Handicap Index

Handicap Index is a measure of a player's demonstrated ability calculated against the Slope Rating of a golf course of standard playing difficulty.
It represents a golfer's playing handicap on a course with a Neutral Slope Rating of 113.
It is calculated as a rolling average of the lowest 8 from the last 20 Score Differentials.
Each time a new score is submitted the average of the lowest 8 from the last 20 is re-calculated, which may or may not lead to a change of Handicap Index.
There are additional safegaurds to ensure that a player's handicap does not rise too quickly when a player is going through a spell of poor form.

Low Handicap Index (LHI)

A player's lowest Handicap Index during the last 12 months is used as an Anchor Point to limit increases in Handicap Index.
Soft CAP: Potential increases of Handicap Index to a figure greater than (LHI + 3) are limited by half the amount over three, e.g. 5 is limited to 4,  6 is limited to 4.5, etc. 
Hard CAP: The maximum that the Handicap Index can increase to is (LHI + 5).

Exceptional Scores

An adjustment to the Handicap Index after a very low score has been posted.
A reduction of -1 for scores between 7 and 9 below Handicap Index.
A reduction of -2 for scores 10 or more below Handicap Index.
The reduction is applied to the last 20 scores on the Scoring Record and drops off gradually over the next 20 rounds.

Click to see a short video about Handicap Index

New Handicaps

A New Player's Handicap Index is initially allocated at 2 less than the best of the Adjusted Gross Scores from 3 x 18 hole cards submitted. Cards can be submitted as 6 x 9 hole or some other combination. Subsequent Handicap Index calculations change as more scores are entered:

3 scores: lowest score -2
4 scores: lowest score -1
5 scores: lowest score
6 scores: average of lowest 2 scores -1
7 to 8 scores: average of lowest 2 scores
9 to 11 scores: average of lowest 3 scores
12 to 14 scores: average of lowest 4 scores
15 to 16 scores: average of lowest 5 scores
17 to 18 scores: average of lowest 6 scores
19 scores: average of lowest 7 scores
20 scores: average of lowest 8 scores