Not a fan of GHIN new 9 hole scoring system

[Pnwpingi210]

29 minutes ago, gavinski91 said:

Saw a post on Reddit the other day where someone's buddy splits his 18-hole rounds into two 9-hole rounds whenever he plays below his handicap in an attempt to keep his handicap up.

 

Obvious handicap manipulation aside, for mid-handicappers that could be remarkably effective. I played a round at +2 at my local 9-hole course recently. If I had played a full 18 at +4, it would post as a 6.8 differential, but because it was only 9 holes and I'm ~12 HI it posted as an 11.4 differential.

For most, playing + 4 for a full 18 is much harder/more rare than a  +2 over 9.    
 

The more holes you play, the closer you should play to you index.

Edited July 30, 2024 by Pnwpingi210

[Ron1221]

My main issue with it is that I just consistently play worse on seemingly every back 9.  So even if they're rated harder, I play worse than even the increased rating.

At the same time, I think my handicap is probably only 0.5 lower than it would be without those 9's, so I don't think it is really moving things.

[gavinski91]

11 minutes ago, Pnwpingi210 said:

For most, playing + 4 for a full 18 is much harder/more rare than a  +2 over 9.    
 

The more holes you play, the closer you should play to you index.

Statistically having the "missing 9" regress to the mean definitely makes the most sense. I play a lot more 9-hole rounds than 18 (only 31% of my rounds were full 18s going back to the start of 2023), but of my 18 hole rounds I only scored better on the front 9 on 30% of them.

So the new system probably has the effect of raising my handicap, but I will concede that on average across the entire population it's probably the most accurate solution.

[Pnwpingi210]

3 minutes ago, gavinski91 said:

Statistically having the "missing 9" regress to the mean definitely makes the most sense. I play a lot more 9-hole rounds than 18 (only 31% of my rounds were full 18s going back to the start of 2023), but of my 18 hole rounds I only scored better on the front 9 on 30% of them.

So the new system probably has the effect of raising my handicap, but I will concede that on average across the entire population it's probably the most accurate solution.

How many of the 18 hole rounds are/were used in your 8 best?

 

one would think 2-3.

 

the more I read and learn about this it just makes sense for a golfer to have an 18 and 9 hole index.  

Edited July 30, 2024 by Pnwpingi210

[DaveLeeNC]

20 minutes ago, Pnwpingi210 said:

For most, playing + 4 for a full 18 is much harder/more rare than a  +2 over 9.    
 

The more holes you play, the closer you should play to you index.

For accuracy's sake, as you play more holes the closer you should play to (typically) 3 strokes higher than your index. That is why the formula for converting a 9 hole differential to an 18 hole differential has "an adder".

 

dave

Edited July 30, 2024 by DaveLeeNC

[Pnwpingi210]

Just now, DaveLeeNC said:

For accuracy's sake, as you play more holes the closer you should play to (typically) 3 strokes higher than your index. That is why the formula for converting a 9 hole differential to an 18 hole differential has "an adder".

 

dave

Yes that is a more accurate and specific way of saying it.

[gavinski91]

9 minutes ago, Pnwpingi210 said:

How many of the 18 hole rounds are/were used in your 8 best?

 

one would think 2-3.

 

the more I read and learn about this it just makes sense for a golfer to have an 18 and 9 hole index.  

Of my revision scores, 2 are 9-hole scores, 2 are combined-9-for-18-hole scores from 2023, and 4 are true 18-hole scores.

[betarhoalphadelta]

21 minutes ago, Pnwpingi210 said:

 

the more I read and learn about this it just makes sense for a golfer to have an 18 and 9 hole index.  

 

I know you've said this several times in this thread, but the problem with that is that you could have the two indexes be RADICALLY divergent if a player is playing, say, 90%+ of their rounds that are one or the other. 

 

As an example, let's say someone is a busy professional with kids. They basically can barely play on the weekends, but they can get out for an early 9 before work or a late 9 after work often, and on the weekends probably only get some range / putting green time b/c of kids. 

 

So let's say they only play 4-5 rounds of 18 holes per year, but 50+ rounds of 9 hoes per year. And they're working HARD on improving their game. So 3 years ago they were a 15 index (7.5 for 9 holes) and they've been grinding and grinding to the point where they're a 1 index for 9 holes. Well, they're going to have enough old 18-hole scores in their last 20 (that go back 4+ years) that they're NOT going to be carrying a 2 index for 18 holes. If they step onto an 18-hole tee box in competition and smoke someone, that person is going to call them a sandbagger. 

 

And for many of us, it's the opposite. The only time we get on the course (due to job & other responsibilities) is weekends, so if we're actually going to play we're going to play 18. Maybe you have only played five 9-hole rounds in the last 3 years. If your 18-hole handicap has moved significantly in the last 3 years, how reasonable is it for that 9-hole handicap that is radically out of date to be used in a 9-hole competition? 

 

Having both just doesn't make sense. There are going to be too many players that have wildly divergent 9- and 18-hole indexes that it's no longer useful for what we want handicapping to be useful for (facilitating games between players of differing skill levels). 

 

That said, I'd still rather stick with the combining scores method than the new method. But clearly that's just me. The USGA disagrees.

[Pnwpingi210]

10 minutes ago, betarhoalphadelta said:

 

I know you've said this several times in this thread, but the problem with that is that you could have the two indexes be RADICALLY divergent if a player is playing, say, 90%+ of their rounds that are one or the other. 

 

As an example, let's say someone is a busy professional with kids. They basically can barely play on the weekends, but they can get out for an early 9 before work or a late 9 after work often, and on the weekends probably only get some range / putting green time b/c of kids. 

 

So let's say they only play 4-5 rounds of 18 holes per year, but 50+ rounds of 9 hoes per year. And they're working HARD on improving their game. So 3 years ago they were a 15 index (7.5 for 9 holes) and they've been grinding and grinding to the point where they're a 1 index for 9 holes. Well, they're going to have enough old 18-hole scores in their last 20 (that go back 4+ years) that they're NOT going to be carrying a 2 index for 18 holes. If they step onto an 18-hole tee box in competition and smoke someone, that person is going to call them a sandbagger. 

 

And for many of us, it's the opposite. The only time we get on the course (due to job & other responsibilities) is weekends, so if we're actually going to play we're going to play 18. Maybe you have only played five 9-hole rounds in the last 3 years. If your 18-hole handicap has moved significantly in the last 3 years, how reasonable is it for that 9-hole handicap that is radically out of date to be used in a 9-hole competition? 

 

Having both just doesn't make sense. There are going to be too many players that have wildly divergent 9- and 18-hole indexes that it's no longer useful for what we want handicapping to be useful for (facilitating games between players of differing skill levels). 

 

That said, I'd still rather stick with the combining scores method than the new method. But clearly that's just me. The USGA disagrees.

That is the challenge.  
 

You would definitely need something to account for those two scenarios. 

 

 Just trying to think of a way the 9 hole folks can track their progress for 9 hole rounds without having 9 holes they didn’t play with an adder as part of their score.

 

Im all good with the current system.  Its not perfect, but likely more accurate based on the xxxxxxxxxxx of rounds that the USGA evaluated.

Edited July 30, 2024 by Pnwpingi210

[betarhoalphadelta]

2 minutes ago, Pnwpingi210 said:

 

Just trying to think of a way the 9 hole folks can track their progress for 9 hole rounds without having 9 holes they didn’t play with an adder as part of their score.

 

 

You combine the consecutive 9-hole rounds into a composite 18-hole score. That way it's based on holes played. 

 

Is that system perfect? No. You could have situations where one 9-hole round is played in the warm sun in perfect conditions and the next one is 45-degrees, rainy, and windy, and the two are combined. (Although you'd think PCC should account for the latter.) But I think for the players who play 90%+ of their rounds as 9-holes, they're playing often enough that I doubt it makes much statistical difference to their index. 

[Pnwpingi210]

1 minute ago, betarhoalphadelta said:

 

You combine the consecutive 9-hole rounds into a composite 18-hole score. That way it's based on holes played. 

 

Is that system perfect? No. You could have situations where one 9-hole round is played in the warm sun in perfect conditions and the next one is 45-degrees, rainy, and windy, and the two are combined. (Although you'd think PCC should account for the latter.) But I think for the players who play 90%+ of their rounds as 9-holes, they're playing often enough that I doubt it makes much statistical difference to their index. 

I think the USGA pointed out the flaws in that system.. there’s an infographic out there speaking to it.

[betarhoalphadelta]

4 minutes ago, Pnwpingi210 said:

I think the USGA pointed out the flaws in that system.. there’s an infographic out there speaking to it.

 

Yes, they said the following about the benefits:

 

• This change benefits the many players who regularly play and post 9-hole rounds because it is more responsive. Players will no longer have to wait for another 9-hole score to be posted for an 18-hole Score Differential to be calculated.

If you regularly play and post 9-hole scores, why is this wait such a problem? The issue SHOULD have been for those players who irregularly play and post 9-hole scores, because they might have weeks-months between 9-hole rounds. Those who play and post 9-hole rounds regularly will have their scores in the old system updated pretty frequently, because they're playing/posting regularly. 

 

• This change provides a better indicator of how a player will normally perform over 18 holes on a given day when compared to combining 9-hole scores from different days and under different playing conditions.

 

Assertion w/o data. Maybe the data exists. Can't evaluate without it. Again, one would think that the PCC should account for playing conditions if it's doing its job. And I'd think if you "regularly" play/post 9 hole scores, this would end up being statistically irrelevant. 

 

• This new method produces a more consistent and comparable Handicap Index for those who post 9-hole scores.
• Prior to 2024, the order in which the 9-hole scores were combined could add volatility to the Handicap Index.
• It was also common for two good 9-hole scores to combine and produce an 18-hole Score Differential which was lower than any of the Score Differentials based on an 18-hole score in the player’s scoring record - which resulted in a Handicap Index that may be difficult for the player to play to.

 

Again, assertion w/o data. Agreed that the order in which the 9-hole scores were combined could add volatility. But for players who regularly play/post 9 hole rounds, does it happen at a statistically significant level? I'd argue that for players that irregularly play/post 9 hole rounds, it doesn't matter. And yes, it's possible that two good 9-hole scores could combine and produce an 18-hole score that was the lowest in their scoring record. However, they say "common" and don't quantify what "common" means--was it more common than "expected", meaning more often than 5% of the time? One of your scores must be the lowest, so unless the combined 9-hole scores were the lowest in your scoring record MORE than 5% of the time, it may or may not justify the change. 

 

 

[Pnwpingi210]

1 minute ago, betarhoalphadelta said:

 

Yes, they said the following about the benefits:

 

• This change benefits the many players who regularly play and post 9-hole rounds because it is more responsive. Players will no longer have to wait for another 9-hole score to be posted for an 18-hole Score Differential to be calculated.

If you regularly play and post 9-hole scores, why is this wait such a problem? The issue SHOULD have been for those players who irregularly play and post 9-hole scores, because they might have weeks-months between 9-hole rounds. Those who play and post 9-hole rounds regularly will have their scores in the old system updated pretty frequently, because they're playing/posting regularly. 

 

• This change provides a better indicator of how a player will normally perform over 18 holes on a given day when compared to combining 9-hole scores from different days and under different playing conditions.

 

Assertion w/o data. Maybe the data exists. Can't evaluate without it. Again, one would think that the PCC should account for playing conditions if it's doing its job. And I'd think if you "regularly" play/post 9 hole scores, this would end up being statistically irrelevant. 

 

• This new method produces a more consistent and comparable Handicap Index for those who post 9-hole scores.
• Prior to 2024, the order in which the 9-hole scores were combined could add volatility to the Handicap Index.
• It was also common for two good 9-hole scores to combine and produce an 18-hole Score Differential which was lower than any of the Score Differentials based on an 18-hole score in the player’s scoring record - which resulted in a Handicap Index that may be difficult for the player to play to.

 

Again, assertion w/o data. Agreed that the order in which the 9-hole scores were combined could add volatility. But for players who regularly play/post 9 hole rounds, does it happen at a statistically significant level? I'd argue that for players that irregularly play/post 9 hole rounds, it doesn't matter. And yes, it's possible that two good 9-hole scores could combine and produce an 18-hole score that was the lowest in their scoring record. However, they say "common" and don't quantify what "common" means--was it more common than "expected", meaning more often than 5% of the time? One of your scores must be the lowest, so unless the combined 9-hole scores were the lowest in your scoring record MORE than 5% of the time, it may or may not justify the change. 

 

 

Fair enough.  
 

Im not going to debate what the USGA did in their analysis.  I don’t think it’s a reasonable expectation for every governing body, company, or entity to show their work or provide full data sets to the general public when they claimed to perform an analysis.

 

 You can choose to believe or not believe their assertions after analyzing the data they have access to based on your anecdotal experiences and personal opinions or not.  

[iacas]

3 hours ago, gavinski91 said:

Saw a post on Reddit the other day where someone's buddy splits his 18-hole rounds into two 9-hole rounds whenever he plays below his handicap in an attempt to keep his handicap up.

 

I hope someone reported him.

 

1 hour ago, betarhoalphadelta said:

• This change provides a better indicator of how a player will normally perform over 18 holes on a given day when compared to combining 9-hole scores from different days and under different playing conditions.

Assertion w/o data. Maybe the data exists. Can't evaluate without it. Again, one would think that the PCC should account for playing conditions if it's doing its job. And I'd think if you "regularly" play/post 9 hole scores, this would end up being statistically irrelevant.

 

They have over 300 million rounds posted from 2020 through 2023 (since the WHS), so suffice to say they have the data.

 

Just because they didn't share it all with you (or the Internet at large)… doesn't mean they don't have it. Of course the data exists. And they tested the final formula and other variations against it all.

[Imp]

5 hours ago, Pnwpingi210 said:

For most, playing + 4 for a full 18 is much harder/more rare than a  +2 over 9.    
 

The more holes you play, the closer you should play to you index.

I'm generally the opposite. Show up, coming in hot because wife needed xyz done, to a course I haven't played, little time to practice/warm up before going off (and rarely are the practice greens the same as the actual). So, I go out and do something like 44-48 on the front, and then in the 30s on the back as I figure things out. Like last weekend, I went 46/36. I have that knack. I'm almost always lower on the back 9 than the front.  

[Pnwpingi210]

8 minutes ago, Imp said:

I'm generally the opposite. Show up, coming in hot because wife needed xyz done, to a course I haven't played, little time to practice/warm up before going off (and rarely are the practice greens the same as the actual). So, I go out and do something like 44-48 on the front, and then in the 30s on the back as I figure things out. Like last weekend, I went 46/36. I have that knack. I'm almost always lower on the back 9 than the front.  

Yup.  The more holes you play closer to 18,  the closer you will shoot 3 strokes higher than you index. Works both ways.

[DaveLeeNC]

3 hours ago, iacas said:

Just because they didn't share it all with you (or the Internet at large)… doesn't mean they don't have it. Of course the data exists. And they tested the final formula and other variations against it all.

 

Is there a reference or something to a statement from the USGA (or R&A) that they chose the current algorithm for 9 hole rounds with the goal of creating the most accurate handicap possible? The only statements that I have seen is that they did a bunch of analysis to find the 'most likely 18 hole differential given a 9 hole differential and a players current index". These are NOT the same thing (for golfers who play a lot of 9 hole rounds). 

 

But maybe that statement is out there and I missed it. 

 

dave

[davep043]

10 hours ago, DaveLeeNC said:

 

Is there a reference or something to a statement from the USGA (or R&A) that they chose the current algorithm for 9 hole rounds with the goal of creating the most accurate handicap possible? The only statements that I have seen is that they did a bunch of analysis to find the 'most likely 18 hole differential given a 9 hole differential and a players current index". These are NOT the same thing (for golfers who play a lot of 9 hole rounds). 

 

But maybe that statement is out there and I missed it. 

 

dave

There's this:

https://www.usga.org/content/usga/home-page/handicapping/world-handicap-system/2024-revision/2024-treatment-of-9-hole-scores-FAQ.html

Which seems a bit of a PR release rather than a really detailed explanation.  

[nsxguy]

14 hours ago, DaveLeeNC said:

 

Is there a reference or something to a statement from the USGA (or R&A) that they chose the current algorithm for 9 hole rounds with the goal of creating the most accurate handicap possible? The only statements that I have seen is that they did a bunch of analysis to find the 'most likely 18 hole differential given a 9 hole differential and a players current index". These are NOT the same thing (for golfers who play a lot of 9 hole rounds). 

 

But maybe that statement is out there and I missed it. 

 

dave

 

Long ago my 3rd grade teacher told me not to answer a question with a question.

 

So, with apologies to Ms. Leonard, can you think of a reason why the WHS would choose an algorithm that wouldn't reflect the "most accurate handicap possible" ? 

 

And while you're at it, why wouldn't the "most likely 18-hole differential" not be the "most accurate" ?

 

TIA

[DaveLeeNC]

8 hours ago, nsxguy said:

 

Long ago my 3rd grade teacher told me not to answer a question with a question.

 

So, with apologies to Ms. Leonard, can you think of a reason why the WHS would choose an algorithm that wouldn't reflect the "most accurate handicap possible" ? 

 

And while you're at it, why wouldn't the "most likely 18-hole differential" not be the "most accurate" ?

 

TIA

 

@nsxguy , since you answered a question with two questions then you are fine regarding the rules of your 3rd grade teacher 🙂

 

Regarding the question And while you're at it, why wouldn't the "most likely 18-hole differential" not be the "most accurate" ? , if you had 20 consecutive scores where the differential of each score was 'the most likely 18 hole differential given your current index", your index would go up (about 3 strokes - ballpark). The handicap index algorithm uses your best scores, not your most likely scores (which are higher than your best scores). Similarly when you have a bunch of 9 holes scores that create 18 hole differentials by supplementing your actual 9 hole diff's with 'most likely' 9 hole diffs, your index will tend to go up. Maybe not if you are one of those golfers who always fold on the back side, but for the general case. FWIW, I tend to shoot better on the back side (I putt better and sometimes 'figure it out on full swing stuff'), but that is me. 

 

So given the above the only way to fix this is to use something that is better than your most likely 9 hole differential. I can see why an organization like the USGA might be reluctant to do that in such an obvious and explicit manner. And doing this will create some other interesting anomalies.  But as it stands, across a large golfing population which is a mix of only 18 hole golfers in one group and only 9 hole golfers in the other, the 9 hole golfers will tend to have higher indexes. I suspect that we will all survive that 😃

 

dave

 

ps. The RB's could create a much more complicated system that analyzes all your 18 and 9 hole scores and come up with a 'opaque/mysterious as the PCC algorithm' that would probably be an improvement but not be very popular with the masses, IMHO. 

Edited August 1, 2024 by DaveLeeNC