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  #11  
Old 11-19-2013, 09:08 AM
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Or just add 1500 to everyone's rating so those currently above 699 could all feel good as Masters or higher before reaching age 40.
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  #12  
Old 11-19-2013, 09:16 AM
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Nemmers Nemmers is offline
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Quote:
Originally Posted by mashnut View Post
In disc golf, the 10 rating points roughly corresponds to 1 stroke...
Ahhh.....I didn't know that. That's useful info.

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Originally Posted by mashnut View Post
I really don't think it's useful or practical to break things down to hundredths of strokes.
I agree.

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Originally Posted by mashnut View Post
Also, the most recent rounds in your PDGA rating are double weighted to help mitigate the effect of old rounds dragging down the rating of a rapidly improving player.
Thanks for schooling me....didn't know that either. Guess I need to do more homework.
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  #13  
Old 11-19-2013, 10:51 AM
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Lewis Lewis is offline
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You could also divide everyone's rating by 10, so that 1 "point" is equivalent to 1 stroke. This would make the spread appear larger because each "point" is greater relative to the whole rating value.
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  #14  
Old 11-19-2013, 11:48 AM
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Nemmers, you are thinking outside the box, and that's refreshing.
Your point about the ratings being tightly gouped is a legitimate question.
Given the nature of the game/sport, and the nature of the scoring system, and the fact that everyone plays different courses in different weather against different opponents, the PDGA scoring system is probably as good as it needs to be.
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Old 11-19-2013, 12:13 PM
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You could implement a version of elo for your local dg league if you wanted to, and you can even do it for the "multiplayer" environment of disc golf. However, something the PDGA system does that elo doesn't is estimate the expected margin of victory, which is useful for handicapping. Elo, for its part, only assesses the likelihood of winning. Trying to assess margin of victory would be crazy hard, if not impossible, in chess, of course.

Last edited by Lewis; 11-19-2013 at 12:16 PM.
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  #16  
Old 11-19-2013, 12:30 PM
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Nemmers Nemmers is offline
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Originally Posted by Dan Ensor View Post
Tournaments drop off after a year if you have enough rounds more recently. It's less likely to find a chess player that you're suited to than a dg course, so if ratings swung madly someone could jump out of the division they should be in just in time to play a course that's not suited to them.
Aha.....then it makes sense to calculate ratings the way they do then.

There's a perk in that as well: People don't get to earn a high rating one year and then quit so they don't risk losing their "rating prestige."
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  #17  
Old 11-19-2013, 12:49 PM
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Originally Posted by Nemmers View Post
Aha.....then it makes sense to calculate ratings the way they do then.

There's a perk in that as well: People don't get to earn a high rating one year and then quit so they don't risk losing their "rating prestige."
Hi Nemmers,

It looks like a lot of folks have already mentioned some of the issues with comparing Elo (and similar rating systems) to the PDGA system, but just as another item to consider, Elo (and TrueSkill, among others) are built around win/loss percentage ratios. i.e. if you have a 1950 chess player and a 2050 player, the Elo system will predict a win/loss percentage for these two players, something that a disc golf rating system doesn't do (for one reason, because it deals with relative scores, rather than strict win/loss ratios).

The PDGA system, by comparison, describes only the (weighted) 'average' performance of the player. It doesn't, for example, include any percentage breakdown (or standard deviation) of how a player is predicted to throw.

The other major element to Elo (and similar ratings systems) is that they use two values to represent each player: the established 'rating', but also a measurement of just how accurate that rating is. By contrast, the PDGA system does not utilize a second per-player value at all: once a player becomes a 'propagator' (they have at least 8 rated rounds in a two-year span), every round they produce is considered 'equally meaningful' to the overall ratings (and equally meaningful to all other propagators' rounds). Edit: this is slightly incorrect: if a propagator initially throws a round that will be rated >60 points below their rating, they will be excluded as a propagator for that round. It still, however, is not a direct assessment of how 'meaningful' their rating and round data is.

Anyway, I'd love to talk more about ratings systems, so if you have any other questions/concerns, fire away.

Second edit: I should probably add that I formerly played Chess, as well, although even at my best when I was playing with a community college club I was rated ~1500. :P
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  #18  
Old 11-19-2013, 09:19 PM
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Originally Posted by scarpfish View Post
For most players who never see the upper 900's, player ratings most certainly do go up and down in mad swings.

You also have to consider that you are comparing a strategy game where people generally get better with experience and can continue to improve throughout their lives, to a physical activity where a player's abilities tend to wane with age. Even the guy with 12 World Championships and his signature on thousands of discs isn't what he once was.

While I agree with your point as a whole, the Ken Climo example is null.

His rating decrease says more about the competitors he's facing than it does about his skill level. I'm willing to bet that Kenny's skill has dropped off very little (if at all) in the last 10 years.
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  #19  
Old 11-19-2013, 10:28 PM
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Nemmers Nemmers is offline
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Originally Posted by jeverett View Post
Hi Nemmers,

It looks like a lot of folks have already mentioned some of the issues with comparing Elo (and similar rating systems) to the PDGA system, but just as another item to consider, Elo (and TrueSkill, among others) are built around win/loss percentage ratios. i.e. if you have a 1950 chess player and a 2050 player, the Elo system will predict a win/loss percentage for these two players, something that a disc golf rating system doesn't do (for one reason, because it deals with relative scores, rather than strict win/loss ratios).

The PDGA system, by comparison, describes only the (weighted) 'average' performance of the player. It doesn't, for example, include any percentage breakdown (or standard deviation) of how a player is predicted to throw.

The other major element to Elo (and similar ratings systems) is that they use two values to represent each player: the established 'rating', but also a measurement of just how accurate that rating is. By contrast, the PDGA system does not utilize a second per-player value at all: once a player becomes a 'propagator' (they have at least 8 rated rounds in a two-year span), every round they produce is considered 'equally meaningful' to the overall ratings (and equally meaningful to all other propagators' rounds). Edit: this is slightly incorrect: if a propagator initially throws a round that will be rated >60 points below their rating, they will be excluded as a propagator for that round. It still, however, is not a direct assessment of how 'meaningful' their rating and round data is.

Anyway, I'd love to talk more about ratings systems, so if you have any other questions/concerns, fire away.

Second edit: I should probably add that I formerly played Chess, as well, although even at my best when I was playing with a community college club I was rated ~1500. :P
Good stuff...most of which I hadn't considered. Being more of a "big-picture" thinker I get lost in the weeds when it comes to details. Which is to say I have a tendency to spout off at the mouth and start talking all manner of she-it before I've considered all the possibilities and ramifications.

Thanks to all y'all for the education!
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  #20  
Old 11-20-2013, 04:22 AM
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Dan Ensor Dan Ensor is offline
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Quote:
Originally Posted by Allurex View Post
While I agree with your point as a whole, the Ken Climo example is null.

His rating decrease says more about the competitors he's facing than it does about his skill level. I'm willing to bet that Kenny's skill has dropped off very little (if at all) in the last 10 years.
My understanding is that ratings are supposed to be based on the original propagators. I remember seeing a quote like "There's no limit to the number of 1000 rated players". In other words, ratings should not at all be based on the competitors you're playing against. A 1000 rated round is a 1000 rated round.

I don't see how they would correct for improvement over the off-season, though, so I don't think that's accurate. Just how it's supposed to work.
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