# United States Golfing Association Handicap System

 Indroduction For the purposes of the Happy Hackers Golf Society, the USGA estimated handicap that is generated for each member is a very simplified a rough estimate of what each member could expect to be playing at. For a detailed description of what the USGA Handicap system is please refer to the Official USAG Handicap System Manual.

DESCRIPTION
The calculation of a USGA Handicap in it's simplified form is as follows:

Firstly you look at the all the previous rounds entered for a specified golfer, if more than 20 rounds entered then the most recent 20 rounds are examined.

The Handicap Differential for each of these rounds is calculated, and from the following table the specified number of best rounds are extracted :

 Rounds Played Rounds Used 1-6 1 7-8 2 9-10 3 11-12 4 13-14 5 15-16 6 17 7 18 8 19 9 20 10

To Calculate the a rounds Handicap Differential the following formula is used :

((Adjusted Gross Score - USGA Course Rating) / 113) * USGA Slope Rating

The above formula translates to the following in our terms :

• Adjusted Gross Score = Number Of Strokes Taken to complete 18 Holes
• USGA Course Rating = Standard Scratch Score for this course
• 113 = Default Slope Rating for a course
• USGA Slope Rating = Actual Slope (Difficulty) rating for a course as specified by USGA.

The USGA Slope Rating is only available on courses in the US. So for the purposes of the Happy Hackers, every course has a rating of 113. Not entirely accurate, but there's really nothing else that can be done.

Once a specific number of lowest rounds has been calculated an average Handicap Differential is determined and multiplied by 0.96 to get your USGA Handicap :

(Accumulated Handicap Differential / No Of Rounds) * 0.96

An Example
Take Golfer A, who has played the following rounds of Golf :

 Round Strokes (Adj. Gross Score) Standard Scratch Slope Rating Hcap Differential 1 110 71 113 ((110-71/113))*113 = 39 2 103 72 113 ((103-72/113))*113 = 31 3 88 69 113 ((88-69/113))*113 = 19 4 94 72 113 ((94-72/113))*113 = 22 5 95 71 113 ((95-71/113))*113 = 24 6 100 71 113 ((100-71/113))*113 = 29 7 92 70 113 ((92-70/113))*113 = 22 8 94 71 113 ((94-71/113))*113 = 23 9 105 71 113 ((105-71/113))*113 = 34 10 102 69 113 ((102-69/113))*113 = 33 11 104 72 113 ((104-72/113))*113 = 32 12 102 72 113 ((102-72/113))*113 = 30 13 107 72 113 ((107-72/113))*113 = 35 14 102 72 113 ((107-72/113))*113 = 30 15 94 72 113 ((94-72/113))*113 = 22 16 109 69 113 ((109-69/113))*113 = 40 17 104 72 113 ((104-72/113))*113 = 32

As 17 Rounds have been entered, we take the best 7 Handicap Differentials :

 Round Hcap Differential 3 19 4 22 5 24 6 29 7 22 8 23 15 22

From the above listed lowest rounds :

• Accumuluated Handicap Differential = 161
• No Of ROunds Used = 7
• USGA Handicap = (Accumulated Handicap Differential / No Of Rounds) * 0.96
(161 / 7) * 0.96 = 22.08
Rounded USGA Handicap = 22.1

I hope this example explains how the Happy Hackers Society members estimated USGA handicap is calculated.