There is no doubt handicap systems differ from country to
country. The question is “How big are
those differences?” To examine this question,
the scoring records of six United States players were selected. Using these scores, an estimate of a
player’s Index was made for 5 of 6 major handicap systems—data limitations
prevented using the sixth system. The
term “Index” is used throughout even though it is peculiar to the United States
Golf Association (USGA) System. Index as
used here represents each system’s measurement of a player’s ability. The broad
outlines of each handicap system and the assumptions made in estimating the
player’s index are detailed below:
USGA
Handicap System – Both competitive and noncompetitive rounds are
allowed. Scores are not adjusted based
on playing conditions. A player’s
handicap differential is his gross adjusted score minus the course rating
multiplied by the ratio of 113/Slope Rating.
The maximum score a player can take on a hole is determined by his
handicap (e.g., a handicap between 10 and 19 is allowed to take a 7). A player’s Index is the average of his ten
best differentials multiplied by .96 and truncated to one decimal.
Council
of National Golf Unions (CONGU) – Only rounds made in competition are
used. The USGA’s Slope Rating system is
not used. Course Rating can be adjusted
based on the scores of players. For
various levels of Indices, a buffer zone is defined (e.g., 0 to 2 strokes above
the Course Rating). If a player’s net
score falls within the buffer zone, his Index is not changed. If his net score is above the buffer zone,
0.1 is added to his Index. If his net
score is below the Course Rating by nstrokes, his Index is reduced by n times
the adjustment factor for his Index level (e.g., the adjustment factor is 0.2
for players with an Index between 5.5 and 12.4).
In estimating a player’s CONGU
Index, the USGA Course Rating rounded to the nearest integer was used. It was assumed the rounds were played under
normal conditions so there was no adjustment to the Course Rating. A player’s CONGU Index was assumed to be his
USGA Index on the date of the oldest of his 20 scores. The player’s handicap was his CONGU Index
rounded to the nearest integer.
Starting with his oldest score, the player’s net score was calculated. If the net score triggered an adjustment, the
player’s Index was changed and a new handicap calculated. This procedure was used for all 20 scores.
Australia
– All rounds played under the Rules of Golf are used. Australia uses the USGA Course and Slope Rating
System but rounds the Course Rating to the nearest integer. The maximum score that can be taken on a hole
is a net double bogey. For handicap
purposes, a Daily Course Rating (DCR) is estimated. A player’s differential is based on his
Stableford score and is calculated as follows:
Course Par plus Handicap minus
(Stableford Points minus 36) = A
A minus the DCR = B
B multiplied by 113 = C
C
divided by the Slope Rating = D
D (rounded to one decimal place) = Differential
The Australian Index is based on
the average of a player’s 8 best differentials out of 20 multiplied by .93. It is assumed rounds were played
under normal conditions and differences in posted scores adjusted for stroke
control are minimal. Australia’s
differential calculation is approximately the same as in the USGA system. Therefore, the estimate of the Australian
Index was found by using USGA differentials, taking the average of the eight
best differentials, multiplying by .93, and truncating the result to the first
decimal.
South
Africa – All rounds played under the Rules of Golf are used. Currently, South Africa has not adopted the
Slope Rating system. The Course Rating
is expressed as an integer. Maximum
score on any hole is 2 over par except where a player has two handicap strokes
on a hole in which case the maximum score allowed is 3 over par for that hole. The differential is the player’s adjusted
gross score minus the Course Rating. A
player’s Index is the average of his 10 best differentials out of 20 multiplied
by .96. If a player has two exceptional
scores (i.e., a net score of 3 or more below the Course Rating), his Index is
based on his best eight scores.
In estimating the South African
Index, it was assumed the South African Course Rating was the USGA Course
Rating rounded to the nearest integer.
Differences in posted scores due to differences in stroke control were
assumed to be minimal.
Argentina
– Only scores from competitions are used.
Argentina has a Course Rating system loosely based on the USGA’s
system. There is no Slope Rating. There is no equitable stroke control. The handicap differential is the player’s
gross score minus the Course Rating. A
player’s Index is the average of a player’s 8 best scores out his last 16
scores multiplied .87.
In estimating the Argentina Index,
it is assumed the USGA Course Rating is equivalent to the Argentina Course
Rating. Differences due to different
stroke control procedures were assumed to be minimal.
European
Golf Association (EGA) – The EGA has adopted the USGA Course and Slope
Rating System. A player’s Index is
based primarily on rounds in competition.
A player’s handicap is his Index multiplied by 113/Slope Rating + Course
Rating – Par rounded to the nearest integer.
The Index adjustment process is similar to the CONGU system. A score below a player’s Stableford buffer
zone leads to a .1 increase in a player’s Index. A Stableford score npoints above the buffer
zone leads to a decrease of n times the adjustment factor for his Index level (e.g.,
.2 for a player with an Index between 4.5 and 11.4). Based on score in the competition the buffer
zone can be shifted up or down. Because par is not known and the
uncertainty in converting stroke play scores to Stableford scores, the player’s
EGA Index is not estimated.
The estimated Index for a selection of players is shown in
the Table below. The Australian Index is
usually the lowest since it is based on a player’s 8 best scores as opposed to
his 10 best in the USGA system. South
Africa is typically the highest Index since differentials are not adjusted by the
Slope Rating. If all scores were at a
course with a Slope Rating of 125, for example, the South African Index would
be approximately 11 percent higher than the USGA Index.
Table
Estimate of Player Index by Major Handicap
System
System

Player 1

Player 2

Player 3

Player 4

Player 5

Paler 6

USGA

7.3

12.9

9.9

4.4

6.4

19.0

CONGU

8.3

14.2

9.2

5.2

6.7

19.6

Australia

6.6

11.9

9.2

3.7

6.0

18.1

South Africa

8.5

14.7

11.8

4.8

7.2

20.5

Argentina

7.5

12.9

10.3

4.4

7.2

19.0

EGA

NA

NA

NA

NA

NA

NA

In general, the USGA Index is within ±1 of the Index in the
other systems. Such discrepancies, while
not negligible, do not create significant inequities. One remedy would be a Worldwide Handicap
System (WHS). But there are less expensive remedies available. Australians could have their Index increased
when playing in the United States. South
Africans playing in the United States would not be permitted to use the Slope
Rating to calculate their handicap since the Slope Rating was not used to calculate
their Index. These ad hoc solutions for what is social golf make more economic sense than
spending millions on a WHS to correct a rare and minor injustice.
Corrections to Australia:
ReplyDelete1. All rounds are eligible only if the club allows non competition roundsmost do not. Exceptions for rounds played with a member to ESTABLISH a hcp.
If a club did allow non competition rounds they would have to declared before starting and witnessed by a member.
2. Australia uses a daily course rating to determine the differential for that day. Formula includes field size, hcp, and scores.
The Daily Scratch Rating was mentioned in the post. I admit "all rounds" is not correct. It was my understanding clubs accepted conforming social scores. If clubs have different policies, then the handicap system is not administered uniformly which leads to problems in the portability of handicaps. Thanks for your comment.. ,
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