The following FAQs have been developed to explain how 9-hole scores are treated for handicap purposes under the 2024 update to the World Handicap System™:
WHS™ 2024: Treatment of 9-Hole ScoresFAQs and Example Application
How did the treatment of 9-hole scores change under the WHS™ in 2024?
Prior to January 2024, one 9-hole score must be combined with another to create an 18-hole Score Differential™ before it could be counted for handicap purposes.
Now, when a player posts a 9-hole score, the WHS will automatically calculate an 18-hole Score Differential for the round, based on the player’s 9-hole Score Differential and expected Score Differential based on their current Handicap Index®, allowing the 9-hole round to be considered in the player’s Handicap Index calculation right away.
As part of this change, golfers are required to play all 9 holes with a valid 9-hole Course Rating™ and Slope Rating™ instead of the previous minimum of 7 holes.
What are the benefits of this change?
The growing number of golfers who regularly play 9-hole rounds no longer have to wait for another 9-hole score for their Handicap Index to be updated.
In addition, it provides a better indicator of how a player will normally perform over 18 holes on a given day when compared to combining 9-hole scores from different days and under different playing conditions.
Finally, this new method produces a more consistent and comparable Handicap Index for golfers who post 9-hole scores. For example, under the previous method:
- Combining two independent 9-hole scores often resulted in more volatility and was highly dependent on the order in which scores are combined.
- It was also common for two good 9-hole scores to be combined that produce an 18-hole Score Differential that is better than any of the player’s 18-hole scores made over 18 consecutive holes. The impact was an artificially low Handicap Index.
How is a golfer’s expected score determined to create an 18-hole Score Differential?
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.
Here is an example of how a 9-hole score is converted into an 18-hole Score Differential:
A player with a Handicap Index of 14.0 posts a 9-hole score of 41. Based on Course Rating™ and Slope Rating™ of the tees played, this results in a 9-hole Score Differential of 7.2. That value is then added to the player's expected 9-hole Score Differential to determine an 18-hole Score Differential of 15.7, which will be entered into the player's scoring record immediately.
Important: The expected 9-hole Score Differential is based on the player’s current Handicap Index – so it does not change based on how or where the 9-hole round was played.
CLICK HERE for an infographic on this topic.
Why not double the 9-hole score that was posted to reflect how a golfer played on a particular day?
If you have posted a good 9-hole score relative to your Handicap Index, you might have noticed that the 18-hole Score Differential is higher than if the score from the 9 holes played were doubled. This is because the Score Differential from the 9 holes played was combined with an expected Score Differential based on your current Handicap Index.
Given that, in general, golfers play to their Handicap Index about 20% of the time, use of expected score is going to provide more realistic results than assuming performance on the 9 holes played will be maintained over a subsequent 9 holes. If the latter approach was taken, many golfers would end up with a Handicap Index that is too low – making it more difficult to compete against others.
When establishing a Handicap Index, how are 9-hole scores treated?
To establish a Handicap Index, a player must play and post a total of 54 holes, which can be made up of 9- and/or 18-hole scores. The use of expected score does not come into play until a golfer plays and posts 54 individual hole scores.
Once the player has posted scores from a total of 54 holes and an expected score can be determined for the player, an 18-hole Score Differential will be calculated for each 9-hole score and displayed within their scoring record. At this time the player will have established their initial Handicap Index.