When golfers first sign up with MyScorecard they are given the choice of a 9-hole or
an 18-hole handicap. For those who sometimes play nine and sometimes play eighteen, this can be a
confusing decision. In this article, we hope to shed some light on the difference between the two handicaps
and which may be right for you.
Before we dive in, you should have a basic understanding of how your handicap is calculated.
At the fundamental level we take your score and adjust it for the course difficulty by subtracting
the course rating and then dividing the result by the course slope. The resulting number is called the 'differential' and
the formula for reference is
(score - rating) * (113 / slope). (Please note that we have left out some very
important steps that are not relevant for this discussion - we would encourage you to visit the
article explaning the Handicap Formula
, also found in this section of the
When we talk to MyScorecard members about 9-hole handicaps, the same four questions tend to be asked:
What is a 9-hole handicap?
- What is a 9-hole handicap?
- What adjustment do I need to make to track a 9-hole handicap?
- Can I enter both 9 and 18-hole scores into my Scorecard?
- So which type of handicap should I use (or does it really matter)?
In this busy day and age, many golfers don't have time to get in a full 18 holes
every time they play. In fact, quite a few only play 9 holes at a time. Instead of forcing
these golfers to combine their scores every time they play, the USGA created a 9-hole
handicap, which is denoted by an "N" (as in 12.2N). Golfers who have 9-hole handicaps can compete as normal
against other 9-hole handicap players by giving the difference between their handicaps over the nine
holes (a 9N gives a 12N three strokes on a course with a 113 slope - but only on nine holes. If they play
eighteen, the 12N receives 6 strokes ). When a 9-hole handicap golfer plays against an 18-hole handicap golfer,
they simply double their handicap (12N becomes a 24) and are able to compete fairly.
What adjustments do I need to make to track a 9-hole handicap?
It turns out that the exact same formula is used to calculate both 9-hole and 18-hole handicaps.
The only thing that changes is the rating number. Nine-hole handicappers need to use the 9-hole rating or halve the
18-hole rating when entering their scores. From a quick look at the handicap calculation, you can see
how entering an 18-hole rating (70.1) when tracking a 9-hole score (46) results in a negative differential
and ruins the handicap calculation.
(46 - 70.1) * (113 / 121) = -23
The rating traditionally denotes what the "Scratch" golfer would shoot on eighteen holes.
We halve the number and that allows an approximation of what the "Scratch" golfer would shoot on nine holes.
The slope number doesn't change because that denotes how much harder the course is for a "Bogey" golfer
rather than for a "Scratch" golfer. If the course is twice as hard for eighteen holes, it still stays twice as hard for
nine holes (more information on the slope and the rating can be found in the article discussing
the slope and rating
in this section).
So it would seem that if a golfer entered the correct rating numbers, they could enter both 9-hole and
18-hole rounds into their scorecard. Well, not exactly. Let's take the example below where
a golfer plays two rounds, the first on eighteen holes and the second on nine. We'll calculate the differential for each:
(46 - 35.1) * (113 / 121) = 10.2
(92 - 70.2) * (113 / 121) = 20.4
The next step in the handicap calculation is to take the best ten differentials from the last twenty
scores. But wait - our golfer would have to have a pretty amazing round for any 18-hole differential
to actually be lower than a 9-hole differential. For those who evenly mix 9-hole scores and 18-hole
scores on their Scorecard, there's over a 99% chance that all the stars will appear next to the 9-hole
scores. In fact, the handicap calculation will almost always choose 9-hole scores over 18-hole scores
- even if they are much worse games - thus skewing your handicap.
Avoiding this skew is the reason you should only enter in 9-hole scores, or 18-hole scores - but not both.
So which type of handicap should I use (or does it really matter)?
If you shoot half your score on nine-holes (46 versus 92) and
then divide the rating in half (35.1 versus 70.2), does it really matter whether you use a 9-hole or an 18-hole handicap?
Are they not essentially interchangeable?
Well, again not exactly. The above assumption rests on the fact that every time you play eighteen holes
you'll have the same score on both nines. But that isn't true - we're not yet sure as to whether
you end up with a better or worse handicap (any thoughts from the statistically inclined are
most welcome), but it will be slightly different.
As an example, we borrowed the scores from one of our members. As you can see, the distribution
of their differentials when looking on a 9-hole basis is much wider than when looking on an
But a much more important reason goes back to the original intent of the handicap formula,
which was to provide an even basis of competition for all golfers. Much like computer operating systems,
such a standard only really works when used by a majority of the people. To use a different handicap
formula defeats the purpose of the handicap system. While the differences between 9 and 18-hole
handicapping schemes may be minimal, when in doubt you should choose the handicap method that
most people use - the 18-hole handicapping method. Only when an 18-hole handicap is truly
an inconvenience should you choose to use a 9-hole handicap.