fan who hasn't at least tried this?) in MATLAB, it was <100 lines of code, and the majority of that just had to do with reading the input file and stuffing the information into the win matrix, as you say. The actual "calculation" itself is like 10 lines of code - that simplicity is one of the aesthetic beauties of KRACH (in addition to its functional beauty).
A standard input format would be great, but you'd probably need all of the major sites (USCHO, CHN, etc) to come together to agree on it, and I'm not sure they'd be motivated enough to bother.
Standard input would be nice, but I agree that not many would. I know my input is entirely based upon the Google Docs spreadsheet that I put together over the summer that has the entire country's schedule.
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Originally posted by LynahFan View PostAbsolutely. When I wrote my KRACH script (is there any hockey fan who hasn't at least tried this?) in MATLAB, it was <100 lines of code, and the majority of that just had to do with reading the input file and stuffing the information into the win matrix, as you say. The actual "calculation" itself is like 10 lines of code - that simplicity is one of the aesthetic beauties of KRACH (in addition to its functional beauty).
A standard input format would be great, but you'd probably need all of the major sites (USCHO, CHN, etc) to come together to agree on it, and I'm not sure they'd be motivated enough to bother.
One alternative would be to ask collegehockeystats to do a dump file for us with the most relevant summary (game data) info. But I don't know under whose auspices they produce game information.
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Re: John t whelan ranking simulator
Originally posted by Patman View PostI still say the end goal is a simulator
Edit: I am not using a modular executable language... I don't know the differences in the -oriented but what I do is use a thing that primarily uses C as a platform. I suppose its possible to treat it as a script but not without installing software.
For me KRACH is deadly simple once you purée the data into a win matrix and game matrix. I've posted the code for that before.
I'll say the big thing is if we can adopt a data input standard that will go a long way.
A standard input format would be great, but you'd probably need all of the major sites (USCHO, CHN, etc) to come together to agree on it, and I'm not sure they'd be motivated enough to bother.
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Re: John t whelan ranking simulator
Originally posted by JimDahl View PostI agree, I interpreted OWP and OOWP as being straight (not with the home/away weightings). So, my OWP and OOWP calculations are essentially unchanged from previous years.
A point of disagreement in the past has been whether this process is recursive. I've always been pretty convinced that they calculate RPI once, then drop all the games that make it go up if you drop them. Others have wondered if you then need to make another pass to see if the new, higher RPI, has pushed any new games into "adverse" territory (repeating until you don't find any). That matters a lot more this time of year than later, so I'm not sure we've ever had a conclusive test come tournament time.
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Re: John t whelan ranking simulator
Originally posted by FlagDUDE08 View PostSorry for being unclear with the second point. I meant in terms of OWP and OOWP. The sources I have say not to take weighting into account, and to do a straight 1.0/0.0/0.5 for each game.
One thing I did notice with calculations, at least between RHamilton and myself, is that we had different games to remove for various teams. I wonder if this is the case for us.Last edited by JimDahl; 11-19-2013, 08:29 AM.
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Re: John t whelan ranking simulator
Originally posted by JimDahl View PostIf the only differences are in teams with dropped wins, this is probably the difference. Our analysis of how to calculate Minnesota a page or two back was otherwise identical.
I'm not sure what this means.
I'm assuming this is unchanged from the past -- OOWP is simply the average of the OWP's for each opponent (so does not include games against each opponent).
I'm again assuming unchanged from the past -- average of records.
One thing I did notice with calculations, at least between RHamilton and myself, is that we had different games to remove for various teams. I wonder if this is the case for us.
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Re: John t whelan ranking simulator
Originally posted by FlagDUDE08 View PostAs for Jim's and my differences, we've already discussed a disagreement in Quality Wins Bonus.
I will also ask Jim if he is taking weighting into account on RatingsPI
One other factor that could be making a difference is how OOWP is calculated, specifically whether games involving the team in question should be counted. Some sources say yes, others say no.
One other thing that could cause issue is specifically how OWP and OOWP is calculated. Do you take a cumulative record, or do you take the average of each team's records?
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Re: John t whelan ranking simulator
Originally posted by Numbers View PostFlag, Jim Dahl,
Just a note. Your RPI tables do not agree with each other, and neither agrees with what is posted on USCHO or CHN (those 2 have the same).
One other thing that could cause issue is specifically how OWP and OOWP is calculated. Do you take a cumulative record, or do you take the average of each team's records?
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Re: John t whelan ranking simulator
Flag, Jim Dahl,
Just a note. Your RPI tables do not agree with each other, and neither agrees with what is posted on USCHO or CHN (those 2 have the same).
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Originally posted by goblue78 View PostThis is all interesting, and thanks, Flagdude, for your service here, but I'm spiritually with patman. Sometime around New Years' I'll reprogram my previous lightning fast Stata/Mata code and do this for real. (It also does KRACH and home/road/tie adjusted KRACH.) But I like the Java App because at least it will tell me if I'm matching your results. As I've done before, I'm happy to make that code available to everyone similarly obsessed. And making the results available on a dynamic basis is a real service, FD. Thanks.
Edit: I am not using a modular executable language... I don't know the differences in the -oriented but what I do is use a thing that primarily uses C as a platform. I suppose its possible to treat it as a script but not without installing software.
For me KRACH is deadly simple once you purée the data into a win matrix and game matrix. I've posted the code for that before.
I'll say the big thing is if we can adopt a data input standard that will go a long way.Last edited by Patman; 11-18-2013, 10:51 PM.
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