FORMULAS Section 10 USGA HANDICAP FORMULA A Handicap Index is the USGA's mark which is used to indicate a measurement of a player's potential scoring ability on a course of standard difficulty. Potential scoring ability is measured by a player's best scores, and is expressed as a number taken to one decimal place. These scores are identified by calculating the handicap differential for each score. The USGA Handicap Index is calculated by taking 96 percent of the average of the best handicap differentials, and applying Section 10-3 for golfers with two or more eligible tournament scores. 10-1. How to Determine Handicap Differentials A handicap differential is computed from four elements: 1. Adjusted Gross Score 2. USGA Course Rating 3. USGA Slope Rating 4. 113 (the Slope Rating of a course of standard difficulty). To determine the Handicap Differential, subtract the USGA Course Rating from the adjusted gross score; multiply the difference by 113; then divide the resulting number by the USGA Slope Rating. Round the final number to the nearest tenth. Handicap Differential = (Adjusted Gross Score - USGA Course Rating) x 113 / USGA Slope Rating A. Example of a Plus Handicap Differential When the adjusted gross score is higher than the USGA Course Rating, the handicap differential is a positive number. Following is an example for determining a differential using an adjusted gross score of 95 made on a course with a USGA Course Rating of 71.5 and a USGA Slope Rating of 125: Adjusted Gross Score USGA Course Rating: 95-71.5 = 23.5 Difference x Standard Slope: 23.5 x 113 = 2655.5 Result / USGA Slope Rating: 2655.5 / 125 = 21.244 Handicap Differential (rounded): 21.2 B. Example of a Minus Handicap Differential (not a factor in this league) When the adjusted gross score is lower than the USGA Course Rating, the handicap differential is a negative number. Following is an example for determining a differential using an adjusted gross score of 69 made on a course with a USGA Course Rating of 71.5 and a USGA Slope Rating of 125: Adjusted Gross Score - USGA Course Rating: 69-71.5 = -2.5 Difference x Standard Slope: -2.5 x 113 = -282.5 Result / USGA Slope Rating: -282.5 / 125 = -2.26 Handicap Differential (rounded): -2.3
10-2. USGA Handicap Index Formula The USGA Handicap Index Formula is based on the best handicap differentials in a player's scoring record. If a player's scoring record contains 20 or more scores, then the best 10 handicap differentials of the most recent 20 scores are used to calculate his USGA Handicap Index. The percentage of scores used in a scoring record decreases from the maximum of the best 50 percent as the number of scores in the scoring record decreases. If the scoring record contains 9 or 10 scores, then only the best three scores (30 to 33 percent) in the scoring record will be used. Thus, the accuracy of a player's Handicap Index is directly proportional to the number of acceptable scores he has posted. A USGA Handicap Index shall not be issued to a player who has returned fewer than five acceptable scores. The following procedure illustrates how authorized golf associations and golf clubs calculate a player's Handicap Index if the number of acceptable scores in the player's record is fewer than 20. The procedure for calculating Handicap Indexes is as follows: Use the following table to determine the number of handicap differentials to use; Number of Acceptable Scores Differentials To Be Used 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 20 Lowest 10 (1) Determine handicap differentials; (2) Average the handicap differentials being used; (3) Multiply the average by.96; * (4) Delete all numbers after the tenths digit. Do not round off to the nearest tenth. Example 1: League uses your last 11 scores. Total of lowest 4 handicap differentials: 103.5 Average (103.5 divided by 4): 25.875 Multiply average by.96: 24.84 Delete digits after tenths: 24.8 USGA Handicap Index: 24.8 *Note: Bonus for Excellence is the incentive that is built into the USGA Handicap System, for players to improve their golf games. It is the term used to describe the small percentage below perfect equity that is used to calculate Handicap Indexes (96%). As your Handicap Index improves (gets lower), you have a slightly better chance of placing high or winning a handicap event.
Example 2: The following is a sample scoring record of a player with 20 scores that shows how his USGA Handicap Index is calculated by a golf club or authorized golf association prior to applying Section 10-3. Date USGA USGA Slope Handicap Adjusted Course Rating Differential Score Rating 3/21/97 90 70.1 116 19.4 3/12/97 91 70.1 116 20.4 2/24/97 94 72.3 123 19.9 2/20/97 *88 70.1 116 17.4 1/18/97 89 70.1 116 18.4 1/17/97 *90 72.3 123 16.3 1/16/97 *91 72.3 123 17.2 12/12/96 91 70.1 116 20.4 12/10/96 91 70.1 116 20.4 11/8/96 86 68.7 105 18.6 11/4/96 90 70.1 116 19.4 11/1/96 *92 72.3 123 18.1 10/24/96 *85 68.0 107 18.0 10/16/96 *78 68.7 105 10.0 10/12/96 *82 70.1 116 11.6 10/2/96 *84 70.1 116 13.5 9/14/96 94 72.3 123 19.9 9/5/96 93 72.3 123 19.0 9/4/96 *89 72.3 123 15.3 9/1/96 *88 70.1 116 17.4 Total of 10 lowest differentials: 154.8 Average (154.8 divided by 10): 15.48 Multiply average by.96: 14.861 Delete all digits after tenths: 14.8 USGA Handicap Index: 14.8 Apply Section 10-3 for golfers with two or more eligible tournament scores. 10-4. Course Handicap A player's Course Handicap is determined by multiplying his USGA Handicap Index by the USGA Slope Rating of the course played and then dividing by 113. The resulting figure is rounded off to the nearest whole number (.5 or more is rounded upward). Optionally, Course Handicaps may be printed on handicap records and cards.
10-5. Nine-Hole Handicaps - Handicap Index (N) a. Nine-Hole Handicap Use and Identification A nine-hole handicap is an official USGA Handicap Index provided the club follows the USGA Handicap System. A nine-hole handicap may be used in inter-club play against other players with nine-hole handicaps. A player with a Handicap Index and a Handicap Index (N) should use his Handicap Index (N) in inter-club nine-hole competition. If an 18-hole competition requires Handicap Indexes, Handicap Index (N) may be doubled. If a player with a Handicap Index plays in a nine-hole competition, he halves his Handicap Index and rounds the hundredth decimal to the nearest tenth and then enters the Course Handicap Table. b. Method of Computation Golf clubs compute Handicap Indexes (N) by applying nine-hole adjusted gross scores to the Course and Slope Ratings of the nine holes played to determine handicap differentials. For example, for an adjusted gross nine-hole score of 45 with a nine-hole Course Rating of 36.2 and a Slope Rating of 121, the nine-hole handicap differential is (45-36.2) x 113 / 121 = 8.2. If the average of the best ten nine-hole handicap differentials is 8.9, then the Handicap Index (N) is 8.9 x.96 = 8.5. It is written as "8.5N". c. Nine-Hole Equitable Stroke Control Equitable Stroke Control (ESC) is the downward adjustment of individual hole scores for handicap purposes in order to make handicaps more representative of a player's potential scoring ability. ESC sets a maximum number that a player can post on any hole depending on the player's Course Handicap. ESC is used only when a player's actual or most likely score exceeds his maximum number based on the table below. There is no limit to the number of holes on which a player may adjust his score. EQUITABLE STROKE CONTROL Nine-Hole Course Handicap Maximum Number On Any Hole 4 or less Double Bogey 5 through 9 7 10 through 14 8 15 through 19 9 20 or more 10 Example: A player with a nine-hole Course Handicap of 12 must adjust to a maximum number of 8, the score that he can post for any hole, regardless of par. d. Maximum Nine-Hole Handicap The maximum USGA Handicap Index (N) is 18.2 for men and 20.2 for women. Note: A maximum USGA Handicap Index (N) will convert to a Course Handicap that exceeds these numbers on golf courses with Slope Ratings greater than 113. A player may have a local handicap above these limits, but it shall be identified as a local handicap by the letter "J" following the number on a handicap card or report. (e.g. 24.5J) When such local handicaps are used for inter-club play, the USGA recommends that they be reduced to the maximum USGA Handicap Indexes (N) specified above.
League Handicap Summary: 1. We take your score for the night and calculate your Adjusted Gross Score using the Equitable Stroke Control schedule in Section 10-5. Example: If you are a 10 handicap, your maximum score on a hole that goes towards you handicap is an 8. So if you shot a 50 and had a 9 on a hole, your Adjusted Gross Score is 49. 2. Next we calculate your Handicap Differential for this round. (Note: example based on white tees) Example: (49-35.05) x 113 / 123 = 12.8158 Your Handicap Differential for this round is 12.8 3. The league analyzes your last eleven rounds and uses you best 4 rounds based on their Handicap Differential. We take the average of these 4 rounds and multiplies it by.96. Example: Your best 4 rounds had Differentials of 12.8, 12.0, 11.8, 10.0. (46.6 / 4) x.96 = 11.184 Your new handicap would be: 11 Please remember if you do not have an established handicap then the first four rounds are generated by the league officers and we do the best we can. Once you get your 5 th round in you enter the above handicap system. There will definitely be some fluctuation in your handicap based on the number of rounds accepted. It will level out once you get your eleven rounds in.