Handicap allowances

[Shilgy]

I was certain I knew the answer to this question but according to the USGA GHIN app I evidently do not.  When calculating the playing handicap for a certain event-say 90%- do you first calculate the course handicap and round up or down? So a 5 course handicap would stay a 5 playing handicap because it would be 4.5 rounded up? 
  OR do you take the 90% on the players index and calculate a daily course handicap aka playing handicap? It can make a difference if you are a “low 4” for example.
At my home course from the tees I usually play I am a 3.9 index and play to a 4 course handicap. A friend is a 4.4 index who also plays to a 4. If I plug us both into the handicap calculator using 90% the 3.9 drops to a 3 playing handicap and the 4.4 stays a 4.  For that matter another friend who is a 2.0 index, normally plays at 2, drops to a 1 using the allowance. 
  
Any guidance would be appreciated.

 

[Augster]

Playing handicap = Course handicap x playing allowance (90%, 80% etc. etc.)

 

PH is rounded up at .5 or higher. 

 

The kicker is that you don’t round until after the PH is found. So you don’t round the CH if you’re using a PH. I “believe” the app does this automatically, but I haven’t tested it. 
 

 

[Shilgy]

4 minutes ago, Augster said:

Playing handicap = Course handicap x playing allowance (90%, 80% etc. etc.)

 

PH is rounded up at .5 or higher. 

 

The kicker is that you don’t round until after the PH is found. So you don’t round the CH if you’re using a PH. I “believe” the app does this automatically, but I haven’t tested it. 
 

 

That is what I thought. But have cases as described.

[Augster]

What are the indexes of the players and what is the slope, course rating, and par of the course being played?

 

Should be easy to figure out from that information. 

[rogolf]

18 minutes ago, Augster said:

Playing handicap = Course handicap x playing allowance (90%, 80% etc. etc.)

 

PH is rounded up at .5 or higher. 

 

The kicker is that you don’t round until after the PH is found. So you don’t round the CH if you’re using a PH. I “believe” the app does this automatically, but I haven’t tested it. 
 

 

Isn't the course handicap always a whole number, ie, it's already rounded up or down, then the allowance is applied and rounded again to get to playing handicap (also a whole number)?

[Shilgy]

39 minutes ago, Augster said:

What are the indexes of the players and what is the slope, course rating, and par of the course being played?

 

Should be easy to figure out from that information. 

Use course at 71.4 127 and two players at 3.9 and 4.4.

 

27 minutes ago, rogolf said:

Isn't the course handicap always a whole number, ie, it's already rounded up or down, then the allowance is applied and rounded again to get to playing handicap (also a whole number)?

See above. That is what I thought but why would one 4 course handicap go down to a 3 playing handicap using 90% and the other 4 stays a 4?

[rogolf]

39 minutes ago, Shilgy said:

Use course at 71.4 127 and two players at 3.9 and 4.4.

 

See above. That is what I thought but why would one 4 course handicap go down to a 3 playing handicap using 90% and the other 4 stays a 4?

The method that I described (which might be incorrect) - rounding both the 3.9 and the 4.4 to 4, then applying the allowance and rounding again, would have them both as 4, which makes more sense to me.

 

[Sawgrass]

You only round once, at the end. 

[rogolf]

9 minutes ago, Sawgrass said:

You only round once, at the end. 

So, the course handicap is not a whole number?

The real formula is

playing handicap = handicap index X slope rating/113 X handicap allowance

then rounded to a whole number?

Is that published somewhere?

Edited September 15, 2020 by rogolf

[nsxguy]

2 hours ago, Augster said:

Playing handicap = Course handicap x playing allowance (90%, 80% etc. etc.)

 

PH is rounded up at .5 or higher. 

 

The kicker is that you don’t round until after the PH is found. So you don’t round the CH if you’re using a PH. I “believe” the app does this automatically, but I haven’t tested it. 
 

 

 

This.

 

If you're doing your own calcs you round twice, once to get the CH and once more when you take that and apply the handicap allowance and then round.

 

If you're using the USGA's calc page then of course THEY do the rounding to get the CH - then YOU apply the handicap allowance and round.

[nsxguy]

2 minutes ago, rogolf said:

So, the course handicap is not a whole number?

 

Yes it is. Mark the date. I believe Saw got one wrong. 

[rogolf]

10 minutes ago, nsxguy said:

 

Yes it is. Mark the date. I believe Saw got one wrong. 

Not keeping score, just participating and learning.

[Shilgy]

1 hour ago, nsxguy said:

 

This.

 

If you're doing your own calcs you round twice, once to get the CH and once more when you take that and apply the handicap allowance and then round.

 

If you're using the USGA's calc page then of course THEY do the rounding to get the CH - then YOU apply the handicap allowance and round.

I get that this is how we all understand how to calculate it. But the official GHIN app does not appear to agree.
 

Are you aware the percentage is available as a calculation on the app?

[Shilgy]

So it appears the official app does it wrong. A 4 course handicap cannot change to a 3 because of the 90%. And yet mine does on the app. And another friend goes from 2 to 1.

 

https://www.usga.org/content/usga/home-page/handicapping/roh/Content/rules/6 2 Playing Handicap Calculation.htm

[Colin L]

 

5 hours ago, rogolf said:

So, the course handicap is not a whole number?

The real formula is

playing handicap = handicap index X slope rating/113 X handicap allowance

then rounded to a whole number?

Is that published somewhere?

I'll need to go back through the text and my notes  later (heading out for a game right now) but my memory is that  the rule book tells us that the CH is a whole number and that the Playing Handicap formula is unqualified as  Course Handicap X Handicap Allowance.  If so, I would say that the CH in that formula has to be, by definition, a whole number.

 

It wouldn't be workable otherwise.  You take your Handicap Index to the course.  You use it to get your course handicap from  a chart in the clubhouse.  It gives you a whole number.  You arrive at the first tee for a four ball match and have to work out your Playing Handicaps.  You only know your Course Handicap as a whole number and can't be expected to start all over and  work it out to a decimal place prior to applying the Handicap Allowance.   

 

 

 

Edited September 15, 2020 by Colin L

[davep043]

I thought the applicable wording was in 6.2 concerning Playing Handicaps, but it actually appears at the end of the preceding section.  Here's the last sentence from Section 6.1 - Course Handicap Calculation:

 

"Otherwise, the full calculated value is retained and rounding occurs only after the Playing Handicap calculation."

 

If you use the GHIN app to determine handicaps for a group of players, you can select the Handicap Allowance and the Playing Handicap is calculated as described, with rounding only as the final step.  If your club uses GolfGenius software for competitions, the Playing Handicaps are calculated the same (correct per the rules) way. That's how a 4 becomes a 3, or a 2 becomes a 1.  The 4 may have been a 3.6 before rounding, but at 90% becomes 3.2, which rounds to 3.

[mark m]

Correct. Under the old pre-WHS you would first calculate the CH (which would be rounded). 

 

1. In the app - touch on the top "P.H." with the "circle i" next to it and a window will open saying what dave has posted above.

 

2. Also - here: 

 

https://www.usga.org/content/usga/home-page/handicapping/world-handicap-system/world-handicap-system-usga-golf-faqs/faqs---calculate-course-handicap-and-playing-handicap.html

 

Course Handicap and Playing Handicap

Q. How do I calculate my Course Handicap and Playing Handicap?

A. A Course Handicap is calculated using the following formula, but a mobile app or Course Handicap table at the course will do the math for you:

Course Handicap = Handicap Index x (Slope Rating / 113) + (Course Rating – par)

This number is rounded to the nearest whole number when applying net double bogey or net par adjustments. Otherwise, the unrounded result is retained and used to calculate a Playing Handicap.

Playing Handicap = Course Handicap x handicap allowance.

The result is then rounded to the nearest whole number. (Rule 6.1 and 6.2, Rules of Handicapping)

Edited September 15, 2020 by mark m

[HatsForBats]

I can confirm the GHIN app is using the non-rounded CH for the PH calculation. Just as others confirmed it should be. I stepped through all of the allowances on the GHIN App (95%, 90%, 85%) and in each case the column 'PH b4 Round x allow' (non-rounded Playing Handicap times the allowance)from the below image matched the GHIN app for each player. The issue I see is some players knowing their CH number (already rounded) and manually calculating their own playing handicap on that. It's bound to happen. Sometimes players lose a stroke and other times they gain a stroke.

 

 

 

 

[davep043]

45 minutes ago, HatsForBats said:

The issue I see is some players knowing their CH number (already rounded) and manually calculating their own playing handicap on that. It's bound to happen. Sometimes players lose a stroke and other times they gain a stroke.

 

The other issue that I would anticipate is that the maximum score, net double bogey, is based on the rounded Course Handicap, not the Playing Handicap, so the player would want to know his CH for posting purposes.  Its not an issue if a player posts scores hole by hole, but there's a potential for a little confusion if he'd prefer to just post the total.

I'm an engineer, and I've been trained since high-school days to leave all rounding until the very end of almost every set of calculations, so the new method seems like the "correct" way to do things.  Prior to this, we would round as many as three different times.  First, we'd calculate a Handicap.  Then, if different tees were involved, we'd adjust by the difference in Course Rating for the tees, and round again.  And if there was a ny kind of Handicap Allowance, we'd then do that calculation and round a third time.  Each time, a difference of 0.1 (or even less) could make a full stroke difference in the rounded number.  Do that three separate times, and rounding effects could become significant.

[rogolf]

54 minutes ago, HatsForBats said:

I can confirm the GHIN app is using the non-rounded CH for the PH calculation. Just as others confirmed it should be. I stepped through all of the allowances on the GHIN App (95%, 90%, 85%) and in each case the column 'PH b4 Round x allow' (non-rounded Playing Handicap times the allowance)from the below image matched the GHIN app for each player. The issue I see is some players knowing their CH number (already rounded) and manually calculating their own playing handicap on that. It's bound to happen. Sometimes players lose a stroke and other times they gain a stroke.

 

 

 

 

Are all of those numbers after the decimal place significant?  My math says 'no', the only number with any decimal is the course rating, and it has only one place after the decimal, hence all can only have one place after the decimal.

[Sawgrass]

1 hour ago, davep043 said:

I thought the applicable wording was in 6.2 concerning Playing Handicaps, but it actually appears at the end of the preceding section.  Here's the last sentence from Section 6.1 - Course Handicap Calculation:

 

"Otherwise, the full calculated value is retained and rounding occurs only after the Playing Handicap calculation."

 

If you use the GHIN app to determine handicaps for a group of players, you can select the Handicap Allowance and the Playing Handicap is calculated as described, with rounding only as the final step.  If your club uses GolfGenius software for competitions, the Playing Handicaps are calculated the same (correct per the rules) way. That's how a 4 becomes a 3, or a 2 becomes a 1.  The 4 may have been a 3.6 before rounding, but at 90% becomes 3.2, which rounds to 3.

Nicely done, Dave.  Yes, this is the statement supporting my earlier comment.

[davep043]

2 minutes ago, rogolf said:

Are all of those numbers after the decimal place significant?  My math says 'no', the only number with any decimal is the course rating, and it has only one place after the decimal, hence all can only have one place after the decimal.

I think you're probably right, but if you're using any type of automated method to run the calculations (from hand-held calculator to spreadsheet) those digits are just there, and there's no real reason to round or truncate until the very end.

[Sawgrass]

11 hours ago, rogolf said:

Not keeping score, just participating and learning.

I'm with you, Rogolf.  

[Sawgrass]

1 minute ago, davep043 said:

I think you're probably right, but if you're using any type of automated method to run the calculations (from hand-held calculator to spreadsheet) those digits are just there, and there's no real reason to round or truncate until the very end.

I wish I had the data to support the following, but I can't find it.  Nevertheless, I once saw that the USGA-affiliated Golf Genius App used a one-decimal number Course Handicap calculation to establish a player's Playing Handicap -- when the full string of decimal places would have yielded a different result.

 

I used to have to know how to play golf reasonably well to enjoy myself.  Then I found that I also needed to know the rules reasonably well to have a good time.  Now I see I also need a degree in computer science!

[Colin L]

18 minutes ago, davep043 said:

The other issue that I would anticipate is that the maximum score, net double bogey, is based on the rounded Course Handicap, not the Playing Handicap, so the player would want to know his CH for posting purposes.  Its not an issue if a player posts scores hole by hole, but there's a potential for a little confusion if he'd prefer to just post the total.

I'm an engineer, and I've been trained since high-school days to leave all rounding until the very end of almost every set of calculations, so the new method seems like the "correct" way to do things.  Prior to this, we would round as many as three different times.  First, we'd calculate a Handicap.  Then, if different tees were involved, we'd adjust by the difference in Course Rating for the tees, and round again.  And if there was a ny kind of Handicap Allowance, we'd then do that calculation and round a third time.  Each time, a difference of 0.1 (or even less) could make a full stroke difference in the rounded number.  Do that three separate times, and rounding effects could become significant.

 

[Colin L]

Thanks @davep043.   (Is that your name taken to 3 decimal places, by the way?)

 

I see that the Draft Rules did not have the statement you quoted from 6.1.   While I agree that automated  calculations can carry all those decimal places through, I am concerned about the occasions when playing handicaps will be worked out on the first tee as friends get together for a friendly fourball match.  We are well used at the moment to working out the difference between our handicaps and that of the back marker and applying a 90% modification in our heads but there is no way we could contemplate starting that process if we heard the first person saying his Course Handicap was 14.560391254 ?

 

Still, it's not a big deal I suppose.  We will happily determine our number of strokes for the match on the basis of the Course Handicap being a whole number. 

 

(A reminder:  the above is referring to the future because we in the UK are still a month and a bit away from changing over to the WHS.)

[Colin L]

Double entry - again.  Must learn to hit the edit button instead of the quote one.

Edited September 15, 2020 by Colin L

[davep043]

13 minutes ago, Sawgrass said:

I wish I had the data to support the following, but I can't find it.  Nevertheless, I once saw that the USGA-affiliated Golf Genius App used a one-decimal number Course Handicap calculation to establish a player's Playing Handicap -- when the full string of decimal places would have yielded a different result.

 

I used to have to know how to play golf reasonably well to enjoy myself.  Then I found that I also needed to know the rules reasonably well to have a good time.  Now I see I also need a degree in computer science!

My first instinct is to always retain as much precision in the calculation as possible until the end.  I really don't know what GG does in the calculations, I'm assuming that they follow the WHS requirement that all rounding wait until the end.  There's no reason that I know of for a computer program of any kind to do any rounding unless specifically directed to do so.

1 minute ago, Colin L said:

Thanks @davep043.   (Is that your name taken to 3 decimal places, by the way?)

 

I see that the Draft Rules did not have the statement you quoted from 6.1.   While I agree that automated  calculations can carry all those decimal places through, I am concerned about the occasions when playing handicaps will be worked out on the first tee as friends get together for a friendly fourball match.  We are well used at the moment to working out the difference between our handicaps and that of the back marker and applying a 90% modification in our heads but there is no way we could contemplate starting that process if we heard the first person saying his Course Handicap was 14.560391254 ?

We still play our informal fourballs using Course Handicap, with no reductions.  However, you can see the screenshot in @Shilgy's post, that's the information we can get on our phone app, and the handicap app will do the correct calculation of Playing Handicap very easily.  We've become accustomed to looking up handicaps on the first tee, ever since the daily revisions came into effect, so its really no trouble to take the extra step to get the correct Playing Handicap.  Besides, with the growing dependence many of us have on our phones, we've lost much of our ability to do simple math in our heads.

[nsxguy]

12 hours ago, nsxguy said:

 

Yes it is. Mark the date. I believe Saw got one wrong.

 

Fixed that for ya.

 

I shoulda known

 

 

 

Gotta say the USGA could've done a better job though.

 

Certainly could've put an asterisk, or a notation (see below) on 6.2a "The calculated Playing Handicap is rounded to the nearest whole number, with .5 rounded upwards." like "upwards*" or "upwards (See note below for Playing Handicaps)" EVEN THOUGH it's the previous 6.1 that has the verbiage, in the Interpretations section no less, at the very end - "Otherwise, the full calculated value is retained and rounding occurs only after the Playing Handicap calculation.", as in "Oh, BTW".

 

6.2 TITLED "Playing Handicap Calculation" says nothing about it. Only says "The calculated Playing Handicap is rounded to the nearest whole number, with .5 rounded upwards" Guess they figure one is reading the entire manual page by page.

 

Anyway, apologies Saw. Like I said, shoulda known. ?

 

 

 

 

 

[Sawgrass]

4 minutes ago, nsxguy said:

 

Fixed that for ya.

 

I shoulda known

 

 

 

Gotta say the USGA could've done a better job though.

 

Certainly could've put an asterisk, or a notation (see below) on 6.2a "The calculated Playing Handicap is rounded to the nearest whole number, with .5 rounded upwards." like "upwards*" or "upwards (See note below for Playing Handicaps)" EVEN THOUGH it's the previous 6.1 that has the verbiage, in the Interpretations section no less, at the very end - "Otherwise, the full calculated value is retained and rounding occurs only after the Playing Handicap calculation.", as in "Oh, BTW".

 

6.2 TITLED "Playing Handicap Calculation" says nothing about it. Only says "The calculated Playing Handicap is rounded to the nearest whole number, with .5 rounded upwards" Guess they figure one is reading the entire manual page by page.

 

Anyway, apologies Saw. Like I said, shoulda known. ?

 

 

 

 

 

I might have been right this time, but next time . . . ?

 

BTW, I agree with you that the requirement should have been added to different segments.