Handicap calculation
The handicap calculation is the score-based assessment of the rounds you play, from which your handicap results.
Every handicap-relevant round is converted into a so-called score differential under the World Handicap System. Alongside your stroke count, the Course Rating and the slope rating of the course played are included. This makes rounds on easy and on difficult courses comparable. For the Handicap Index, the best eight of the last twenty calculations then count. If fewer rounds are available, transitional rules apply.
An example makes this tangible: you play 92 strokes on a course with a course rating of 71.5 and a slope of 128. The calculation sets your stroke count against the course difficulty and produces a value of around 18. Whether this round changes your handicap depends on whether it belongs to your best eight. Registered private rounds, the so-called EDS rounds, are included in the calculation if you registered them in advance.
There are two typical misunderstandings. Firstly, not every weak round worsens the handicap, because it only counts if it falls among your best eight. Secondly, the round must be registered as handicap-relevant before the first tee shot, otherwise it does not enter the calculation. The background to the number itself is explained in the entry on the Handicap Index.
FAQ
Does a bad round immediately count against my handicap?
No. Only the best eight calculations from your last twenty rounds count for your index; a single weak day usually drops out of the scoring. Only when bad results pile up and good old ones drop out does your index rise noticeably.
When does a private round enter the calculation?
Only if you registered it as handicap-relevant before the first tee shot, for example as an EDS round. Nothing can be saved afterwards: without registering in advance the round does not count, no matter how good it was. Registration usually runs through your association's app or at the club office.
What happens if I abandon a registered round?
Abandoning a round is not a free pass. Anyone who quits without an important reason such as injury or a thunderstorm must expect the handicap committee to enter a penalty score. Better: play the round to the end and hand in the card, even if the day is not going well.