Player Rating Calculator

[rscd20]

I'm trying to anticipate what my rating will be at the next update.

I have been looking around for a little while on what the PDGA formula is to calculate a player's rating based on the rounds they have played. I remember seeing it years ago but cannot find it again.
I know that each update your rating changes based the number of rounds used. I am trying to find out how rounds are selected to be used, and if some are weighted heavier than others.

Do they go back 365 days?
Drop the lowest round?
Double the highest round?
Anything else?

 

[Discette]

I'm trying to anticipate what my rating will be at the next update.

I have been looking around for a little while on what the PDGA formula is to calculate a player's rating based on the rounds they have played. I remember seeing it years ago but cannot find it again.
I know that each update your rating changes based the number of rounds used. I am trying to find out how rounds are selected to be used, and if some are weighted heavier than others.

Do they go back 365 days?
Drop the lowest round?
Double the highest round?
Anything else?

PDGA website can answer all those questions. http://www.pdga.com/faq

If that is not detailed enough, try this: http://www.pdga.com/files/PDGARatingsGuide_0.pdf

 

[rscd20]

PDGA website can answer all those questions. http://www.pdga.com/faq

If that is not detailed enough, try this: http://www.pdga.com/files/PDGARatingsGuide_0.pdf

Those talk about how ratings are calculated for each round, versus the other players at that event. I am looking for how to calculate your overall rating based on your event history.

 

[BuzzzChief]

Those talk about how ratings are calculated for each round, versus the other players at that event. I am looking for how to calculate your overall rating based on your event history.

The second paragraph in the Ratings Guide describes exactly what you're asking:

All properly reported PDGA events for the past 12 months are included in a player's ratings calculation. If you have less than 8 rounds of data, the program will go back as far as 24 months until it either finds 8 total rounds, or it will select all your rounds if less than 8. All members should receive a rating even if they only have one round of information in the database. Almost all of your rounds are counted, but those more than 2.5 standard deviations or more than 100 points below your average are dropped (about 1 in 50). Your most recent 25% (1/4) of your rounds will be double weighted in the calculation so your current performance is slightly more important. If you do not complete a round (indicated in event scores as DNF or 999), it is not included in your ratings round count.

 

[rscd20]

The second paragraph in the Ratings Guide describes exactly what you're asking:

OMG!!!! How did I miss this! Thank you so much!

 

[ChrisWoj]

The second paragraph in the Ratings Guide describes exactly what you're asking:

It forgets to state that all rounds are weighted by number of holes. So a round of 27 holes is going to count for 1.5 times as much as an 18 hole round.

The way to calc it is... lets say I played a tournament with 1 18 hole round and 2 27 hole rounds...

Rd 1 - 27 hole - 987
Rd 2 - 18 hole - 994
Rd 3 - 27 hole - 1002

987 x 27 = 26649
994 x 18 = 17892
1002 x 27 = 27054

26649 + 17892 + 27054 = 71595 total rating points
27 + 18 + 27 = 72 total holes played

71595 rating points over 72 holes = 994.375 rating for the event (very close to a straight average in this case because I put the two 27 hole rounds at approximately the same distance from the 18 hole round above and below).

 

[rscd20]

It forgets to state that all rounds are weighted by number of holes. So a round of 27 holes is going to count for 1.5 times as much as an 18 hole round.

The way to calc it is... lets say I played a tournament with 1 18 hole round and 2 27 hole rounds...

Rd 1 - 27 hole - 987
Rd 2 - 18 hole - 994
Rd 3 - 27 hole - 1002

987 x 27 = 26649
994 x 18 = 17892
1002 x 27 = 27054

26649 + 17892 + 27054 = 71595 total rating points
27 + 18 + 27 = 72 total holes played

71595 rating points over 72 holes = 994.375 rating for the event (very close to a straight average in this case because I put the two 27 hole rounds at approximately the same distance from the 18 hole round above and below).

Wow! That adds a whole other level to my excel sheet! Now I know why something was missing. I thought I was having an issue with the standard deviation. It appears that only 2.0 StdDevs was required to drop one of my scores like the PDGA site shows. But when I plug in 2.5 StdDevs it keeps in included. Maybe this will help....

I see how that can make a difference:
(987 + 994 + 1002) / 3 rounds = 995.333 rating
(26649 + 17892 + 27054) / 72 holes = 994.375 rating

That is a very important point. I wonder why they left it off!

 

[JC17393]

Wow! That adds a whole other level to my excel sheet! Now I know why something was missing. I thought I was having an issue with the standard deviation. It appears that only 2.0 StdDevs was required to drop one of my scores like the PDGA site shows. But when I plug in 2.5 StdDevs it keeps in included. Maybe this will help....

I see how that can make a difference:
(987 + 994 + 1002) / 3 rounds = 995.333 rating
(26649 + 17892 + 27054) / 72 holes = 994.375 rating

That is a very important point. I wonder why they left it off!

I think there are some proprietary elements to the formula/system. Not saying that's one of them, but that is the reason that the whole thing isn't laid out step by step somewhere enabling anyone to duplicate it.

 

[jeverett]

I think there are some proprietary elements to the formula/system. Not saying that's one of them, but that is the reason that the whole thing isn't laid out step by step somewhere enabling anyone to duplicate it.

I think the "proprietary elements" are more in how round ratings themselves are calculated, rather than player ratings. For example, we know that the PDGA uses *some* method of linear regression to calculate the SSA, but they've never published precisely how they calculate it.

 

[cjman]

It forgets to state that all rounds are weighted by number of holes. So a round of 27 holes is going to count for 1.5 times as much as an 18 hole round.

The way to calc it is... lets say I played a tournament with 1 18 hole round and 2 27 hole rounds...

Rd 1 - 27 hole - 987
Rd 2 - 18 hole - 994
Rd 3 - 27 hole - 1002

987 x 27 = 26649
994 x 18 = 17892
1002 x 27 = 27054

26649 + 17892 + 27054 = 71595 total rating points
27 + 18 + 27 = 72 total holes played

71595 rating points over 72 holes = 994.375 rating for the event (very close to a straight average in this case because I put the two 27 hole rounds at approximately the same distance from the 18 hole round above and below).

I have never heard of this before...has chuck ever talked about this?

 

[Lewis]

I have never heard of this before...has chuck ever talked about this?

Me either, but Chuck is likely to see this thread soon and reply.

 

[krupicka]

Much of the details are out there if you know where to look, but yes the exact details of some portions are intentionally no longer publicized/commented on.