Prestwick Country Club used the "Allocation Based on Scores" method describing in section 17-2 of the USGA Handicaps Manual

17-2. Allocation Based on Scores

A mathematical method for allocating strokes, based on the principle that a handicap stroke should be an equalizer when an average or high-handicapped player plays a low-handicapped player, follows. This procedure may be applied separately with men's scores and women's scores.

Note: When using all score methods, the Handicap Committee must give priority to the considerations of 17-1. See step (vii) below.

a. Comparison Method

(i) Collect about 200 hole-by-hole scores of a group of players (Group A) with a Course Handicap not exceeding 8 strokes for men and 14 strokes for women. A club having a limited number of low-handicapped players may use 200 scores from 25 percent of its players with the lowest Course Handicap. These scores should not be adjusted by Equitable Stroke Control.

(ii) Average the score for each hole for Group A, and average the Course Handicap of the players in Group A.

(iii) Collect about 200 hole-by-hole scores of a middle- to high-handicapped group of players (Group B). The average of the Course Handicap of each player in Group B should be 15 to 20 strokes higher than the average for each player in Group A. It is preferable for the Course Handicap of each player in Group B to range from 20 to 28 strokes for men and from 26 to 40 strokes for women. These scores should not be adjusted by Equitable Stroke Control.

(iv) Average the score for each hole for Group B and average the Course Handicap of the players in Group B.

(v) Determine the difference in the average scores for each group on each hole by subtracting the average score of Group A from the average score of Group B.

(vi) List the holes in order from 1 through 18 with corresponding Group A average scores, Group B average scores and average score difference. Rank the holes with the hole having the highest average score difference first, and so on. The hole ranked number 1 is the hole on which the higher-handicapped player most needs a stroke. Continue the rankings through 18.

(vii) Modify the rankings of the holes, as based on average-score differences in accordance with Section 17-1b on distribution of strokes, and in accordance with Notes 1 and 2 below.

Note 1: Occasionally, this method will result in one hole (Hole A) ranked ahead of another hole (Hole B). The committee believes that Hole B should be ranked ahead of Hole A. The committee may first determine the average range by subtracting the average-score difference of the 18th ranked hole from the average-score difference of the first ranked hole and divide the result by 18. If the difference between the average-score differences of Holes A and B is no greater than the average range, it would be appropriate for the committee to rank Hole B ahead of Hole A.

Note 2: A hole with a water hazard that presents a significant problem for high-handicapped players may be ranked as the first or second handicap-stroke hole based on its average-score difference. The committee believes that this ranking is not justified when players of comparable ability are competing. In this instance, the committee may downgrade the ranking of the hole. The committee should always use good judgment in deciding what will give fair results.

b. Regression Method

An alternative method of allocating handicap strokes which uses all data points is to use linear regression. A minimum of 400 hole-by-hole scores is required from players representing the full range of Course Handicap. This is similar to the method in "Section 17-2a" of allocating handicap strokes using a large number of scores, but instead of comparing an average of scores among two distinctively-defined groups (Group A and B) with a large disparity in Course Handicap, the regression method uses all scores covering the whole Course Handicap range to allocate handicap strokes.

Step 1: Collect a large number N (at least 400 (more is better)) hole-by-hole scores from the same tee and gender.

Step 2: For each hole, take each of the hole-by-hole Course Handicap/score pairs and

Compute:

1) The sum of all the Course Handicaps = S1 (this value is the same for all holes)

2) The sum of all the scores = S2

3) Compute square of each Course Handicap and then sum all these squared values = S3 (this value is also the same for all holes)

4) Compute the product of Course Handicap multiplied by score for each handicap/score pair and then sum these values = S4

5) Compute the difference factor (DF)

DF = (N x S4) - (S1 x S2) divided by (N x S3) - (S1²)

Step 3: Rank all holes based on this DF value. The greater the DF the greater the expected score difference between a low and a high handicapped golfer (i.e., the hole with largest DF is handicap-stroke hole number one).

Step 4: Assign the final allocation of handicap strokes based on Committee's discretion.