How is a Golfer's Expected Score Determined to Create an 18-Hole Score Differential When Posting a 9-Hole Score?

Once the player’s 9-hole Score Differential™ has been calculated, it is combined with an expected Score Differential based on the player’s current Handicap Index® to create an 18-hole Score Differential.

The expected score is based on the average Score Differential of a player with a given Handicap Index and a normal distribution of scores – so it is not specific to each player.

An expected score can be thought of as a neutral value, meaning that a good 9-hole round (relative to the player’s ability) will result in a good 18-hole Score Differential. An average 9-hole round will result in an average 18-hole Score Differential, etc. Click here for a detailed infographic by the USGA about use of expected score to create an 18-hole Score Differential.