Slope (GHIN) and the Good Doctor (and his contemporaries)

[George Blunt]

The slope at my home course has changed from 133 to 126 following a renovation.  If the architects of the Golden Age were around today, I think they would say that all things considered, this is a good thing. 

Recognizing that slope and course rating are an output of the design process, (or should be) would a great course on a great piece of land ideally have a slope of 113?  i.e. it is equally easy and equally hard for the scratch golfer as it is for the bogey golfer?

And if the answer is yes, why is there so much emphasis on slope, when the real measure of difficulty is course rating relative to par?

I ask these questions because the sky is falling in some parts of the world......

[Brent Hutto]

I've played courses with slope ratings of 114-116 a few times but can't recall any with 113 or less. Even 114-116 seems to be a sign of an extremely wide-open, relatively hazard-free course on very mild topography. Not sure that's really a good thing.

Why would you consider a slope of 113 a sign of quality rather than wide-openness? Those few low slope rating courses I've seen have been rather boring. Even a bit of contour of the greens probably gets a bit more than 113.

The average golf course in the USGA handicap system ratings is probably a bit over 120 so 113 is at the very, very low end of that spectrum.

[Garland Bayley]

The slope at my home course has changed from 133 to 126 following a renovation.  If the architects of the Golden Age were around today, I think they would say that all things considered, this is a good thing. 

Recognizing that slope and course rating are an output of the design process, (or should be) would a great course on a great piece of land ideally have a slope of 113?  i.e. it is equally easy and equally hard for the scratch golfer as it is for the bogey golfer?

And if the answer is yes, why is there so much emphasis on slope, when the real measure of difficulty is course rating relative to par?

I ask these questions because the sky is falling in some parts of the world......

If it was "equally easy and equally hard" then wouldn't everyone shoot the same score?
If it is on a great piece of land, doesn't that almost preclude it from having a slope of 113, unless it is excessively short?


Since the slope was reduced so much, and since slope is highly dependent on length, what did they do to get the slope reduced? Add a shorter set of tees? Furthermore, you don't mention course rating. Did it stay the same?

[George Blunt]

Slope measures relative difficulty, not outright difficulty.

A slope of 113 represents a course of average difficulty according to the USGA.

And yes, the course rating also come down close to a full shot because one of the par 5's was converted to a par 4.

[Ed Brzezowski]

The " slope" is the angle or gradient between a scratch player and a bogey player.  Scratch might be a 71 and bogey a 90. The slope is the angle of the line drawn between these two scores on a graph. The closer the scores are the lower the slope, the more disparity the " higher" the slope.

[Brent Hutto]

A slope of 113 represents a course of average difficulty according to the USGA.

Whoever at USGA said that misspoke. The average of slope ratings among courses in the handicap system is far higher than 113, I'd guess around 120 or a bit higher. And there are at least five times as many courses higher than 113 as lower than 113. I've never even seen mention of a course with a slope rating less than about 108 (five points less than 113) yet almost every course I'm familiar with is sloped in the 120's or 130's (10 to 20 points higher than 113).

A slope rating of 113 denotes a course so devoid of hazards and other high-handicapper difficulties as to be almost certainly bland or boring. Hard to see that meeting any conception of quality or desirability in design.

[Philip Caccamise]

A slope of 113 represents a course of average difficulty according to the USGA.

Whoever at USGA said that misspoke. The average of slope ratings among courses in the handicap system is far higher than 113, I'd guess around 120 or a bit higher. And there are at least five times as many courses higher than 113 as lower than 113. I've never even seen mention of a course with a slope rating less than about 108 (five points less than 113) yet almost every course I'm familiar with is sloped in the 120's or 130's (10 to 20 points higher than 113).

A slope rating of 113 denotes a course so devoid of hazards and other high-handicapper difficulties as to be almost certainly bland or boring. Hard to see that meeting any conception of quality or desirability in design.

Formulaically speaking, George is right.

It's (Player Score - Course Rating) * (113 / Slope) = Handicap Index

So a 113 slope means whatever your score was minus the course rating is your handicap, regardless of your magnitude over par. Now whether the "average" course in the database is a 113 (from equivalent yardage) is up for debate. From 6,000 yards, I don't think it is either the mean, median, or mode, so the USGA may need to revise their wording to "baseline" versus average.

[Brent Hutto]

That's why I said "misspoke". The "slope rating" is an abstracted number from a two-parameter curve-fit, it has various interpretations but no inherent meaning...there are no units to the scale. The value 113 is the "norm" or "standard" or "baseline" or whatever word you'd care to use to indicate its use in that forumla. But an "average", it is not. It is not the mean or any group of values nor is any kind of measure of central tendency. It's just a number in a formula and it drives me f---ing nuts every time I see that "average slope rating is 113" meme trotted out.

But then again, there is so much FAIL in the entire handicap system and its nomenclature that one hardly knows where to start...

[Garland Bayley]

Slope measures relative difficulty, not outright difficulty.

A slope of 113 represents a course of average difficulty according to the USGA.

And yes, the course rating also come down close to a full shot because one of the par 5's was converted to a par 4.

I understand your statement to mean that a hole was shortened, so it no longer is a par 5, but now is a par 4.

It seems to me that you reduced the length of the course, thereby reducing the two ratings. It has nothing to do with the relative merits of the architecture. The ODGs and the NLGs would say nothing other than it's slightly different now. Architecture is not measured by slope. Slope is an artifact of par and handicapping, neither of which have anything to do with quality architecture.

[Andrew Buck]

Slope measures relative difficulty, not outright difficulty.

A slope of 113 represents a course of average difficulty according to the USGA.

And yes, the course rating also come down close to a full shot because one of the par 5's was converted to a par 4.

I believe the USGA has commented that they now recognize average difficulty to be around 120, and 113 was just what they estimated at the time that they developed the system. 

[Jim Nugent]

A slope of 113 represents a course of average difficulty according to the USGA.

I don't think that's right.  Slope as I understand it is defined as (BR - CR) x 5.381, where BR = Bogey Rating, and CR = Course Rating.  i.e. slope is supposed to show how hard a course is for the average player compared to the scratch player.  But it says nothing about how easy or hard any course actually is.  

e.g. a course could be damn hard, say with a CR of 78, yet still have 113 slope.  In that case, BR would equal 99.  I don't know the formula for handicaps, but I think George is more or less right, when he says 113 slope means equal difficulty: equally hard considering your handicap, that is.  

To repeat my old refrain: drop slope altogether.  Instead publish both CR and BR.  Everyone who plays the course will know exactly how hard it's supposed to be, both for scratch and bogey players.  

[George Blunt]

Sorry, I didn't really want this to be all about the validity or otherwise of slope.  I was really trying to get to the heart of whether or not a course that presents the same level of difficulty to the scratch golfer as it does to the bogey golfer is in keeping with some of the principles of classical architecture.  And from this I was curious to get peoples' thoughts on slope as a valid measure for this, which probably confused the topic.

[Garland Bayley]

You can have a marvelous course with a course rating of 61 and a slope rating of 93. And, you can have a marvelous course with a course rating of 78 and a slope rating of 155. These ratings have nothing to do with architectural quality.

[Pete_Pittock]

Sorry, I didn't really want this to be all about the validity or otherwise of slope.  I was really trying to get to the heart of whether or not a course that presents the same level of difficulty to the scratch golfer as it does to the bogey golfer is in keeping with some of the principles of classical architecture.  And from this I was curious to get peoples' thoughts on slope as a valid measure for this, which probably confused the topic.

There are a number of reasons why this could have happened, and either architecturel or maintenance practices could contribute.
      The original slope rating might not have been accurate
      Bunkers could be taken out of the landing areas for bogey golfers (leaving the CR the same, but lowering slope).
      High grass or undermainainedted areas could be tajeb out of the LZ of bogey golfers.
      Redesign away from OB areas.
      How water hazards interact with distance challenged golfers (DCG).
      Opening up layup areas for DCGs which will unlikely be used by scratch players
      Widening entrance area to greens to allow run-up shots.     

[Brent Hutto]

Your use of the word "same" here is confusing me. Any golf course is more difficult for a 20-handicapper than a scratch golfer. And if it were even possible to design one otherwise it would be a very strange place.

[James Bennett]

George

Slope has been introduced into Australian golf now, so i have some idea what you are referring to.

I have played enjoyable courses with a slope up to 130.  I am yet to see a course as enjoyable with a slope above 130. These are typically good courses with a VCR at or above par.

James B

[George Blunt]

Brent, apologies for the confusion. Blame my accent!  "Same" in this context references the ease or difficulty of a scratch golfer making a par vs. a bogey golfer making a bogey.

James, I was aware that slope, like cane toads, had taken over Australia. Part of my questioning stems from RMGC West slope, and the general outcry over it being low. My thought is that Mackenzie would have been pleased.

[Brent Hutto]

Well that gets me back full circle to my original thought on it. I've played a few courses just a few points over 113 slope ratings. They were not distinguished design-wise. Just about every fun and interesting course I've encountered has been in the 121-136 range of slope rating (from the tees I was playing). And I'm a bogey golfer. So I don't think avoiding the bunkers, green contours and whatever other elements are associated with 120+ slope ratings is a good thing.

Nothing wrong with a plain, dull or boring course. It's still better than being at my desk working and I can have a good time most anywhere on a fine day with fine companions playing golf. But to score a 113 or less seems to mean avoiding a lot of interesting design features.

[John Connolly]

George,

I asked a similar question in a thread not too long ago. And received some interesting replies. As I recall the overriding message was, course difficulty and architectural merit need not be coupled. Having said that, I think there is a scatter plot out there somewhere which would show a correlation between course difficulty and perceived quality. I think there would a level of difficulty where the "quality" y axis would flatten out but early on in the "best fit" line for the scatter plot, the relationship would be linear.

I realize that slope is an imperfect measure as it really is just a subjective value by which course difficulty for bogey players relative to scratch players is quantified. And although it's done by raters using a set of predetermined criteria, the formula uses those criteria to predict what the score would have been. But instead of having a 100 bogey golfers go play the course, they estimate. Seems at least partially reasonable. We use use formulas in everyday life to predict events (weather, retirement funds, the NFL draft! etc). So why not predicting a bogey golfer's round?

I am doubtful that a course would be considered architecturally great if it had a low slope. If you want to go to the top of the architectural mountain, here is a top 10 listing. The slopes from member tee equivalents (around 6500 to 6700) are as follows:

PV 153
ANGC only Old Tom knows for sure
CPC 140
Shinny 138
Oakmont 134
Merion East 149
Pebble 136
Winged Foot West 134
Sand Hills not rated near as I can tell
Fishers Island 143

I'm not advocating slope as the best or even a good measure of gca. But I am saying a smart statistician somewhere at MIT would be able to demonstrate they're correlative. Put another way, an architecturally respected course will probably be considered hard enough by bogey golfers relative to scratch players to have a higher slope than a course that is not regarded. The converse is not necessarily true - a course with a high slope could be a gca train wreck.
 

[Pete_Pittock]

slope is a function of the USGA mandating that every score be posted for handicap. The world was perfectly happy with the SSS system, or its equivalent.

[James Bennett]

James, I was aware that slope, like cane toads, had taken over Australia. Part of my questioning stems from RMGC West slope, and the general outcry over it being low. My thought is that Mackenzie would have been pleased.

excellent post George. 

Royal Adelaide comes out at about 130 from the white tees, and might be 132 from the blues.
Kooyonga has a higher slope (about 136) which I think is right (ie that the slope is more severe) as the fairway width, green size and severity of rough penalty all seem to be higher at Kooyonga than at RA.
I am at RM West on this Saturday - I might make a further comment on their slope and their enjoyability after that.  The forecast is for a lovely, suuny, late autumn day - just perfect.

James B

[Patrick_Mucci]

The slope at my home course has changed from 133 to 126 following a renovation. 
If the architects of the Golden Age were around today, I think they would say that all things considered, this is a good thing. 

Why ?

Recognizing that slope and course rating are an output of the design process, (or should be) would a great course on a great piece of land ideally have a slope of 113? 

No

i.e. it is equally easy and equally hard for the scratch golfer as it is for the bogey golfer?

Give us an example of a hole and a course that fit that mandate.

And if the answer is yes, why is there so much emphasis on slope, when the real measure of difficulty is course rating relative to par?

I ask these questions because the sky is falling in some parts of the world......

[Tom_Doak]

Reducing golf course design to numbers is really a waste of time.  The Slope System is quite imperfect when it comes to areas such as strategy and angles of approach ... it assumes that people are playing from the middle of the fairway and assesses how hard it is to get there.

You can have a marvelous course with a course rating of 61 and a slope rating of 93. And, you can have a marvelous course with a course rating of 78 and a slope rating of 155. These ratings have nothing to do with architectural quality.

Garland:  In theory, that's true, but in practice, can you name an example of your first type?

[Niall C]

"If the architects of the Golden Age were around today, I think they would say that all things considered, this is a good thing"

I wonder. Would they really be happy at an attempt to reduce the value of their design to a number ?

Niall

[Michael Whitaker]

"If the architects of the Golden Age were around today, I think they would say that all things considered, this is a good thing"

I wonder. Would they really be happy at an attempt to reduce the value of their design to a number ?

Niall

Depends on whether their designs got a "favorable" number or not. If they perceived it beneficial they would include the numbers in their promotional literature... if not, they would bemoan the system as frivolous.