Why are course ratings and slope not based on score data?

[Newby]

34 minutes ago, davep043 said:

.  I can see what you're saying, to change a "stroke and distance area" into a "red penalty area" would seem to me to decrease the penalty associated with it. 

My copy of the rating manual (going back a couple of years since I retired from rating) indicates virtually no difference to "extreme rough/OB" and "PA" factors. However, it does take account of the likelihood of a slope kicking the ball towards the problem.

[ThinkingPlus]

2 hours ago, iacas said:

 

They're not that hard to find. Or, volunteer with your AGA and truly get into it.

 

 

Bah, DECADE is just a paint-by-numbers version of my Shades of Grey from the year before. 😉 

 

 

That's fine. If the "stuff" is literally the same, moving the PA to include it is often easier because it gives options: you can still play from the PA, or take relief (closer to the green) where it last crossed (assuming the PA is red, which it almost certainly is beside the green).

 

What I'm saying is that even though the person said it made the hole harder, once they actually calculate it, he may have misspoken. If it was OB/Extreme rough, it would have made the hole easier as you say.

Well, I've been in a decent number of convos on here and no one has volunteered a PDF. Casual searches come up zero, too.

 

Not a DECADE fan, huh. I've never subscribed so I don't know the secret handshake, but the concepts that I have heard described seem valid. I probably am a little conservative off the tee vs. DECADE and more aggressive at chasing pins which is frowned upon. Shooting even par on many of the courses I play these days is almost a waste of time. I pretty much am shooting for 4 - 6 birdies or better per round. Anything less is sort of meh. My 1st world burden, LOL!

[iacas]

4 hours ago, ThinkingPlus said:

Not a DECADE fan, huh.

 

I didn't say that. 😉

[Halebopp]

20 hours ago, ThinkingPlus said:

Well, I've been in a decent number of convos on here and no one has volunteered a PDF. Casual searches come up zero, too.

 

Not a DECADE fan, huh. I've never subscribed so I don't know the secret handshake, but the concepts that I have heard described seem valid. I probably am a little conservative off the tee vs. DECADE and more aggressive at chasing pins which is frowned upon. Shooting even par on many of the courses I play these days is almost a waste of time. I pretty much am shooting for 4 - 6 birdies or better per round. Anything less is sort of meh. My 1st world burden, LOL!

 

I sent you a PDF copy of an old manual.

[Nels55]

I spoke to the course owner the other day and it seems that NCGA course rating team botched the job completely.  The course was previously rated at 6002 yards from the blues and several tees have been moved back since the previous rating.  The rating came back with a distance of 5800 yards.  LOL they said that the 526 yard par 5 16th hole was 380 yards long.  LOL I guess that they had a bad day...

[JohnB92]

My biggest issue with the rating system is how it mixes together course difficulty (how much space you have to land the shot, and penalty for missing) with course length. The way a good course rating system would work, you'd have to analyze what is the intended tee shot landing spot for each box, such that everyone is hitting the same general type of club into the green. Essentially the way a good set of Par 3s are done on a course. Everyone hitting the same general range of club for a long, medium or short style Par 3 (wood-4iron, 5-8 iron, 9i-SW). 

Then the question becomes, how big is the landing area for these intended clubs and how severe is the penalty for missing them? If you're not hitting those clubs, then you're playing the wrong tees. It's not that the course is harder from farther back its that it's by definition a different course than the designer intended. Until people understand how tee box selection works, it's going to be very hard to get true measurements of how hard a course actually is.

Maybe as shot tracking systems like Arccos become more widespread we can actually start gathering this data. The first place to fix this isn't on the entire course rating, it's to get the handicaps of the different holes correct. Sorry guys, but there's almost no way that a 490-yard Par 5 (from the back tee) should ever be the #1 or #2 handicap hole on that side. It would need OB on both sides all the way with an island green and massive bunkers everywhere else.

[StudentGolfer4]

6 minutes ago, JohnB92 said:

My biggest issue with the rating system is how it mixes together course difficulty (how much space you have to land the shot, and penalty for missing) with course length. The way a good course rating system would work, you'd have to analyze what is the intended tee shot landing spot for each box, such that everyone is hitting the same general type of club into the green. Essentially the way a good set of Par 3s are done on a course. Everyone hitting the same general range of club for a long, medium or short style Par 3 (wood-4iron, 5-8 iron, 9i-SW). 

Then the question becomes, how big is the landing area for these intended clubs and how severe is the penalty for missing them? If you're not hitting those clubs, then you're playing the wrong tees. It's not that the course is harder from farther back its that it's by definition a different course than the designer intended. Until people understand how tee box selection works, it's going to be very hard to get true measurements of how hard a course actually is.

Maybe as shot tracking systems like Arccos become more widespread we can actually start gathering this data. The first place to fix this isn't on the entire course rating, it's to get the handicaps of the different holes correct. Sorry guys, but there's almost no way that a 490-yard Par 5 (from the back tee) should ever be the #1 or #2 handicap hole on that side. It would need OB on both sides all the way with an island green and massive bunkers everywhere else.

I haven’t seen a current architect come out and say the goal is to have people hit similar clubs or anything like that. Given differences in individual peoples golf games I would actually think it’s almost impossible to do. The data is out there if the ruling bodies wanted to use it, but I don’t think they do, nor necessarily should. 
 

2022 driver data via Arcoss for handicaps 5-9.9. 
20-29 251

40-49 238

60-69 217

 

All these guys would have similar index’s so could easily (maybe should) play the same tee box but they will hit widely different clubs into greens. One of these guys is hitting driver 7-8 iron into the 400 yard hole and the other hits driver 3 wood hoping there isn’t any sort of forced carry required. The 140 yard “short” par 3 is a wedge for one of them and a mid iron for the other. 
 

I think the solution is to change the distance of the scratch male player from 250 to 275 yards. This would limit the affect distance has on the course rating. 

 

[ThinkingPlus]

17 minutes ago, StudentGolfer4 said:

I haven’t seen a current architect come out and say the goal is to have people hit similar clubs or anything like that. Given differences in individual peoples golf games I would actually think it’s almost impossible to do. The data is out there if the ruling bodies wanted to use it, but I don’t think they do, nor necessarily should. 
 

2022 driver data via Arcoss for handicaps 5-9.9. 
20-29 251

40-49 238

60-69 217

 

All these guys would have similar index’s so could easily (maybe should) play the same tee box but they will hit widely different clubs into greens. One of these guys is hitting driver 7-8 iron into the 400 yard hole and the other hits driver 3 wood hoping there isn’t any sort of forced carry required. The 140 yard “short” par 3 is a wedge for one of them and a mid iron for the other. 
 

I think the solution is to change the distance of the scratch male player from 250 to 275 yards. This would limit the affect distance has on the course rating. 

 

Increasing the performance of scratch golfers will just lower the CRs across the board for most courses. It would increase the slope across the board for most courses unless a corresponding increase in bogey golfer distance was made. Not sure any of that makes ratings and slopes more accurate.

[JohnB92]

25 minutes ago, StudentGolfer4 said:

I haven’t seen a current architect come out and say the goal is to have people hit similar clubs or anything like that. Given differences in individual peoples golf games I would actually think it’s almost impossible to do. The data is out there if the ruling bodies wanted to use it, but I don’t think they do, nor necessarily should. 
 

2022 driver data via Arcoss for handicaps 5-9.9. 
20-29 251

40-49 238

60-69 217

 

All these guys would have similar index’s so could easily (maybe should) play the same tee box but they will hit widely different clubs into greens. One of these guys is hitting driver 7-8 iron into the 400 yard hole and the other hits driver 3 wood hoping there isn’t any sort of forced carry required. The 140 yard “short” par 3 is a wedge for one of them and a mid iron for the other. 
 

I think the solution is to change the distance of the scratch male player from 250 to 275 yards. This would limit the affect distance has on the course rating. 

 

Yep, I agree with that on the scratch player issue. Although I'd argue those guys probably shouldn't be playing the same tee box. Maybe the 238 and 251 guys could. But 217/251 = 86% that's a pretty large difference, probably 3 or 4 clubs in total on the same hole. Just like your example. That guy should be playing from tees farther up. 

At the end of the day this really only matters for people who are playing at a handicap level of below 10, probably below 5. If you're a 15 - 20 HDCP the issue you're fighting is mostly clean ball contact, with any club, at any distance. I'd be willing to bet that you're going to have at least 5 penalty shots (according to Titleist the average golfer loses 5 or 6 balls per round), you'll probably duff, skull or shank 3 - 4 shots. Most likely not more than 3 up/downs (regardless of how many shots it took you to get up by the green) and probably a couple 3 putts. None of those things are influenced by the distance of the hole.

It only really matters when you start talking about situations like I had as a junior. I was a 1.5 - 2.5 HDCP and my dad was a 4 or 5. But his average drive was only 235, he was 50 years old and had two artificial hips. Whereas I was averaging 285, and we both would hit around 10-12 fairways/round (bad stat, but it was 2009 and that's what we tracked). While the Course Rating differences often said that I should be giving him 2 shots. We knew that we should actually be playing head-up, but I'd play 7000 and him from 58-6000 yards. It's those types of situations, where you have players who aren't losing shots due to bad swings (by comparison) but losing shots based on up/down conversions, making 12-foot putts and proper club selection when in-between clubs on approach shots. But that's only going to apply to the top % of golfers. For the guy who shoots 90+ it won't matter what tees he plays from, as long as it's somewhat reasonable. Almost all his bad shots would be bad shots with any club.

4 minutes ago, ThinkingPlus said:

Increasing the performance of scratch golfers will just lower the CRs across the board for most courses. It would increase the slope across the board for most courses unless a corresponding increase in bogey golfer distance was made. Not sure any of that makes ratings and slopes more accurate.

Probably no reason to increase the distance for a bogey golfer anyways. I think the data is pretty clear that the only people who have been substantially benefitting from the increase in club technology (distance wise) are the players who have the ball striking ability to capture that increase. Which is only going to be on the higher end of the skill spectrum.

Edited January 7 by JohnB92
Combined into a single post

[JohnB92]

Delete

Edited January 7 by JohnB92
Consolidated

[DaveLeeNC]

@JohnB92 You are ignoring a huge group of golfers - the old guys who have played all their lives and can't hit a driver 150 yards on the fly. I don't know what the proportion is but it is a big group (of mostly 18+ handicap golfers). And I am NOT talking about guys in their 60's. 

 

dave

[iacas]

1 hour ago, JohnB92 said:

My biggest issue with the rating system is how it mixes together course difficulty (how much space you have to land the shot, and penalty for missing) with course length.

 

No, it doesn't mix them: that's its SOLE purpose. Length is also difficulty. Longer is more difficult.

 

1 hour ago, JohnB92 said:

The way a good course rating system would work, you'd have to analyze what is the intended tee shot landing spot for each box, such that everyone is hitting the same general type of club into the green.

 

There's really no such thing as "intended."

 

1 hour ago, JohnB92 said:

It's not that the course is harder from farther back its that it's by definition a different course than the designer intended.

 

But… the course rating doesn't care what the designer intended. Nor should it.

 

1 hour ago, JohnB92 said:

Sorry guys, but there's almost no way that a 490-yard Par 5 (from the back tee) should ever be the #1 or #2 handicap hole on that side. It would need OB on both sides all the way with an island green and massive bunkers everywhere else.

 

Hole stroke indexes barely matter. You can assign them randomly and get almost the same results across the board.

 

1 hour ago, JohnB92 said:

Yep, I agree with that on the scratch player issue. Although I'd argue those guys probably shouldn't be playing the same tee box. Maybe the 238 and 251 guys could. But 217/251 = 86% that's a pretty large difference, probably 3 or 4 clubs in total on the same hole. Just like your example. That guy should be playing from tees farther up.

 

Length is a skill.

[Shilgy]

37 minutes ago, iacas said:

 

But… the course rating doesn't care what the designer intended. Nor should it.

 

Length is a skill.

I agree with your other replies as well….but it struck me that the course rating doesn’t care what the architect intended but to many folks that intent is why we “absolutely must” have a ball rollback.

[DaveLeeNC]

3 hours ago, Shilgy said:

I agree with your other replies as well….but it struck me that the course rating doesn’t care what the architect intended but to many folks that intent is why we “absolutely must” have a ball rollback.

Those seem to me to be totally separate things. The CR/length thing is about "how things currently are".  The ball rollback is about "how some people would like things to be". They are quite different in my  mind. 

 

dave

[JohnB92]

3 hours ago, iacas said:

 

No, it doesn't mix them: that's its SOLE purpose. Length is also difficulty. Longer is more difficult.

 

There's really no such thing as "intended."

 

But… the course rating doesn't care what the designer intended. Nor should it.

 

Hole stroke indexes barely matter. You can assign them randomly and get almost the same results across the board.
 

Length is a skill.

These statement's do not work together. You've said both that length is part of the course rating, but also the course rating doesn't mix length and course difficulty. Because "length is difficulty". You can't have it both ways, either it mixes them or it doesnt.

Length is not a "skill" in the traditional sense. If you asked DaveLee's 80-year-old man to "practice getting longer", that's not going to work. Length is only a skill if your swing isn't efficient, or you could be a lot stronger and choose not to workout. The only sense in which length is a skill, is when you're talking about events in which everyone is mandated to play the same tee box. Yes, in that case the longer player has an advantage but only when the length is actually significant enough to enable a different strategy or dramatically higher lofted clubs into greens (obviously it's easier to stick a PW close than a 6 iron). But when we are talking about comparing players who can choose different tee boxes, then you realize the course rating system vastly overemphasizes length. Which distorts handicaps.

As for there being no such thing as "intended". Obviously, they consider what clubs people will be hitting. That's where the whole concept of reachable Par 4s and Par 5s even comes from. Because the designer wanted to provide risk/reward opportunities. Every architect whose book I read talks about it. It's what the USGA is blabbering on about in their stupid rollback rule. 

Does anyone really thing course designers talk about tee box locations like this: "How far to make this Par 3 Mr. Designer?" "Oh, I don't know, 264 from the forward tee sounds reasonable. Maybe 301 from the back because I like that number." That makes no sense.
 

3 hours ago, DaveLeeNC said:

@JohnB92 You are ignoring a huge group of golfers - the old guys who have played all their lives and can't hit a driver 150 yards on the fly. I don't know what the proportion is but it is a big group (of mostly 18+ handicap golfers). And I am NOT talking about guys in their 60's. 

 

dave

These old guys are literally the group that is most distorted by the course rating system. These old guys have massive handicaps because they are playing the wrong tees. This is why the stereotype of the "sandbagging old man" is so common. They don't really even have to do it intentionally. The same guy, who needs an extra shot to reach all the non-par 3 holes will suddenly get a huge advantage when he plays from the correct tees. 

(113 / Slope Rating) x (Adjusted Gross Score - Course Rating - PCC adjustment) = Diff

 

(113/121) * (89-71.1) = 17.65 From White (one extra stroke per non-Par 3 to reach the green plus 3 over par for failed up/downs etc.)
(113/98) * (75-63.1) = 13.72 From Forward (No longer needs the extra stroke, so just the 3 over par)

Oh wow, look suddenly you see that the old guy apparently is now 4 shots better than he was before. Two people, with similar ball striking ability the only difference being age and strength are completely mismatched by the course rating system. Because in the course rating system, what drives the rating more than anything is length. I don't know of any course of 5900 yards that is rated harder than a course of 7100 yards. It's got to be a clown show of hazards, probably really beautiful to take pictures of though.

[DaveLeeNC]

@JohnB92 you keep referring to 'the correct tees' and I don't know what that means. To me this is simply a personal choice. I don't like not being able to reach some par 4's and don't like hitting nothing but 9i's or shorter into par 4's. And in some cases pace of play can be an issue here as well. But other folks are perfectly happy playing 10-12 'virtual' par 5's per round. If they can keep up then fine with me. 

 

You provided some kind of an example. I can do the math but cannot follow your logic. Can you elaborate. My analysis of my own situation is as follows. Back when I was in my late 50's and early 60's and played a lot and took golf seriously, I kept pretty detailed data on my play. The data was much like Arccos and I did my own personal kind of Strokes Gained analysis (this was prior to Brody's work). 

 

Once out of curiosity I did a calculation of how many strokes it took me to get into the hole against how far I was from the hole from the range of 90 yards to 200 yards out. And (in aggregate) I found that I was 0.1 strokes better every time I moved up 10 yards. 200 yards vs. 190 - 0.1 strokes difference. 100 yards vs. 90 yards - 0.1 strokes difference. The graph was surprisingly uniform and straight over that range. 

 

So I looked at one of the courses that I play frequently (par 72) and it is 5687 yards from the green tees, and 5212 from the red tees (difference of 475 yards). And I get 3 fewer strokes from the reds vs. the greens on that course. And my prior analysis of 0.1 strokes per 10 yards would say that I should get more like 5 fewer strokes from the red tees (0.1 x 475/10 = 4.75). Based on that analysis the system would seem to have too little sensitivity to length, not too much.

 

Our group has a choice between the two sets of tees and no one has chosen the red tees (except for one guy who cannot handle two forced water carries from the green tees). They don't feel like they get enough extra strokes from the shorter tees. 

 

And to use your par 3 analysis, if you move these guys up 20 yards they probably miss the green from either set of tees. They just have a bit shorter up/down from the shorter tees in the typical case. It isn't like 'if they can reach the green then they hit the green'. It is more a case of how long their up/down pitch shot is and this applies to all the holes - not just the par 3's. 

 

dave

 

ps. IMHO, the length sensitivity in the current system is fine. But the subtleties that differentiate an easy vs hard course (same length) is under calculated. 

Edited January 8 by DaveLeeNC

[iacas]

1 hour ago, JohnB92 said:

These statement's do not work together. You've said both that length is part of the course rating, but also the course rating doesn't mix length and course difficulty. Because "length is difficulty". You can't have it both ways, either it mixes them or it doesnt.

 

No, you misread. You said "My biggest issue with the rating system is how it mixes together course difficulty (how much space you have to land the shot, and penalty for missing) with course length."

 

Shorter, you said the course rating "mixes":

• difficulty
• length

I'm saying that those aren't mixed, because they're basically the same thing: the course rating is entirely about "difficulty," and that difficulty is almost itself entirely about the length.

 

Beyond that, I reject that the course rating system we have now isn't "good" and that whatever the "designer" intended should be a factor.

[StudentGolfer4]

9 hours ago, ThinkingPlus said:

Increasing the performance of scratch golfers will just lower the CRs across the board for most courses. It would increase the slope across the board for most courses unless a corresponding increase in bogey golfer distance was made. Not sure any of that makes ratings and slopes more accurate.

Yeah I see my thinking was flawed. Without derailing the thread, any ideas on how to scale down distance being such a large factor in course rating?

 

To me, distance plays too large or an impact. This is just something I’ve noticed in my own play. For reference, I play 6600-6800 most of the time. When I move back tees I end up posting lower index’s despite slightly higher scores. Moving up, higher index’s with a little lower scores. 

[Shilgy]

4 hours ago, DaveLeeNC said:

Those seem to me to be totally separate things. The CR/length thing is about "how things currently are".  The ball rollback is about "how some people would like things to be". They are quite different in my  mind. 

 

dave

I understand they are two separate things.  Although it could be said they want to get them closer to matching.  CR is based on the mystical scratch golf that hits it 250 off the tee. The rollback will make that closer to a reality.  
 

IMO the problem is the elite players will never again play the game “the way some people would like things to be.”  The old game of hit fairways and greens…lay up to your favorite yardage….two putts and move to the next tee has been proven to not be the best way to play elite golf.

 

  Even with a rollback the modern elites will hit it as far as they safely can and fire at the pins when reasonable.  It is just simply a more aggressive game partly brought on by analytics and partly by the depth on tour these days.  Par sucks.  At most events that misses the cut and players have also learned that it is better to run hot and cold than constant mediocre.

[iacas]

6 minutes ago, StudentGolfer4 said:

Yeah I see my thinking was flawed. Without derailing the thread, any ideas on how to scale down distance being such a large factor in course rating?

 

No, nor should it be IMO. It's intentionally given the weight it currently has.

 

6 minutes ago, StudentGolfer4 said:

To me, distance plays too large or an impact. This is just something I’ve noticed in my own play. For reference, I play 6600-6800 most of the time. When I move back tees I end up posting lower index’s despite slightly higher scores. Moving up, higher index’s with a little lower scores.

 

It is often slightly that way. And not just on longer tees, but on higher rated courses, too. More stats here: https://newsletter.loustagnergolf.com/p/do-the-tees-you-play-impact-your-index

[ThinkingPlus]

6 minutes ago, StudentGolfer4 said:

Yeah I see my thinking was flawed. Without derailing the thread, any ideas on how to scale down distance being such a large factor in course rating?

 

To me, distance plays too large or an impact. This is just something I’ve noticed in my own play. For reference, I play 6600-6800 most of the time. When I move back tees I end up posting lower index’s despite slightly higher scores. Moving up, higher index’s with a little lower scores. 

My understanding is that there is a base formula that converts distance to rating for men and another for women. It is the starting value for CR for a course during the rating process. Fractional strokes are added to or subtracted from the base CR based on obstacles, fairway width, penalty areas, etc... . You would need those formulae changed to modify how significant distance impacts CR.

[Newby]

3 hours ago, ThinkingPlus said:

My understanding is that there is a base formula that converts distance to rating for men and another for women. It is the starting value for CR for a course during the rating process. Fractional strokes are added to or subtracted from the base CR based on obstacles, fairway width, penalty areas, etc... . You would need those formulae changed to modify how significant distance impacts CR.

The length of a course is not used directly. It is based on the average shot length for a model scratch (and bogey) player. These are set distances and may not apply to a specific individual player.

eg

The "Length of 1st shot" for the scratch player is 250 yards

The "Length of 2nd shot" for the scratch player is 220 yards

The "Length of 1st shot" for the bogey player is 200 yards

The "Length of 2nd shot" for the bogey player is 170 yards

 

The difficulty elements are calculated by determining the potential obstacles in and around these 'target areas'

[ThinkingPlus]

5 hours ago, Newby said:

The length of a course is not used directly. It is based on the average shot length for a model scratch (and bogey) player. These are set distances and may not apply to a specific individual player.

eg

The "Length of 1st shot" for the scratch player is 250 yards

The "Length of 2nd shot" for the scratch player is 220 yards

The "Length of 1st shot" for the bogey player is 200 yards

The "Length of 2nd shot" for the bogey player is 170 yards

 

The difficulty elements are calculated by determining the potential obstacles in and around these 'target areas'

Apparently that was old information. The formulae are now based on individual hole effective length plus all the other factors. I am not sure how they work because they are not included in the manual. Even the hole rating examples don't provide a number. I'm not sure how the actual hole stroke values are truly generated.

[DaveLeeNC]

9 hours ago, Shilgy said:

Par sucks.  At most events that misses the cut and players have also learned that it is better to run hot and cold than constant mediocre.

 

Somebody (I think it was here but maybe not) used to track the "Pro Par Shooter" calculating the results by event of a guy who shoots par on every hole he plays on the PGA Tour.  This was at least 15 years ago, BTW. I don't recall the results but I would bet that the outcome would be very different now vs. then. 

 

dave

[Shilgy]

46 minutes ago, DaveLeeNC said:

 

Somebody (I think it was here but maybe not) used to track the "Pro Par Shooter" calculating the results by event of a guy who shoots par on every hole he plays on the PGA Tour.  This was at least 15 years ago, BTW. I don't recall the results but I would bet that the outcome would be very different now vs. then. 

 

dave

I recall that as well.  There were a couple events  that made the players season look good but it was mostly missed cuts.

[StudentGolfer4]

@DaveLeeNC @Shilgy

 

https://www.golfdigest.com/story/shoot-even-par-in-every-round-on-the-pga-tour-and-heres-how-you-would-have-done-during-the-2018-2019-season/amp

Sports illustrated has a similar article that was published at the end of the 2021 season. They excluded the par shooter from any majors and fed ex cup events. The number was 320k and good for 180th (both numbers rounded) on the money list. In their situation I seem to remember their golfer not trying to qualify for every event but obviously par isn’t getting it at the John Deer or other events where you have to go low. 

 

I saw a similar article 20 years ago or so and like you suggested, the results were quite different. That specific year the fictional player actually won the US Open! 

Edited January 8 by StudentGolfer4

[rogolf]

Why is this discussion about course rating now focusing on professionals?  Course rating is for handicaps, predominantly used to establish handicaps for amateurs.

[Newby]

4 hours ago, ThinkingPlus said:

Apparently that was old information. The formulae are now based on individual hole effective length plus all the other factors. I am not sure how they work because they are not included in the manual. Even the hole rating examples don't provide a number. I'm not sure how the actual hole stroke values are truly generated.

I must admit to oversimplification.

The effective playing length is determined from the measurement of each hole, adjusted for the impact of roll, wind, elevation changes, altitude, dog-legs and forced lay ups

 

 

This link may be of interest to some

https://golf.com/travel/how-golf-hole-rated-explained-usga-expert/

Edited January 8 by Newby

[ThinkingPlus]

1 hour ago, Newby said:

I must admit to oversimplification.

The effective playing length is determined from the measurement of each hole, adjusted for the impact of roll, wind, elevation changes, altitude, dog-legs and forced lay ups

 

 

This link may be of interest to some

https://golf.com/travel/how-golf-hole-rated-explained-usga-expert/

Agreed and the EPL serves as the basis for the initial CR for a hole, but that conversion from EPL to strokes is non-obvious and seems to be a closely held bit of information.

[rahatbmc]

On 1/8/2024 at 3:39 PM, ThinkingPlus said:

Agreed and the EPL serves as the basis for the initial CR for a hole, but that conversion from EPL to strokes is non-obvious and seems to be a closely held bit of information.

 

For example, assume a course with an EPL of 6600 yards has CR of 73.4

 

The course rating was calculated as follows:

 

6600 / 220            =   30.0

Rating Constant    =   40.9   (shots on or near the green)   

Scratch Obstacle  =     2.5

Value

Course rating         =  73.4

 

Taking 3 hypothetical holes (the Scratch Obstacle Value for the 18 holes will equal 2.5 and the CR for the 18 holes will equal 73.4)

 

EPL	360/220	1.64
RATING CONSTANT	40.9/18	2.27
SCRATCH OB VALUE		0.14
		4.05
EPL	160/220	0.73
RATING CONSTANT	40.9/18	2.27
SCRATCH OB VALUE		0.11
		3.11
EPL	575/220	2.61
RATING CONSTANT	40.9/18	2.27
SCRATCH OB VALUE		0.18
		5.07

 

My association provides the Club with this data which they can use to determine the stroke allocations.