The USGA Handicap System

This handicap system calculates a players handicap using the course rating and slope rating.
( Note - At GolfSoc.com you can choose to use just the course rating, in which case the slope rating is always set to the average slope rating of 113 )

Handicaps are worked out by calculating handicap differentials :-

Handicap Differential = (Total Adjusted Gross Score For The Round - Course Rating) x (113 / Slope Rating)

The adjusted gross round score is calculated based on current handicap as follows:-

Current Handicap (rounded)	Maximum Score Per Hole
0-9	Double Bogey
10-19	7
20-29	8
30-39	9
40 or more	10

Handicap differentials are calculated for a players last 20 rounds (or all available rounds if less than 20), then the lowest differentials are used to calculate the handicap.

The number of differentials used depends on the number of rounds available as follows:-

Number of Rounds Available	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

The average of the handicap differentials is then taken and multiplied by 0.96 to give a final figure.
This figure is then trucated to 1 decimal point (not rounded), to give the players handicap.