Monday, January 25, 2021

World Handicap System's Stroke Allocation Method: Part I

 

The World Handicap System (WHS) proscribes a new method for determining how handicap strokes are allocated among holes.  Appendix E of the Rules of Golf states that each hole should be ranked by playing difficulty.  Hole difficulty is defined by:

              Hole Difficulty = Stroke Value + Bogey Value – 2 x Par

The Rules of Golf, however, does not define Stroke or Bogey Values or give any indication on how they are to be estimated.  It does say these values “can be determined objectively using hole-by-hole data from the Course Rating Procedure”.  Part II will examine if this assertion has any validity. 

The WHS removes the stroke allocation analysis from the club’s handicap committee and places it with the regional golf association (i.e., from those to regularly play the course to those who walk the course once every five years.  Part I examines the work of the Southern California Golf Association (SCGA) as a test of whether the switch to a regional association made for any improvement in the allocation process.  The SCGA prepared a Stroke Index Progression Report (5/18/2020) for two courses.[i]  The errors and inconsistencies in the report indicate removing the analysis from the handicap committee was problematical.  The troubling difficulties with the report are detailed below:

1. Mistake in Assigning Hole Difficulty - As shown in Table 1, the SCGA assigned different difficulties to the exact same tees.  For example, on hole 1 of Course 1 the tournament tees are the black tees, yet the Report shows different difficulties.  These errors do not affect the results but do indicate a lack of care in preparing the report.  A handicap committee would be familiar with the course and not make such a basic error.

Table 1

Hole Difficulty Errors 

Course

Hole

Tee

Difficulty

Tee

Difficulty

Course 1

1

Black

1.28

Tournament

1.24

Course 1

18

Tournament

0.77

White

0.80

Course 2

1

Black

1.53

Tournament

1.50

Course 2

2

Black

0.51

Tournament

0.41*

Course 2

18

Black

1.68

Tournament

1.64

 

* The difficulty was .51 on the Tournament Tee rating but was entered as .41 on the summary sheet.

 

2. The Weighted Hole Difficulties Are in Error - The report only shows the hole difficulty for four sets of tees.  When the hole difficulties are weighted by the number of rounds played, the results for the Course 2 differ from those shown in the report.  Table 2 below gives an example for hole 3 on the Course 2.

Table 2

Weighted Hole Difficulty 

Tee

Report Difficulty(D)

Number of Rounds(R)

Weighted Avg. D*R/8934

Black

0.48

1146

.06

Tournament

0.48

2838

.15

White

0.48

3549

.19

Green

0.27

1401

.04

 

 

Weighted Difficulty

.44

 

The weighted average is .44 and not .32 shown in the report.  Since the weighted hole difficulties for the Course 1 are correct, there must have been computational errors in the Course 2 calculations.  Why did not the SCGA double check its calculations?  Probably because it has to turn out hundreds of such reports and knew the recipient clubs would not the report’s accuracy.   It is doubtful that handicap committees concerned with only one course would be so cavalier, but that remains to be tested.

3. Inconsistencies in Course Rating Estimates - The sum of the Scratch Values should equal the Course Rating.  The sum of the Bogey Values should equal the Bogey Rating.  Then an equation for the Course Rating would be:

 

Eq. 1   Course Rating = ((2 x Par) + HD - Slope Rating/5.381)/2

Where,

                             HD = Hole Difficulty summed over all holes

The report provided hole difficulty for two courses with four sets of tees.  Table 3 shows the Course Rating as calculated by Eq. 1 and the SCGA Course Rating.

Table 3

Course Ratings

 

Course

Rating

Course 1

Black

Course 1

Tourn.

Course 1

White

Course 1

 Green

Course 2

Black

Course 2

Tourn.

Course 2

White

Course 2

 Green

Eq. 1

71.6

70.3

69.3

67.5

71.5

70.4

68.5

65.8

SCGA

71.0

69.6

68.7

66.9

71.2

70.0

68.4

65.7

Difference

0.6

.07

0.6

0.6

0.3

.04

0.1

0.1

 

Eq. 1 always overestimates the SCGA Course Rating.  The difference in Course Ratings at Course 2 could be due to rounding errors.  The differences at Course are too large to be explained by rounding.  The hole difficulties would have to be reduced by 1.2 strokes to eliminate the difference.  The inconsistencies in Course Ratings between the two methods may indicate Course Ratings are not the sum of hole ratings. If that is the case, the accuracy of the Scratch and Bogey Values are brought into question.

4. Incorrect Distance Measurements – The SCGA has rated the courses based on the yardages shown on the card.  Many of those yardages are in error due to the way the courses are setup.  The most egregious example is hole 5 of the Course 2.  The green tees are set alongside the red tees and not the white tees as specified on the card.   The misplacement of tees leads to errors in both the Course Ratings and anomalies in the stroke allocation (e.g., the relatively benign Hole 5 on the Course 2 is rated more difficult than Hole 2 where a hard green is surrounded by sand and water).   A handicap committee would be aware of the course set-up and would not make the same mistake.   

 

Conclusions on the efficacy of the WHS’s method cannot be drawn from a single example.  The example does support the contention Handicap Committees are better suited to doing the stroke allocation analysis because of their familiarity with the course and a greater sense of responsibility to doing it right.  It is likely, however, the analysis will remain in the hands of golf associations.  The WHS recommended method relieves the handicap committee from the arduous task of collecting scorecards and analyzing hole-by-hole scores.  Many committees will adopt this easier road believing the regional golf association cannot be wrong and if there is the blame it will be placed on the association and not us.   Part II will examine the accuracy of the WHS method and determine if there is another reason not to cede control of the stroke allocation process to the regional association.     



[i] Stroke Index is a new term introduced in the WHS.  Formerly, the USGA simply referenced the “The Allocation of Handicap Strokes.”  Other golf associations (Golf Australia and the Council of National Golf Unions) did use the term “Stroke Index.”  However, the Stroke Index is not an index.   Its use is both wrong and confusing with the more prominent Handicap Index. 

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