For a full explanation go to CONGU - here

The new World Handicap System due to come into being at the end of 2020 is at the bottom of the page.

Brief Explanation

Category 1 = Handicaps of 5 or less.
Category 2 = Handicaps of 6 to 12 inclusive.
Category 3 = Handicaps of 13 to 20 inclusive.
Category 4 = Handicaps of 21 to 28 inclusive.
Category 5 = Handicaps of 29 to 36 inclusive.

A score is within a player’s Buffer Zone when a Nett Differential is within the following bands for his Handicap Category:

Category 1: 0 to +1
Category 2: 0 to +2
Category 3: 0 to +3
Category 4: 0 to +4
Category 5: 0 to +5

The recording of scores shall be kept by Nett Differential, i.e. the difference (+ or -) between the player’s nett score and the Competition Scratch Score (CSS).

If a player returns a Nett Differential within his Buffer Zone his Exact Handicap is not changed.

If a player returns a score with a Nett Differential above his Buffer Zone or records a No Return his Exact Handicap is increased by 0.1.

If a player returns a Nett Differential of less than zero his Exact Handicap is reduced by an amount per stroke that the Nett Differential is below zero, the amount per stroke being determined by his Handicap Category.

For example: If a player on 11.2 returns a score with a Nett Differential of +4 his Exact Handicap becomes 11.3. If he then returns a score with a Nett Differential of -7 his Exact Handicap is reduced by 7 x 0.2 = 1.4, i.e. to an Exact Handicap of 9.9 and his Playing Handicap is 10 which is immediately his new handicap.