text: A handicap differential is calculated from each of the scores after Equitable Stroke Control (ESC), an adjustment which allows for a maximum number of strokes per hole based on the player's course handicap, has been applied using the following formula:
  The handicap differentials are rounded to one decimal place, and the best 10 from the last 20 submitted scores are then averaged, before being multiplied by 0.96 (the "bonus of excellence") and truncated to one decimal place to produce the handicap index. Initial handicaps are calculated from a minimum of five scores using ESC adjustments based on the course handicap corresponding to a handicap index of 36.4 for men or 40.4 for women. If there are at least 5 but fewer than 20 qualifying scores available, the handicap index is calculated using a set number or differentials according to how many scores are available.
  The basic formula for calculating the handicap index is as follows (where  is the number of differentials to use), with the result truncated to one decimal place:
  The handicap index is not used directly for playing purposes, but used to calculate a course handicap according to the slope rating of the set of tees being used. The result is rounded to the nearest whole number.
  Updates to a golfer's handicap index are issued periodically, generally once or twice per month depending on the local state and regional golf associations.