Course Ratings and Slope, Difficulty, and Hole Stroke Index

[iacas]

I've been meaning to write this for awhile, and since the World Handicap System (WHS) is coming to most of the world this year, now's as good a time as any.

This article will assume that you're semi-familiar with the the concepts of course rating and slope, and really seeks to expel some basic myths and misconceptions.

Course Ratings Are the Primary Determinant of "Difficulty"

As you should know, when a golf course is rated (for "difficulty"), many, many, many numbers are generated for each hole. Most of these numbers are pretty objective: the width of the fairway, the length of the hole, elevation changes, the diameter of the green, the depth and size of green side bunkers, etc. A few are subjective, like "how difficult is it to escape if you hit your ball into those trees"?

Two numbers come out of this calculation: a scratch rating and a bogey rating.

The scratch rating is defined as the score a scratch golfer should shoot on rounds where he plays to his handicap index (of 0.0). The bogey rating is the same for a "bogey golfer," (who, oddly, isn't an 18.0 index, but closer to a 20.0, as they're about a 20 course handicap on a 113-slope course).

So, we have two numbers: the score for a scratch golfer and the score for a bogey golfer.

Some basic linear algebra and geometry are used as such:

• Two points define a line.
• We plot those two points on a graph, and draw a line connecting them.
• This line has a "slope" that tells us the "slope rating" of that set of tees.

Remember y = mx + b?

In this case, y is the course handicap, m is the slope (slope rating/113), x is the handicap index, and b is the course rating.

And that's just what we see in a graph:

This is a set of tees with a rating of 72.0 (note that I consider all tees to be par 72 for the simplicity's sake in this article) and a slope of 113.

y = mx + b
CH = 113/113 * (HI) + 0
CH = 1 * HI
CH = HI

This should make sense: on a 72.0 (par 72) course with a slope of 113, we have a basic line with a slope of 1. These golfers should shoot, on average for the eight rounds that count toward their handicap index, these scores:

HI	Score	To Par
0.0	72	0
3.0	75	+3
15.0	87	+15
+2.0	70	-2

We could keep the same slope and make the course rating 69.0, and the course would instantly be three shots easier for every golfer. And this leads into what seems to be the biggest misconception. Too many people look at one number - the slope - and use that to determine what the "difficulty" of the course is.

But that fails, because lines are defined by more than their slope: the y-intercept matters. Imagine a course with a rating of "100.0" and a slope of "102." Nobody in their right minds would say that course is "easier" than a 72.0/144-rated course.

Here's a chart of four fictitious golf courses:

The graph of the course handicaps (note that rounding creates some "bumps" in the lines when the slope is not the whole number 1 (113/113):

Showing the trend lines much more heavily:

 

What these graphs show you is that course "difficulty" is a function of both the "m" and the "b" - the course rating AND the slope.

Look at the 74.0/118 course (grey) and the 72.0/136 course (green). Despite a difference of 18 in their slope, for the majority of these golfers, the 74.0/118 course plays "more difficult" due to the higher starting point of 74.0. It's not until you get out to about a 14.0 index that you start to see the expected scores for the 72.0/136 course take over due to the slope.

Look at all of the lines, in fact: the yellow line (69.0/140) remains lower for most of the graph than even the two 72.0 courses (blue 113, green 136), and well below the grey course (74.0/118). But this is because the course rating varies by 3 and 5 (69 to 72 and 74), while the slope can only make up fractions of a stroke (140/113 =~ 1.24 course handicap strokes per 1.0 strokes handicap index).

So, the course rating is the primary determinant of a course's difficulty.

The slope tends to matter in only two situations:

• The difference in handicap indexes is LARGE.
• The course ratings are quite close together.

The first matters because the slope has more time to keep adding "tenths of a shot" to the course handicap. The second matters because it's easier to overcome a deficit of 0.2 or 0.3 than a deficit of 2.4 or 3.1.

But What about + Handicaps?

Next look at the 72.0/113 course in blue. This course crosses the 72.0/136 (green) course at 0.0, and for everyone with a handicap on the opposite side from + handicaps, the green course is "more difficult" than the blue course.

But on the left side of scratch, the green course is "easier" than the blue course? Why is that?

Because the slope is the relative difference in difficulty between a good player and a worse player.

The "0.0" seems to throw people off, but the fact that we have + handicaps tells you that's not the absolute lowest anyone can go. Think of it this way: if a 13.0 gets 6 shots from an 8.0 due to the slope, then a +5.0 should give up six shots to a 0.0 too (there are occasionally rounding things that change this a little, on either side). The slope is the same, and so a change in "x" (the handicap index) should result in the same difference in course handicap (the y axis) because the slope of the line is constant.

Another way to think of it: add the course's par to the course handicap. If we called scratch golfers "72.0 golfers" on a 72.0-rated course, then you can see how a "67.0-rated golfer" should give up 5 shots to a "72.0 golfer" on a 72.0/113 course, and six shots to a 72.0/140 course.

67.0 * 140/113 = 83
72.0 * 140/113 = 89

Right?

The same math, essentially:

-5.0 * 140/113 = -6
0.0 * 140/113 = 0

Make sense?

Good. The final thing…

Stroke Indexes and "Hole Difficulty"

I'll try to keep this one short: the "stroke index" (handicap index) of the hole is NOT the "difficulty" of the hole.

It's a measure of where the higher handicapper is most likely to need a stroke against a lower handicapper.

Why are (or were, see the note below) par fives often the lower stroke index holes? Because:

• Better players tend to birdie or par them.
• Worse players tend to bogey them.

The increased distance gives a better player more chances to recover and more of an opportunity to show off their length. Consider the example of a one-foot putt versus a 50-foot putt: both the high and low handicapper are just going to tap in all the time on the one-footer, but the low handicap player is going to win a match of 50-foot putts against the worse player much more often.

To good players, par threes — often the high stroke index holes — are the "more difficult" holes relative to par. That's why they're traditionally the higher stroke index holes - the high handicapper isn't as likely to need a stroke against the better player.

Note: This stuff used to be calculated by courses literally turning in about 400 scorecards, which would all be entered hole-by-hole, and computed to determine which holes had the largest gaps between "better players" and "worse players." The holes would be ranked, the data massaged so that the first six holes didn't give out the strokes 1 to 5, and away we'd go.

The USGA and R&A have learned, however, that the actual location of strokes doesn't really matter all that much, so long as they're not clustered (like the example of stroke index holes 1-5 in the first six holes of the course). So, to make things simpler, they've come up with the idea of "triads" and are assigning stroke indexes via that method. You can read more about that method here: https://www.usga.org/content/usga/home-page/handicapping/roh/Content/rules/Appendix E Stroke Index Allocation.htm. In essence, it maintains the idea of the relative difficulty* while making things much simpler and not requiring all the "massaging" that was done before, and adequately spreads out the low- and high-stroke-index holes so that matches are not decided in the first six holes or before the last six holes are reached.

* To quasi-make up some numbers, a par 3 is likely to be 3.3 versus 3.5, for a total of 0.8 above par, while a par five is likely to be 4.9 versus 6.3, for a total of 1.2 above par.

[dagolfer18]

Very interesting! Here’s something I’ve been curious about for a long time now: why are the even-numbered stroke indexes usually on one nine and the odd-numbered indexes on the other?

[David in FL]

28 minutes ago, dagolfer18 said:

Very interesting! Here’s something I’ve been curious about for a long time now: why are the even-numbered stroke indexes usually on one nine and the odd-numbered indexes on the other?

The last paragraph, including the provided link, answers your question in detail...

[iacas]

3 hours ago, David in FL said:

The last paragraph, including the provided link, answers your question in detail...

Yes, @dagolfer18: https://www.usga.org/content/usga/home-page/handicapping/roh/Content/rules/Appendix E Stroke Index Allocation.htm.

[RFKFREAK]

On 4/11/2020 at 3:20 PM, iacas said:

I've been meaning to write this for awhile, and since the World Handicap System (WHS) is coming to most of the world this year, now's as good a time as any.

This article will assume that you're semi-familiar with the the concepts of course rating and slope, and really seeks to expel some basic myths and misconceptions.

Course Ratings Are the Primary Determinant of "Difficulty"

As you should know, when a golf course is rated (for "difficulty"), many, many, many numbers are generated for each hole. Most of these numbers are pretty objective: the width of the fairway, the length of the hole, elevation changes, the diameter of the green, the depth and size of green side bunkers, etc. A few are subjective, like "how difficult is it to escape if you hit your ball into those trees"?

Two numbers come out of this calculation: a scratch rating and a bogey rating.

The scratch rating is defined as the score a scratch golfer should shoot on rounds where he plays to his handicap index (of 0.0). The bogey rating is the same for a "bogey golfer," (who, oddly, isn't an 18.0 index, but closer to a 20.0, as they're about a 20 course handicap on a 113-slope course).

So, we have two numbers: the score for a scratch golfer and the score for a bogey golfer.

Some basic linear algebra and geometry are used as such:

• Two points define a line.
• We plot those two points on a graph, and draw a line connecting them.
• This line has a "slope" that tells us the "slope rating" of that set of tees.

Remember y = mx + b?

In this case, y is the course handicap, m is the slope (slope rating/113), x is the handicap index, and b is the course rating.

And that's just what we see in a graph:

This is a set of tees with a rating of 72.0 (note that I consider all tees to be par 72 for the simplicity's sake in this article) and a slope of 113.

y = mx + b
CH = 113/113 * (HI) + 0
CH = 1 * HI
CH = HI

This should make sense: on a 72.0 (par 72) course with a slope of 113, we have a basic line with a slope of 1. These golfers should shoot, on average for the eight rounds that count toward their handicap index, these scores:

HI	Score	To Par
0.0	72	0
3.0	75	+3
15.0	87	+15
+2.0	70	-2

We could keep the same slope and make the course rating 69.0, and the course would instantly be three shots easier for every golfer. And this leads into what seems to be the biggest misconception. Too many people look at one number - the slope - and use that to determine what the "difficulty" of the course is.

But that fails, because lines are defined by more than their slope: the y-intercept matters. Imagine a course with a rating of "100.0" and a slope of "102." Nobody in their right minds would say that course is "easier" than a 72.0/144-rated course.

Here's a chart of four fictitious golf courses:

The graph of the course handicaps (note that rounding creates some "bumps" in the lines when the slope is not the whole number 1 (113/113):

Showing the trend lines much more heavily:

 

What these graphs show you is that course "difficulty" is a function of both the "m" and the "b" - the course rating AND the slope.

Look at the 74.0/118 course (grey) and the 72.0/136 course (green). Despite a difference of 18 in their slope, for the majority of these golfers, the 74.0/118 course plays "more difficult" due to the higher starting point of 74.0. It's not until you get out to about a 14.0 index that you start to see the expected scores for the 72.0/136 course take over due to the slope.

Look at all of the lines, in fact: the yellow line (69.0/140) remains lower for most of the graph than even the two 72.0 courses (blue 113, green 136), and well below the grey course (74.0/118). But this is because the course rating varies by 3 and 5 (69 to 72 and 74), while the slope can only make up fractions of a stroke (140/113 =~ 1.24 course handicap strokes per 1.0 strokes handicap index).

So, the course rating is the primary determinant of a course's difficulty.

The slope tends to matter in only two situations:

• The difference in handicap indexes is LARGE.
• The course ratings are quite close together.

The first matters because the slope has more time to keep adding "tenths of a shot" to the course handicap. The second matters because it's easier to overcome a deficit of 0.2 or 0.3 than a deficit of 2.4 or 3.1.

But What about + Handicaps?

Next look at the 72.0/113 course in blue. This course crosses the 72.0/136 (green) course at 0.0, and for everyone with a handicap on the opposite side from + handicaps, the green course is "more difficult" than the blue course.

But on the left side of scratch, the green course is "easier" than the blue course? Why is that?

Because the slope is the relative difference in difficulty between a good player and a worse player.

The "0.0" seems to throw people off, but the fact that we have + handicaps tells you that's not the absolute lowest anyone can go. Think of it this way: if a 13.0 gets 6 shots from an 8.0 due to the slope, then a +5.0 should give up six shots to a 0.0 too (there are occasionally rounding things that change this a little, on either side). The slope is the same, and so a change in "x" (the handicap index) should result in the same difference in course handicap (the y axis) because the slope of the line is constant.

Another way to think of it: add the course's par to the course handicap. If we called scratch golfers "72.0 golfers" on a 72.0-rated course, then you can see how a "67.0-rated golfer" should give up 5 shots to a "72.0 golfer" on a 72.0/113 course, and six shots to a 72.0/140 course.

67.0 * 140/113 = 83
72.0 * 140/113 = 89

Right?

The same math, essentially:

-5.0 * 140/113 = -6
0.0 * 140/113 = 0

Make sense?

Good. The final thing…

Stroke Indexes and "Hole Difficulty"

I'll try to keep this one short: the "stroke index" (handicap index) of the hole is NOT the "difficulty" of the hole.

It's a measure of where the higher handicapper is most likely to need a stroke against a lower handicapper.

Why are (or were, see the note below) par fives often the lower stroke index holes? Because:

• Better players tend to birdie or par them.
• Worse players tend to bogey them.

The increased distance gives a better player more chances to recover and more of an opportunity to show off their length. Consider the example of a one-foot putt versus a 50-foot putt: both the high and low handicapper are just going to tap in all the time on the one-footer, but the low handicap player is going to win a match of 50-foot putts against the worse player much more often.

To good players, par threes — often the high stroke index holes — are the "more difficult" holes relative to par. That's why they're traditionally the higher stroke index holes - the high handicapper isn't as likely to need a stroke against the better player.

Note: This stuff used to be calculated by courses literally turning in about 400 scorecards, which would all be entered hole-by-hole, and computed to determine which holes had the largest gaps between "better players" and "worse players." The holes would be ranked, the data massaged so that the first six holes didn't give out the strokes 1 to 5, and away we'd go.

The USGA and R&A have learned, however, that the actual location of strokes doesn't really matter all that much, so long as they're not clustered (like the example of stroke index holes 1-5 in the first six holes of the course). So, to make things simpler, they've come up with the idea of "triads" and are assigning stroke indexes via that method. You can read more about that method here: https://www.usga.org/content/usga/home-page/handicapping/roh/Content/rules/Appendix E Stroke Index Allocation.htm. In essence, it maintains the idea of the relative difficulty* while making things much simpler and not requiring all the "massaging" that was done before, and adequately spreads out the low- and high-stroke-index holes so that matches are not decided in the first six holes or before the last six holes are reached.

* To quasi-make up some numbers, a par 3 is likely to be 3.3 versus 3.5, for a total of 0.8 above par, while a par five is likely to be 4.9 versus 6.3, for a total of 1.2 above par.

[Morgan Mullins]

Just curious, is there an average course rating?  Or a rating range that many/most courses fall within? Thanks.

[Carl3]

I went into my first season in WNY with a 5.8 HI and joined a club and saw my index climb to over 10 and it could have been higher if not for the soft cap that limits the upward rise. Some of it could have been the stress in moving, playing a little less and not playing with a regular group with the friendly, competitive rivalries. However, some of it I had wanted to attribute to perhaps the course having a lower slope and index than warranted. From the back tees the par 72 course plays 6,523 yards has a rating of 70.8 and a slope of 123. I read though the explanation that @iacas provided.

I did hear that perhaps for some courses, much of this evaluation could be done with pen and paper and that a course rater is not obligated to play the course. Elements of the course that I believe make this particular more difficult are some elevated greens, some of which are small and have some severe slopes. I also felt that the greens were kept at a super high stimp and some of the regular pin placements were severe. I had heard a rumor that a junior golfer had come in decades ago and had destroyed the course with a super low score and the greenskeep had vowed that this would never happen again. Now this is all speculation and perhaps rationalization of my poor performance, but I do have some interesting data that I would like to share and get some opinions on.

My district senior championship was played there last year and I show the top 24 finishers with their handicap index, their scores, differentials and then the average differential minus their handicap index. I have highlighted the finishers who were playing the event on their home course. As you can see these three players did super-well compared to their index and no one else seemed to come close to this performance. Another observation is that the winner and the 5th place finisher who are 5.0 and 4.8 index respectively blew away golfers with much, much better indexes. I don't think that this could be all due to home-course advantage. The 17th place finisher is a 10.6 and beat a scratch golfer and a 2.2 index. Part of this could be attributed to the course being more challenging than the slope and index would indicate. This would also tend to make the home course players have a higher HI than indicated. 

The winner had an amazing two rounds and I was wondering what the probability is for him shooting two rounds in a row below his index especially since it is his home course where he plays all of the time. 5th place shot super close to his index too.

Any observations and thoughts would be appreciated. The reason I bring this up is that I may have a chance to rejoin this coming season and am weighing the pros/cons.

Edited February 8, 2022 by Carl3

[iacas]

1 hour ago, Carl3 said:

I did hear that perhaps for some courses, much of this evaluation could be done with pen and paper and that a course rater is not obligated to play the course. Elements of the course that I believe make this particular more difficult are some elevated greens, some of which are small and have some severe slopes.

Course raters, even if they don't play the course, still TOUR the course and measure everything and take note of everything. They'll roll balls on the greens, stop and look at recovery shots from the trees, look at the depth of the bunkers or the elevation of the greens, visibility issues, etc.

So everything (and more) that you listed is noted/measured/included.

1 hour ago, Carl3 said:

My district senior championship was played there last year and I show the top 24 finishers with their handicap index, their scores, differentials and then the average differential minus their handicap index. I have highlighted the finishers who were playing the event on their home course. As you can see these three players did super-well compared to their index and no one else seemed to come close to this performance. Another observation is that the winner and the 5th place finisher who are 5.0 and 4.8 index respectively blew away golfers with much, much better indexes. I don't think that this could be all due to home-course advantage. The 17th place finisher is a 10.6 and beat a scratch golfer and a 2.2 index. Part of this could be attributed to the course being more challenging than the slope and index would indicate. This would also tend to make the home course players have a higher HI than indicated. 

The winner had an amazing two rounds and I was wondering what the probability is for him shooting two rounds in a row below his index especially since it is his home course where he plays all of the time. 5th place shot super close to his index too.

Any observations and thoughts would be appreciated. The reason I bring this up is that I may have a chance to rejoin this coming season and am weighing the pros/cons.

You can't just multiply them, but your first guy shot 1.1 and 3.9 better… which is 10:1 odds and 57:1 odds.

[Carl3]

Just started helping the Ohio Golf Association with course rating. Maybe 90 to 95% of the rating is based on distance and finally found the formulas used. For the scratch rating you divide the course length by 220 and then add 40.9. So tees at 6,000 yards would start with a scratch rating of 68.2. For the bogey rating you would divide by 160 and add 50.7 to yield 88.4. Now the balance of the calculations (the other 5%) take into account obstacles, hazards, green contour, green speed, etc. Then the difference between the scratch and bogey rating is multiplied by 5.381 to get the slope.

I had always wondered how they came up with the initial scratch rating minus the obstacle/dificulty part.

[mdl]

4 hours ago, Carl3 said:

Just started helping the Ohio Golf Association with course rating. Maybe 90 to 95% of the rating is based on distance and finally found the formulas used. For the scratch rating you divide the course length by 220 and then add 40.9. So tees at 6,000 yards would start with a scratch rating of 68.2. For the bogey rating you would divide by 160 and add 50.7 to yield 88.4. Now the balance of the calculations (the other 5%) take into account obstacles, hazards, green contour, green speed, etc. Then the difference between the scratch and bogey rating is multiplied by 5.381 to get the slope.

I had always wondered how they came up with the initial scratch rating minus the obstacle/dificulty part.

I always knew it as high but never that distance was 90-95% of rating! That has always played to my advantage. I never have but I could totally vanity cap myself by playing **super** long courses that are otherwise super easy. There was one course like that in LA that I used to play that helped my cap like that. The back tees were close to 7k yards, but otherwise the course was incredibly easy. Wide open, misses almost always had a play at the green from the adjacent hole, flat greens, not challenging green complexes, etc. But it got a high rating because it was so long. So I could swing hard, spray and pray, and score well (relative to my handicap).

[Carl3]

9 hours ago, mdl said:

I always knew it as high but never that distance was 90-95% of rating! That has always played to my advantage. I never have but I could totally vanity cap myself by playing **super** long courses that are otherwise super easy. There was one course like that in LA that I used to play that helped my cap like that. The back tees were close to 7k yards, but otherwise the course was incredibly easy. Wide open, misses almost always had a play at the green from the adjacent hole, flat greens, not challenging green complexes, etc. But it got a high rating because it was so long. So I could swing hard, spray and pray, and score well (relative to my handicap).

I think 95% is more accurate. The leader of our course rating program shot from the hip and said 90%, but I recently read elsewhere that it is more like 95%. So we spend 4 hours or more on a course with a team of 6 to 8 people to figure out the last few rating strokes as to whether they exist or not due to difficulty.

I credit this site/forum for getting my interest up in volunteering for my state association. I am marshalling for the US Mid Am qualifier later this morning 15 min from my home. We get shirts, hats, 1/4 zips, a cart with our name on it, a radio, lunch and unlimited snacks all while watching some great golfers. 🙂

Edited August 13 by Carl3

[Shindig]

12 hours ago, mdl said:

I always knew it as high but never that distance was 90-95% of rating! That has always played to my advantage. I never have but I could totally vanity cap myself by playing **super** long courses that are otherwise super easy. There was one course like that in LA that I used to play that helped my cap like that. The back tees were close to 7k yards, but otherwise the course was incredibly easy. Wide open, misses almost always had a play at the green from the adjacent hole, flat greens, not challenging green complexes, etc. But it got a high rating because it was so long. So I could swing hard, spray and pray, and score well (relative to my handicap).

Woodley Lakes?  I was wondering why it's rated where it is, since it doesn't seem more difficult (if anything, easier) than Encino/Balboa.   It makes so much more sense now.

3 hours ago, Carl3 said:

I think 95% is more accurate. The leader of our course rating program shot from the hip and said 90%, but I recently read elsewhere that it is more like 95%. So we spend 4 hours or more on a course with a team of 6 to 8 people to figure out the last few rating strokes as to whether they exist or not due to difficulty.

I credit this site/forum for getting my interest up in volunteering for my state association. I am marshalling for the US Mid Am qualifier later this morning 15 min from my home. We get shirts, hats, 1/4 zips, a cart with our name on it, a radio, lunch and unlimited snacks all while watching some great golfers. 🙂

Sounds like I should volunteer for my state association too.  I used to get some cool gear like that (well, not the cart) when I volunteered for check-in and will call at the L.A. Open, back when I lived there.

[mdl]

1 hour ago, Shindig said:

Woodley Lakes?  I was wondering why it's rated where it is, since it doesn't seem more difficult (if anything, easier) than Encino/Balboa.   It makes so much more sense now.

I was thinking of Encino, but yeah Woodley Lakes played a similar role.

[iacas]

It's rarely 95%. At some courses it's not even 90%.

[Carl3]

4 hours ago, iacas said:

It's rarely 95%. At some courses it's not even 90%.

I took a look at a 6,300 yard fairly easy course and it was 99% distance and then a 6,800 yard more challenging course and it was 97% distance. Do you have an example of one less that 95% or 90%? Maybe I am misunderstanding something.

(6,310/220) + 40.9 = 69.6. Course rating is 70.0 with a 120 slope. Less than 1% other factors?

(6,804/220) + 40.9 = 71.8. Course rating is 74.0 with a 140 slope. About 3% other factors?

These are more extreme:

(4,698/220) + 40.9 = 62.3. Course rating is 62.7 with a slope of 101. 

(7,569/220) + 40.9 = 75.3. Course rating is 77.4 with a slope of 155.

So long hard courses are 97% length and short easy courses are 99% length in these examples. I am new to this so maybe I am all wet.

 

[iacas]

That's not the right way to look at it, because you're not going to have a rating of 55 or something for even a 6500-yard par 72. There's a minimum rating (depending on the length), and then +s and -s to that. If a course has a bunch of +s and -s that even out, that doesn't mean the course rating is 100% the length. And what kind of math would it be if the course rating was lower than the formula: 103% length? 🙂 

[Carl3]

On 8/13/2025 at 9:56 PM, iacas said:

That's not the right way to look at it, because you're not going to have a rating of 55 or something for even a 6500-yard par 72. There's a minimum rating (depending on the length), and then +s and -s to that. If a course has a bunch of +s and -s that even out, that doesn't mean the course rating is 100% the length. And what kind of math would it be if the course rating was lower than the formula: 103% length? 🙂 

I was talking about the course rating, which is based on a scratch golfer and appears to be little affected by any of the obstacle calculations (less than 5%). The slope however is much more affected by the obstacles, which might have been what you were thinking of. The championship tees at Muirfield Village Golf Club, for instance appear to have 21% of the slope dictated by obstacles. The course rating of 75.3 however, appears to have the obstacles contribute about 3%. This makes sense as the rating is based on how far a scratch can carry a shot and slope has less of effect on the scratch golfer.

I got the info for calculating the Raw (scratch) rating and the Bogey Ray Rating from the Pope of Slope website. I am assuming that this is what is in the USGA Form 1 Excell spreadsheet:

"A "USGA Slope Rating" is determined by multiplying the difference between the Bogey Rating and the USGA Course Rating by 5.381. This constant will produce Slope Ratings of 113 when the differential between the Bogey Rating and Course Rating is 21.0 (The expected difference in score due to "bonus for excellence"). A Slope Rating of 113 also is the empirically derived average value on standard American golf courses.

The yardage rating equation for scratch men is length (yards) divided by 220 plus 40.9 (bx18). For bogey golfers the values are 160 and 50.7, respectively. Following are the obstacles factors considered by rating teams in determining the amount of adjustment of the Yardage Rating in arriving at the USGA Course and Bogey Rating along with the weighting factor applied to each obstacle value rated on a scale of 0 to 10."

Course Ratings

 

[Carl3]

The Pope of Slope Author is D. Knuth, who listed his title as the Director of Handicapping for the USGA. I do not believe that he currently is. He had a paragraph on his site (see above link) that I thought was interesting about future research on the "Player Variability Problem". HRT stands for the Handicap Research Team:

"The HRT has shown that 80% of all bogey golfers fit the model within one stroke. However, two distinct types of golfers fall outside of these limits. These types have been labeled "Steady Eddy" and "Wild Willy." Steady Eddy represents 12% of all golfers and he is a very straight, but short ball striker who has an outstanding short game. When taken from a short course to a long course, his score increase8 greater than the model would show, thus he is under-handicapped at a high Slope course. Conversely, Wild Willy is a long-hitter, but is inaccurate. Representing 8% of bogey golfers, this type can be over- handicapped on a long open course, but under-handicapped on any very tight and punitive course.

The HRT is considering a solution of adopting a normal model handicap formula which would mesh a two dimensional handicap to the Slope System. The solution could result in a Steady Eddy receiving more strokes on a high Slope Rated course than a Wild Willy of equal Handicap Index would receive."

So, do you fit into the 80% or are you a Steady Eddy or Wild Willy?🤣

Edited August 16 by Carl3