OT - How to calculate course handicap for a course with non-standard # of holes

[Matt Schoolfield]

I'm currently building the backend to allow people using the wiki to play a course live. However, because it's a wiki, people can add any course they like, with any rating and slope they like (official or not). The standard for calculating course handicap is obviously:

18 holes:

• Course Handicap = Handicap Index * (Slope Rating ÷ 113) + (Course Rating – par)

9 holes:

• Course Handicap = (Handicap Index/2) * (Slope Rating ÷ 113) + (Course Rating – par)

However, the USGA does not present a generalized form of this equation.

My question is whether the generalize form of the equation is the following:

• Course Handicap = ((number of holes ÷ 18) * Handicap Index) * (Slope Rating ÷ 113) + (Course Rating – par)

Is that correct? If not how is course handicap calculated for nonstandard courses like Shiskine, the Sandbox, or the 21?

[James Reader]

If you’re intending this to be used in the UK (as the reference to Shiskine suggests) then it’s worth noting that the “course rating - par” adjustment isn’t applied over here.

[Brian Finn]

Shiskine is rated for course rating and slope now, as are many (most?) courses in the UK.  63.3 / 99 from the whites, 62.0 / 97 from the yellows.  Edit:  just realized this is for their 18 hole setup, as the ~62-63 course rating would suggest.  I think par there is 42 or so for the 12 hole course.   

I am not aware of any par 3 courses (Bandon Preserve, Sandbox at Sand Valley, et al) that are rated for handicap purposes in this manner. 

[Matt Schoolfield]

I am not aware of any par 3 courses (Bandon Preserve, Sandbox at Sand Valley, et al) that are rated for handicap purposes in this manner.

Oops, I should not have included the sandbox, as I didn't look as to whether it had a rating/slope, was just thinking about the 17 holes.

If you’re intending this to be used in the UK (as the reference to Shiskine suggests) then it’s worth noting that the “course rating - par” adjustment isn’t applied over here.

I found the England Golf page with the equation:

Handicap Index® x (Slope Rating/113) = Course Handicap

I'm presuming this is the same for all of the R&A? I'm just hoping I can easily limit this to course country for the calculations at this point (World vs USA & Mexico).

[JohnVDB]

If you’re intending this to be used in the UK (as the reference to Shiskine suggests) then it’s worth noting that the “course rating - par” adjustment isn’t applied over here.

I hate that I get less strokes when I play in club events at Dornoch than I would get under the full system.


Their reasoning is that this is for people playing different tees and they never do that.  I point out that they have mixed couples events from different tees, but they don’t care. 

[Jason Thurman]

Shiskine is rated for course rating and slope now, as are many (most?) courses in the UK.  63.3 / 99 from the whites, 62.0 / 97 from the yellows.  Edit:  just realized this is for their 18 hole setup, as the ~62-63 course rating would suggest.  I think par there is 42 or so for the 12 hole course.   

I am not aware of any par 3 courses (Bandon Preserve, Sandbox at Sand Valley, et al) that are rated for handicap purposes in this manner.

I'm realizing that it's infuriating for me to discuss Shiskine now, because I "visited" it a couple weeks back but only was able to walk parts of the 4 holes closest to the clubhouse before my wife yelled "Why are we staring at a field?!" and took me to the pub down the street. I always thought of it as this really remote course that I'd probably never get to. The logistics of getting there were much easier than I ever imagined, but to go all that way and not play that funky little spot was sorta heartbreaking.


Anyway, I've spent a lot of time on their website in recent weeks. They have a "handicap" section in their main menu that breaks down how strokes are allocated whether playing 12 or 18. It may be helpful.


Does anyone know how the 18 hole course works? Sounds like it's a members-only routing and it doesn't look, on the scorecard, like it just involves repeating a few of the holes. I'm wondering if the 18 hole rating is based on playing a few "cross country" holes or something like that.