Players are awarded a Handicap Index based on the average of the best 8 rounds from their last 20 games. The official description is the average of the best 8 Score Differentials from the last 20 acceptable scores.

The Course Handicap is the Handicap Index adjusted by slope rating. For example, the course rating is 121 for the yellow tee course for both men & women. The adjustment is 121 divided by 113 equalling 1.07. So for a Handicap index of 15 the Course Handicap is 16.06 rounded to 16. This is further adjusted by the handicap allowance for the competition format.

The Course Rating an indication of difficulty of a golf course for a scratch golfer under normal course and weather conditions. For the yellow course this is 64.2 for men and 68 for women.

Adjusted Gross Score is a way to adjust a player’s score to compensate for disastrous holes. Scores at such holes are reduced to net double bogey. There is no change from the old system.

Score Differential is the adjusted gross score less the course rating, adjusted where necessary by an allowance for playing conditions (Playing Conditions Calculation) times 113 divided by the course slope (121). A male player playing with a Playing Handicap of 15 on the yellow course with an adjusted gross score of 85 would have a score differential of 85 – 64.2 x 113/121 minus PCC =  20.8 x 0.933 = 19.4. This value is rounded to one decimal place.

Playing Handicap is the actual number of strokes a player gives or receives for the round being played. So for our player with a handicap index of 15 playing a medal round on the yellow course will receive 95% of their course handicap of 16 which is 15.2 giving a playing handicap of 15.

Playing Conditions Calculation (PCC) is an adjustment to reflect how harder or easier the course played on the day of a competition. Values of -1, 0, 1, 2, & 3 are applied in the calculation of score differentials. It is arrived at by
Calculating the expected score for each player

• Calculating the standard deviation of the expected score differentials
• How many players scored better or worse than expected
• The proportion of players who scored better or worse than the expected scoring range.

Exceptional Scores are defined where a player returns a score where the score differential exceeds 7. For score differentials between 7.0 & 9.9 the handicap index is reduced by 1 and is applied to all 20 recorded scores.  Similarly, for score differentials of 10 or more the reduction is 2.

Observations The new handicapping is complicated. It becomes more complicated when it rightly caters for new golfers, golfers with less than 20 acceptable scores of 9 hole rounds.  One feature of note is that a player’s handicap index will alter significantly when a great round drops out of the 20 scores record.

The R&A Guide to Handicapping

The Scottish Golf Guide to Handicapping