A handicap is calculated with a specific arithmetic formula that approximates how many strokes above or below par a player might be able to play.
A golfer’s net score is determined by subtracting the player’s handicap from the gross score (the number of strokes actually taken). The net scores of all the competing golfers are compared and (generally) the person with the lowest score wins.
A player’s handicap is intended to show a player’s potential, not his average score, as is the common belief. The frequency by which a player will play to their handicap is a function of that golfer’s handicap, as low handicappers are statistically more consistent than higher handicappers. The USGA refers to this as the “average best” method. So in a large, handicapped competition, the golfer who shoots the best with respect to his abilities and the normal variations of the score should win.
While there are many variations in detail, handicap systems are generally based on calculating an individual player’s playing ability from his recent history of rounds. Therefore, a handicap is not fixed but is regularly adjusted to increases or decreases in a player’s scoring.
In the United States, handicaps are calculated using several variables: The player’s scores from his most recent rounds, and the course rating and slope from those rounds. A “handicap differential” is calculated from the scores, using the course slope and rating, and the player’s handicap differentials are used to calculate the player’s handicap.
Scratch and bogey golfers
A golfer whose handicap is zero is called a “scratch golfer.” A golfer whose handicap is approximately 18 is called a “bogey golfer.” It is possible to have a handicap below 0; these are referred to as ‘plus’ handicaps, and at the end of the round, a ‘plus’ handicap golfer must add his handicap to his score. If his handicap is a minus number, like -15, then adding that number to the number of total strokes will actually reduce that golfer’s final score. If a player shoots a 100 and has a minus 15 handicap, his final score will be 85.
Course rating and slope
In the United States each officially rated golf course is described by two numbers, the course rating and the slope rating. The course rating of a particular course is a number generally between 67 and 77 that is used to measure the average “good score” by a scratch golfer on that course. The slope rating of a particular course is a number between 55 and 155 that describes the relative difficulty of a course for a bogey golfer (defined above) compared to a scratch golfer. These two numbers are used to calculate a player’s handicap differential, which is used to adjust a player’s score in relation to par according to the slope and rating of the course. The slope rating for a golf course of average difficulty is 113.
For each officially posted round, the player’s handicap differential is calculated according to the following formula:
The handicap index is then calculated using the average of the best 10 differentials of the player’s past 20 total rounds, multiplied by 0.96. Any digits in the handicap index after the tenths are truncated. If a golfer has at least 5 but fewer than 20 rounds posted, the index is calculated using from one to nine differentials according to the following schedule:
The differential is rounded to the nearest tenth.
Number of rounds → Differentials to use
5 or 6 → lowest 1
7 or 8 → lowest 2
9 or 10 → lowest 3
11 or 12 → lowest 4
13 or 14 → lowest 5
15 or 16 → lowest 6
17 → lowest 7
18 → lowest 8
19 → lowest 9
Updates to a golfer’s index are calculated periodically according to schedules provided by state and regional golf associations.
The handicap index is used with the course’s slope rating to determine the golfer’s course handicap according to the following formula:
The course rating is not used to determine a course handicap. The result is rounded to the nearest whole number.
The course handicap is the number of strokes to be deducted from the golfer’s gross score to determine the net score.
For example, the following table shows the impact of the same score at two different tee positions at the same course, and the resulting handicap differential:
Gross score: 85
Course rating: 69.3
Course slope: 117
Yields a handicap differential of 15.2. If this golfer’s handicap index is 10.5, the course handicap would be and the net score would be 85 − 11 = 74.
Gross score: 85
Course rating: 71.9
Course slope: 124
Yields a handicap differential of 11.9. If this golfer’s handicap index is 10.5, the course handicap would be and the net score would be 85 − 12 = 73.
Additionally, before making the above calculation, the gross score must be adjusted using the equitable score control table, which removes the effect of abnormally high individual hole scores by establishing a maximum score per hole depending on the player’s handicap index. For example, a golfer with a course handicap of 20 through 29 can record a maximum of 8 strokes on any one hole for handicap calculation purposes only.
Calculating a score
The handicap is used to determine on which holes a player (or team) is granted extra strokes. These are then used to calculate a “net” score from the number of strokes actually played (“gross” score).
To find how many strokes a player is given, the procedures differ between match play and stroke play. In match play, the difference between the players’ (or teams’) handicaps is distributed among the holes to be played. For example, if 18 holes are played, player A’s handicap is 24, and player B’s handicap is 14, then A is granted ten strokes: one on each of the ten holes identified by the handicap numbers 1 through 10 on the scorecard and no strokes on the remaining eight. If A’s handicap is 36 and B’s handicap is 14, A is granted 22 strokes: one on each of the 18 holes to be played, and an additional one on each of the four holes identified by the handicap numbers 1 through 4 on the scorecard.
The procedure in stroke play is similar, but each player’s individual handicap (rather than the difference between two players’ handicaps) is used to calculate extra strokes. Therefore, a player with handicap 10 is granted one stroke on each of the ten holes identified by the handicap numbers 1 through 10 on the scorecard and no extra strokes on the remaining eight. A player with a handicap of 22 is granted 22 strokes: one on each of the 18 holes and an additional one on each of the four holes identified by the handicap numbers 1 through 4 on the scorecard.
Example for the calculation of “net” results: Assume that A is granted one stroke on a par four hole and player B is granted none. If A plays six strokes and B plays five, their “net” scores are equal. Therefore, in match play the hole is halved; in stroke play both have played a “net” bogey (one over par). If both play five strokes, A has played better by one “net” stroke. Therefore, in match play A wins the hole; in stroke play A has played a “net” par and B a “net” bogey.
Andy → 14.8
Bob → 9.9
Chris → 1.5
Dan → 26.4
Let’s say that we have four golfers: Andy, Bob, Chris, and Dan, of various abilities who are in a competition against each other. To the right are the players and their handicap indices. The course (from the tees being played) has the following slope: 120.
Name → Calc. → Real → Rounded
Andy → (120/113) * 14.8 → 15.72 → 16
Bob → (120/113) * 9.9 → 10.51 → 11
Chris → (120/113) * 1.5 → 1.59 → 2
Dan →(120/113) * 26.4 → 28.04 →28
So, using the formulas above, here are their course handicaps from the tees being played (note that only the slope is used to determine the handicap):
Name → Gross → Net
Andy → 91 → 91 – 16 = 75
Bob → 86 → 86 – 11 = 75
Chris → 74 → 74 – 2 = 72
Dan → 99 → 99 – 28 = 71
And, finally, to the right are their gross and their net scores. Dan wins because he is the only one in the group who actually shot better than his handicap.
The slope rating is the USGA mark that indicates the measurement of the relative difficulty for a bogey golfer compared to the course rating. Slope rating is computed from the difference between the bogey rating and the course rating. The lowest slope rating is 55 and the highest is 155. The average slope rating is 113. To compute the handicap strokes from a given set of tees on a specific course with a slope of “s” given a handicap index of “h,” the following formula is used: (s/113)*h rounded to the nearest integer.
Example: A male golfer plays a course with Slope Rating 126, and Course Rating 72.5. Per the formula, compute 126 / 5.381 + 72.5 = 95.9 – which predicts the bogey golfer’s average of his ten best (out of twenty) scores would be approximately 95.9 from this particular set of tees.
History of the USGA system
The USGA has often resorted to the courts to protect the integrity of its handicap system. In one such case, the California Court of Appeal (First District) summarized the system’s history:
The USGA was founded in 1894. One of its chief contributions to the game of golf in the United States has been its development and maintenance since 1911 of the USGA handicap system . . . designed to enable individual golf players of different abilities to compete fairly with one another. Because permitting individual golfers to issue their own handicaps to themselves would inevitably lead to inequities and abuse, the peer review provided by authorized golf clubs and associations has always been an essential part of the [system]. Therefore, in order to protect the integrity and credibility of its [handicap system], the USGA has consistently followed a policy of only permitting authorized golf associations and clubs to issue USGA handicaps . . . . In 1979, USGA assembled a handicap research team to investigate widespread criticisms of USGA’s then-existing handicap formula. The research team invested approximately a decade and up to $2 million conducting intensive analysis and evaluation of the various factors involved in developing a more accurate and satisfactory [system]. As a result, the research team developed new handicap formulas . . . designed to measure the overall difficulty of golf courses, compare individual golfers with other golfers of all abilities, take account of differences between tournament and casual play, and adjust aberrant scores on individual holes. USGA subsequently adopted and implemented these new formulas between 1987 and 1993.