What a handicap is for
Golf is close to unique in letting people of wildly different standards play the same match and both have a chance. That only works because of the handicap. It is a measure of what you are capable of when you play well, not an average of how you usually play, and the distinction matters more than anything else on this page.
Your handicap is built from your best recent rounds. Most of your scores never touch it. That is deliberate: the system is trying to answer "how good is this golfer on a good day", because that is the fair basis for a match.
The three numbers people mix up
Almost every handicap argument in a clubhouse comes from these three being used as if they were the same thing. They are not.
Handicap Index
One number, portable, to one decimal place. It belongs to you and not to any course. This is the thing people mean by "my handicap" when they say 14.2 rather than 14.
Course Handicap
What your Index becomes on the course and tees you are about to play. A harder course gives you more shots. This is the number you actually get on the card.
Playing Handicap
Course Handicap with the format's allowance applied. Some competitions give you a percentage of it rather than the lot, singles matchplay being the usual one. For an ordinary round with your mates, Playing Handicap and Course Handicap are the same thing.
How one round becomes one number
Every qualifying round produces a score differential. It answers a narrow question: how good was that round, on that course, from those tees, compared with what a scratch golfer would be expected to shoot.
113 is the slope of a course of average difficulty, so dividing by the slope of the course you actually played scales your round back to that standard. It is what lets a 92 at a brutal links and an 88 at a gentle parkland be compared honestly.
Course rating and slope
Both are printed on the card and usually on the tee box, and both are measured for each set of tees.
- Course Rating is the score a scratch golfer is expected to shoot. It is rarely a round number: 71.2 or 73.8, not 72. It is not par, and the gap between the two is exactly why the Course Handicap formula has a "minus par" in it.
- Slope Rating is how much harder the course gets for a bogey golfer than for a scratch golfer. 113 is average. Higher slope means a higher handicapper needs proportionally more shots there.
Ratings are gender-specific, because they are measured against a scratch and a bogey player of one gender. A ladies' rating is not a men's rating of the same markers, so using the wrong one quietly hands out the wrong number of shots.
Best eight of your last twenty
Your Index is the average of your best differentials from your last twenty qualifying rounds. How many count depends on how many rounds you have, and at low round counts an adjustment is applied on top.
| Rounds | Best of | Adjustment |
|---|---|---|
| 3 | 1 | -2.0 |
| 4 | 1 | -1.0 |
| 5 | 1 | 0 |
| 6 | 2 | -1.0 |
| 7 to 8 | 2 | 0 |
| 9 to 11 | 3 | 0 |
| 12 to 14 | 4 | 0 |
| 15 to 16 | 5 | 0 |
| 17 to 18 | 6 | 0 |
| 19 | 7 | 0 |
| 20 | 8 | 0 |
Below three rounds there is no Index at all. The system wants 54 holes before it will stand behind a number, and that is the right call: one round tells you almost nothing.
This table is also the answer to the most common complaint in golf. You played well, your handicap did not move, and it feels broken. It is not. If the round was not better than your eighth best, it changed nothing, because it was not one of the eight being averaged.
The blow-up hole is capped
Before the differential is worked out, every hole is capped at net double bogey: par, plus two, plus any shots you get on that hole. A nine on a par four where you get a shot counts as a seven.
This is why a handicap is not wrecked by one lost ball. It is also why hole-by-hole scores matter: without them, the cap cannot be applied and your gross score is used as it stands.
Soft cap and hard cap
A handicap can come down as fast as your golf improves. Going up is deliberately slower, and that is what the caps do. Both work against your Low Handicap Index, the lowest Index you have held in the previous 365 days.
- Soft cap. Once your Index would rise more than 3.0 above your Low Handicap Index, everything past that 3.0 only counts at half value.
- Hard cap. It cannot rise more than 5.0 above your Low Handicap Index at all.
So a golfer whose Low Handicap Index is 12.0 cannot go above 17.0, however badly the year goes, until that low rolls out of the 365 day window.
The caps need a year of history, which is why the handicap calculator does not apply them to a handful of scores typed into a form. The app does, because the app has your record.
What counts as a round
Not every knock adds to your handicap. To count, a round needs a course with a rating and slope for the tees you played, and a score for every hole you played.
Nine holes
Nines count. They are combined with another nine rather than doubled, and the shots you receive are allocated over the nine you actually played rather than half of an eighteen and a shrug. Getting this wrong is worth several strokes, so it is worth checking that whatever you use handles it properly. SHANKED scores nines with the shots allocated properly, but does not add them to your index yet.
Stableford
A Stableford round is converted to an adjusted gross score first, then treated like any other. You do not lose the round just because you played points.
The ceiling
The maximum Handicap Index is 54.0, the same for everyone. It replaced the old split limits, and it exists so that a genuine beginner has a number rather than nothing.
Official handicaps, and honest ones
An official Handicap Index comes from a club affiliated to your national association, who hold your record and can produce it for a competition. If you want to play in county events or an open, that is what you need.
Everything else is the same maths, worked honestly, so you know roughly where you stand before somebody asks you on the first tee. SHANKED calculates your Index with the real algorithm, including the caps and net double bogey, and says plainly that it is not an official handicap. We would rather tell you that than let you find out in a car park.
Be wary of anything that offers you a handicap from an average of your scores, or that still applies a 0.96 multiplier. The first is not how WHS works and the second was retired when the world system came in.
Work out your own
Type in a few scores and see the whole thing done, differential by differential, including which rounds counted and which did not.