# Course Handicap & Slope Rating Explained

The purpose of this paper is to try and clarify the purpose of Slope Ratings / Course Handicaps, how they are supposed to work and stress that it is an essential part of the USGA Handicap System.

A *Handicap Index* is portable from course to course, as well as from one set of tees to another set of tees on the same course. A player converts a *Handicap Index* to a *Course Handicap* based on the *Slope Rating* of the tees played.

There are four key points:-

**Using the Course Handicap is not a PSC ‘rule’ it is an official USGA Handicap Rule which all member clubs are required to adhere to. Each club is required to provide their members with the Course Handicap and display their Course Handicap Table in their clubhouse.**

*(If you check the Notice Board at the desk in Green Valley (and I’m sure many others) you will find their official USGA Course Handicap Table)***Playing off a Handicap Index can be a definite advantage for the lower handicap players in competitions where they compete in the same flight.****The purpose of the Course Handicap is to negate any possible advantage in an attempt to create a level playing field for all handicaps.****It is the responsibility of every golfer to put their correct ‘Handicap’ on their score cards**.

Our web page calculates your entitled Course Handicap from every tee on every course in the system – just click the link Course Handicap. The PSC have also made a hard copy of the Course Handicap Tables available to every Society organizer in the Pattaya area.

#### Playing off Handicap Index v playing off Course Handicap

Broadly speaking on the preferred course / tees *(6200 yards)* we play in Pattaya, those in the 1 to 10 handicap range have a 1 shot advantage against some of those in the 11 to 20 range and 2 shots against some in the 21 to 27 range and 3 shots against some of those in the 28 to 33 range and 4 shots against those in 34 upwards.

The easier the course the less the advantage, the more difficult the course and the higher the handicap, the greater the advantage.

See the sample scores in Step 6 below to see the cause and effect). The ‘rounding up / rounding’ down is also factor in the calculations.

The rest of the golfing world *(excluding the UK and Ireland who use their own CONGU System)* use the USGA system although in some cases with slight authorised variations.

Many of you who have played golf in recent years in Australia or Europe, will know that, even on your home course, you do not play off your ‘Official Handicap’ – in Australia called your GA Handicap and in Europe your Exact Handicap – you play off what is called your Daily Handicap* (Aus)* and Playing Handicap* (EUR)* respectively. *(Equivalent of the USGA Course Handicap).*

### Why do we want to be different in Pattaya ?

#### History of USGA Course Rating System

The idea was first examined in the early 1980’s by the USGA who set up a special Handicap Research Committee *(consisting of twenty qualified golf administrators, graduate mathematicians and computer scientists)* to solve the problem that had existed since the 1920’s.

That problem was that there was no ‘standard’ method for measuring a player’s golfing ability.

Despite the existence of an accurate course rating at different courses *(Standard Scratch Score),* statistics showed that in matches between players from different courses, the average player from the more difficult course consistently won because handicaps based on one number *(the expected score of a scratch golfer)* do not transfer with higher handicap golfers to other courses across the board.

If Player A earned an 18 Handicap on an ‘average’ 6000 yard Course ‘X’ and Player B his 18 Handicap on a long difficult 7000 yard Course ‘Y’ :- **they are equal in handicap but not in golfing ability.**

After analysing between 10 and 12 million score cards from over 10,000 courses and a huge range of golfers the USGA Handicap Research Team developed a new concept of Course Rating based on a computer programmed formula of a ‘sample course’ as the new ‘standard’ and then using that formula as a template for grading all courses and golfers :-

*The formula used to calculate a Course Handicap takes into account the difficulty of the golf course using two numbers: the Course Rating and the Slope Rating. The former defines a level of difficulty for a ‘scratch’ golfer, while the latter describes how much harder the course will play for less skilful players of all handicaps.*

#### Step 1

The first part of a solution was to devise a ‘standard’, a ‘starting point’ or ‘index’ for every golfer based on a hypothetical course of ‘neutral’ or ‘average’ difficulty so that every golf handicap is starting from the same starting point – a ‘hypothetical neutral course’ and not each and every player’s differing home course.

The difficulty of a course is its Course *(or Scratch)* Rating and no matter how long or how difficult it is, the Scratch golfer will play to it when he plays to his handicap.

By ‘neutral’ we mean a course that because of its length and difficulty it is no more or no less difficult for a Scratch golfer than for a 21 handicapper *to play to their respective handicaps.*

The next part of the solution was to set a standard method for ‘measuring / rating’ all courses that would be equitable for all golfers of all levels.

The new ‘standard’ was a quite complex method of ‘course rating’ based largely on yardage *(hole yardage and hitting distance)* but now including the difficulties in the landing areas and around the green complex of each hole. *(And probably even more complex computer programmed calculations).*

This worked perfectly for a ‘rating’ based on a scratch golfers ability – a Scratch / Course Rating. Working correctly this means that no matter the course the scratch man should play to the Course Rating and is the ‘standard rating’ for the difficulty of every golf course. But the statistics showed very clearly that this did not apply to the less skillful golfers as the courses became more difficult.

#### Step 2

To understand how this should work we need to make performance comparisons for players of different handicaps. So lets return to our Players A and B from above and are now joined by Player C off scratch *(all now ‘USGA’ re-handicapped against a ‘neutral’ course similar to Course ‘X’)*

The best way to compare players performance is when players ‘play to their handicap’ on the same course and conditions.

**The USGA say that to play to your handicap your target score is – The Course Handicap plus the Course Rating. You will have played to your handicap when the resulting Handicap Differential is equal to or very close to your Handicap Index.** *(There may be slight variations because of rounding up or down in the Course Handicap calculation).*

On the ‘neutral’ Course ‘X’ – Based on their proven ability Player A would likely still be 18 but Player B would now likely be 15 and Player C would be ‘0’. If they play a ‘match’ on Course ‘X’ their handicaps are ‘fair’ *(Handicap Index / Course Handicap / Course Rating are the same),* if they ‘play to their respective handicaps’ by definition the contest will finish ‘All square’.

However, if they play a ‘match’ on the more difficult Course ‘Y’ then their ‘handicaps’ need to be adjusted to take into account the extra difficulty of this course – Player A would need 21 and Player B would likely need 18 but Player C would still be ‘0’ and if they all ‘play to their handicaps’ by definition the contest would end ‘All square’.

From this you can see that all their ‘handicaps’ had the same starting point* (Handicap Index based on ‘neutral’ Course ‘X’)* but when they move to the more difficult Course ‘Y’, Players ‘A’ and ‘B’ need an extra three shots each to enable them to ‘play to THEIR handicap’ but Player ‘C’ does not and remains the same on ‘0’.

These extra shots *(added to your Handicap Index)* are what we now call the Players Course Handicap!

This is the purpose of the ‘ Course Handicap’ and the USGA’s formal Definition is;-

A Course Handicap “…indicates the number of handicap strokes a player receives from a specific set of tees at the course being played to adjust the player’s scoring ability to the level of scratch or zero-handicap golf…”

### Step 3

If we use the data from Course ‘X’ info as the ‘hypothetical’ or ‘neutral’ course on which all handicaps are based and using the USGA specifications it would have a Yardage, Scratch and Course Rating of 68.

Again by ‘neutral’ we mean a course that because of its length and difficulty it is no more or no less difficult for a Scratch golfer than for a 21 handicapper to play to their respective handicaps.

Also a course is of ‘neutral difficult’ when the difference between the ‘scratch rating’ and the ‘bogey rating’ is 21, so our hypothetical Course ‘X’ would have a Scratch Rating of 68 and a Bogey Rating of 89 *(and a Slope Rating of 113)*

After more than ten years of research, data collection and field testing the Handicap Research Team produced a two parameter system and the USGA coined the term ‘bogey golfer’ for the average 21 handicapper and the concept of rating a course not just for the ‘Scratch Golfer’ but also for the ‘Bogey Golfer’ was born.

The official difficulty of a course is its Course *(or Scratch)* Rating and no matter how long or how difficult it is, the Scratch golfer will play to it when he plays to his handicap *(ability, on average).*

This is not true of non-scratch golfers and the statistics showed that the more difficult the course the higher their scores were, compared to their Handicap Index and thus ‘Slope Rating’ was invented and is the formula used to calculate the Course Handicap of a course for all non-scratch golfers by multiplying the players Handicap Index by the course Slope Rating and divided by the basic ‘neutral’ Slope of 113.

e.g Green Valley *(W)(Slope 125)* for a 21 Handicap Index is *(21×125÷113)*=23.2 rounded to 23. For a 10 Handicap Index it’s *(10×125÷113)*=11.1 rounded to 11.

Just to repeat, the absolutely essential key to the new USGA system was the concept to rate the difficulty of all courses for both a Scratch Golfer and a Bogey Golfer.

The Scratch number is ‘0’ and is fixed but the Bogey number is ‘indexed’ at 21 but needs to be recalibrated to find an average for every handicap between 1 and 36 *(m)* and 40 *(f)* and therefore they produced the required Course Handicap Table

#### Step 4

USGA Slope Rating, Course Rating & Course Handicap

Again to repeat :-

The formula used to calculate a Course Handicap takes into account the difficulty of the golf course using two numbers: the Course Rating and the Slope Rating. The former defines a level of difficulty for a ‘scratch’ golfer, while the latter describes how much harder the course will play for all less skillful players of all handicaps.

Slope Rating is not directly an assessment of the difficulty of the course *(or Tee)* itself but the extra degree of difficulty that course *(or Tee)* presents to a non-scratch golfer compared to the scratch golfer.

*(In our example above of the more difficult Course ‘Y’, the Course Rating would likely be 74 and the Bogey Rating would likely be 99, the difference would be 25 and therefore 25 multiplied by 5.381=a Slope Rating of 134 )*

So for now our above mentioned players play on the more difficult Course ‘Y’:-

Player ‘A’ would have a Course Handicap of 21 *(18 x 134÷113)* and Player ‘B’ a Course Handicap of 18 *(15 x 134÷113)* and Player ‘C’ still off ‘0’.

Using the math we can see that for Course ‘Y’ for other skill levels a 2 handicap will play off 2, a 4 handicap would play off 5, a 9 handicap off 11 and so on and the Course Handicap Table calculates for all handicaps.

We can now re-phrase the USGA Definition of Course Handicap slightly:-

*“…that indicates the number of handicap strokes a player receives from a specific set of tees at the course being played to adjust that player’s scoring ability to the level of the Course Rating of that course…”*

and is calculated by multiplying the players Handicap Index by the Course Rating and dividing by 113.

#### Step 5

Just a little more detail !

If we take a look at the Green Valley Ratings we know that off White Tees the Course Rating it is 70.1.

We also know that the Official GV* (W)* ‘Yardage Rating’ is 69.5 *(based on ‘yardage rating’ only)* but the Scratch Rating is 70.1 – this means that for a scratch golfer GV *(W)* has been rated 0.5 of a shot more difficult than the basic ‘neutral’ course. (on which his Handicap Index is based) – primarily because of the added ‘weighted’ difficulties in the area of the green complex.

We can work out that the ‘course raters’ gave GV *(W)* a Bogey Rating of approx. 93.3 and deducting 70.1 is 23.2 meaning it is 2.2 shots more difficult for the Bogey Golfer than the basic ‘neutral’ course (on which his Handicap Index is based). Therefore *(23.2 x 5.381)*=124.8 giving Green Valley *(W)* a Slope Rating of 125.

We know that the Official Course Rating for Green Valley *(Blue)* is 73.5.

We also know that GV *(B)* ‘Yardage Rating’ is 72.5 but as the Scratch Rating is 73.5, this means that GV (Blue) is rated 1 shot more difficult for the Scratch Golfer than the basic ‘neutral’ course.

We can again work out that the ‘course raters’ gave GV*(B)* a Bogey Rating of approx. 98.9 and deducting 73.5 we get 25.4 meaning it is 4.4 shots more difficult for the 21 handicapper than the basic ‘neutral’ course.Therefore 25.4 x 5.381=136.8 giving GV*(B)* a Slope Rating of 137.

#### Step 6

For some, these figures & calculations might be fairly meaningless – the usual quote is “I just want to play golf” (presumably off a fair handicap!) – using the concept of ‘playing to one’s handicap’ lets bring it into the reality of a few ‘friendly’ games on a Sunday morning on courses that we all know between our four players John, Paul, George and Ringo in:-

**Green Valley White***(70.1÷125)*- The players Handicap Indexes
*(Course Handicaps in brackets)*are John 4.0*(CH 4),*Paul 12.0*(CH 13),*George 19.0*(CH 21)*and Ringo 26.0*(CH29)* - John’s target gross score ‘to play to his handicap’ would be 74, Paul’s target gross 83, George’s target 91 and Ringo’s 99.
- John does not need any extra handicap shots to score net 70, Paul needs 1 extra shot to score net 70, George needs 2 extra and Ringo needs 3 extra if they are to ‘play to their handicaps’
- Now lets assume that they all play to their ‘handicap’ on the day so John’s gross score would be 74
*(net 70),*Paul score 83*(net 70),*George scores 91*(net 70)*and Ringo scores 99*(net 70)*so the game ends ‘All Square’.*(Net 70’s)* - But If they play off their Handicap Index John wins every time, his 74
*(net 70)*beats Paul’s 83*(net 71)*by 1 shot, George’s 91*(net 72)*by 2 and Ringo’s 99*(net 73)*by 3

- The players Handicap Indexes
**Silky Oak White***(68.3÷120)*- Now John’s Index is still 4.0
*(CH 4)*Paul 12.0*(CH13),*George 19.0*(CH 20)*and Ringo 26.0*(CH 28)* - John’s target gross score would be 72, Paul’s gross 81, George gross 88 and Ringo gross 96
- John does not need any extra handicap shots to score net 68, Paul needs 1 extra shot, George now needs only 1 extra and Ringo only 2 extra. Again lets say they all ‘play to their handicaps’ on the day so again the game ends ‘All square’ (Net 68’s)
- But if they play off their Handicap Index again John wins every time, his net 68 beats Paul’s net 69 by 1 shot, George’s net 69 by 1 and Ringo’s net 70 by 2

- Now John’s Index is still 4.0
**Green Valley Blue***(73.5÷137)*- John’s Index is 4.0
*(but now CH 5)*Paul 12.0*(CH 15)*George 19*(CH 23)*and Ringo 26*(CH 32)* - John’s target gross score is 79, Paul’s gross 89 George’s gross 97 and Ringo’s gross 106.
- Now John needs 1 extra shot to score net 74, Paul needs 3 extra , George needs 4 extra and Ringo 6 extra and again lets say they ‘play to their respective handicaps’ on the day and they would end up ‘All square’
*(Net 74’s).* - But If they play off their Handicap Index again John wins every time, his 79
*(Net 75)*beats Paul 89*(Net 77)*by 2 shots, George’s 97*(Net 78)*by 3 shots and Ringo’s 106 (Net 80) by 5 shots.

- John’s Index is 4.0

The USGA say that the only time a player plays off a Handicap Index type number is when the Slope Rating of the course is 113. If it is higher he will likely gain handicap shots and if its less he will likely to lose handicap shots.

Playing off a Course Handicap only affects the competition on the day eg if you play GV* (W)* with* (Handicap Index 21.0)* Course Handicap 23 and score 38 points that would be 36 points off your Handicap Index 21 and could often be the difference between winning and losing!

It is also worth pointing out that in a Stableford competition whether you play off a Handicap Index or Course Handicap does NOT affect your subsequent handicap calculation for that round as the Adjusted Gross Score will be the same 93.

#### Overview – Key points

- This is not a PSC ‘rule’ it is an official USGA Handicap Rule which all member clubs are required to adhere to.
- That playing off a Handicap Index can be a definite advantage for the lower handicap players in competitions where they compete in the same flight.
- The purpose of the Course Handicap is to negate any possible advantage in an attempt to create a level playing field for all handicaps.
- It is the responsibility of every golfer to put his/her correct ‘Handicap’ on their score cards.

E&OE accepted.