9 hole general play handicap

[Voyager EMH]

Interesting.

The OP has an HI of 6.0

He plays 9 holes with a SR of 128 in 2.8 shots over CR.

I believe he has played below his HI not above it.

My calculations show this to be the case, if they are correct.

9-hole CH is 5 (rounded from 4.6) and he completes the holes in 2.8 shots over CR. (Is this playing above or below his handicap?)

18-hole CH based on the same 9 holes is 9. (Rounded from 9.2)

When setting out to play the 9 holes, it does not seem reasonable that to play below a 6.0 HI the OP must complete the 9 holes in 1.8 over CR.

Surely, 2.8 shots over CR for 9 holes is not playing above a HI of 6.0 ?
Something wrong with the system, if this were true, in my view.

 

[Voyager EMH]

I found an online 9-hole differential calculator and got this result

 

[Voyager EMH]

A screen shot of my own spreadsheet that I designed 18 months ago for this purpose

 

[Voyager EMH]

Anybody need any further convincing?

 

[Voyager EMH]

Hi @Kennysarmy, did you get this issue resolved?

 

[Kennysarmy]

Hi @Kennysarmy, did you get this issue resolved?

No.

Not had chance yet - maybe I will drop them an email and find out why the discrepency.

 

[Kennysarmy]

This still makes no sense to me....but this is their reply.

 

[Voyager EMH]

Its wrong.

The "Scaled up 9 holes" should be 40.

Your 9-hole handicap was 4.6 (rounded to 5) and your 18-hole handicap based on the same 9-holes was 9.2 (rounded to 9)

(NB: If you played twice round your front nine as an 18-hole score, your CH would be 9)

You had a handicap of 5 for the nine holes played and you should have a handicap of 4 for the "scaling up" 9 holes.

9 nett pars plus one shot for the scaling up 9-holes should be 40 not 41.

They have made an error.

Posts #22 and #23 show the correct calculation.

 

[wjemather]

My understanding is that handicap strokes allocated to the second (scaling-up) 9 are simply based on the SI allocations (which are odds) - strokes used (from the 9-hole Course Handicap) on the holes actually played are irrelevant for this.

 

[Voyager EMH]

My understanding is that handicap strokes allocated to the second (scaling-up) 9 are simply based on the SI allocations (which are odds) - strokes used (from the 9-hole Course Handicap) on the holes actually played are irrelevant for this.

See post #19.
The scaling up 9 holes is based on the 18-hole handicap (9 in this case, 2 x 4.6) for the same nine holes.
So the payer has a handicap of 9 for the 9 holes played and the scaling up 9 together.
He has five shots on the holes played and 4 shots on the scaling up 9.
There is no calculation that can give him a handicap of 10 in this case.

 

[wjemather]

See post #19.
The scaling up 9 holes is based on the 18-hole handicap (9 in this case, 2 x 4.6) for the same nine holes.
So the payer has a handicap of 9 for the 9 holes played and the scaling up 9 together.
He has five shots on the holes played and 4 shots on the scaling up 9.
There is no calculation that can give him a handicap of 10 in this case.

The two 9s are considered independently. You do not subtract the 9-hole CH from the 18-hole CH to establish the strokes received for the second (scaling-up) 9.

If the player has a 9-hole CH of 5 for the 9 holes played, and an 18-hole CH of 9 (to be allocated to the 9 holes for scaling up); these strokes for scaling up are allocated per the SIs (using odd numbered indexes), so 5 strokes are received for this 9 (on holes with 18-hole SIs 1, 3, 5, 7, 9).

The purpose of doing the calculation this way (rather than simply applying the 9hCH to both 9s) is so that, for a player with an 18-hole CH that is 1 greater than 2 x their 9-hole CH (e.g. unrounded 9hCH = 0.3, such that 9hCH = 0 and 18hCH = 1) that stroke is accounted for when calculating the score differential.

 

[Voyager EMH]

The two 9s are considered independently. You do not subtract the 9-hole CH from the 18-hole CH to establish the strokes received for the second (scaling-up) 9.
I do and I did, although it is not necessary to do so, it does produce the correct result.
The 2 nines are not considered independently - they are linked by the fact that the "scaling up" nine holes are based on the 18-hole handicap for the same nine holes.
In many cases the handicap for the "scaling up" nine holes will be the same as the handicap for the nine holes played.
In other cases it could be one more or one less.

If the player has a 9-hole CH of 5 for the 9 holes played, and an 18-hole CH of 9 (to be allocated to the 9 holes for scaling up); these strokes for scaling up are allocated per the SIs (using odd numbered indexes), so 5 strokes are received for this 9 (on holes with 18-hole SIs 1, 3, 5, 7, 9).
It matters not whether the front nine holes have odd or even numbered stroke indexes. The player receives 5 shots. These shots are not "allocated per hole" except for the nett double bogey limit for handicapping purposes.
If he were to be playing the same nine holes again as an 18-hole round then he would receive 4 shots on the second nine.
Similarly, as his scaled up nine is based on that 18-hole handicap for the same nine holes, he receives 4 shots. And 9 nett pars plus one shot is a 5-over par 40. (Not 41)

The purpose of doing the calculation this way (rather than simply applying the 9hCH to both 9s) is so that, for a player with an 18-hole CH that is 1 greater than 2 x their 9-hole CH (e.g. unrounded 9hCH = 0.3, such that 9hCH = 0 and 18hCH = 1) that stroke is accounted for when calculating the score differential.

This example is, in a way, the opposite of the OP's case. The OP has an 18-hole CH that is one less than 2 x his 9-hole CH. (9hCH = 5 and 18hCH = 9)
On the OP's course a player would need to have a HI of +1.6 to obtain a 9-hole CH of 0.3.
Such a player would have a scaled up nine of 2 over par. (Nine nett pars plus one shot)
The range of differentials obtained for front nine scores is this...




I believe my calculations are correct.
I believe my calculations and the on-line calculator in posts #22 and #23 are correct.

I would be willing to admit I am wrong, if someone can show me the correct calculations with a detailed and convincing explanation of those calculations.

 

[wjemather]

I believe my calculations are correct.
I believe my calculations and the on-line calculator in posts #22 and #23 are correct.

I would be willing to admit I am wrong, if someone can show me the correct calculations with a detailed and convincing explanation of those calculations.

Actual score differentials produced by the system should be all you the evidence you need to confirm your calculations are not correct.

I have explained my understanding of how the calculation works, which seems to be the only method from which those differentials can be produced that is consistent with the rules -
obviously, a better example in the rules would have made the methodology clear.

 

[Deleted member 3432]

Play 18 holes and job sorted

 

[Voyager EMH]

The rule states that the scaling up nine holes is based on the 18-hole handicap for the nine holes played.

The handicap for the scaling up nine holes is not an exact duplicate of the handicap for the nine holes actually played.
Sometimes it will be the same and sometimes it will be one shot more or one shot less.

If anyone can find a calculation in the rules whereby the OP gets a 10 handicap for his scenario, please let me know.
I have done the calculations based on the formulas shown in the rules.

If anyone can quote those rules and formulas and produce results different from mine, please show - with details.

 

[wjemather]

The rule states that the scaling up nine holes is based on the 18-hole handicap for the nine holes played.

The handicap for the scaling up nine holes is not an exact duplicate of the handicap for the nine holes actually played.
Sometimes it will be the same and sometimes it will be one shot more or one shot less.

If anyone can find a calculation in the rules whereby the OP gets a 10 handicap for his scenario, please let me know.
I have done the calculations based on the formulas shown in the rules.

If anyone can quote those rules and formulas and produce results different from mine, please show - with details.

This isn't what is happening, and you have added something to the rules that simply isn't there (i.e. that the strokes received on the second 9 are the remainder of the difference between the 18 and 9 hole Course Handicaps).

Each 9 is treated independently.

For the second 9, take the (2x9-hole) 18-hole handicap and apply strokes accordingly, based on the odd numbered SIs being on that 9. Using this, total a nett bogey and 8 nett pars.

 

[Voyager EMH]

The OP has a HI of 6.0

He completed 9 holes in 2.8 shots over the CR. This gives a "stand alone" differential of 2.5.

He has clearly played to a standard below his HI of 6.0 albeit over 9 holes only.

The 9-hole differential of 2.5 is scaled up to 5.8 for handicapping purposes in this scenario. He has played better than his HI.

Scaling up a 9-hole differential of 2.5 to an 18-hole differential of 6.7 for a player with a HI of 6.0 who has played nine holes in merely 2.8 shots over the CR is utter nonsense.

My calculations are correct, they make good sense and they agree with all online calculators that I have seen and used. (see post #22 and #23)

If his scaling up nine holes uses a 5 handicap then this gives him an 18-hole handicap of 10 - that is wrong - his 18-hole handicap is 9 - which is 5 for the holes played and 4 for the scaling up 9-holes. This produces a result which is both sensible and correct.

If the OP's HI were 6.3 then the correct calculation does then give a differential of 6.7 for a 9-hole score of 39 as the 9-hole handicap is 5 and the 18-hole handicap is 10.

 

[wjemather]

The OP has a HI of 6.0

He completed 9 holes in 2.8 shots over the CR. This gives a "stand alone" differential of 2.5.

He has clearly played to a standard below his HI of 6.0 albeit over 9 holes only.

The 9-hole differential of 2.5 is scaled up to 5.8 for handicapping purposes in this scenario. He has played better than his HI.

Scaling up a 9-hole differential of 2.5 to an 18-hole differential of 6.7 for a player with a HI of 6.0 who has played nine holes in merely 2.8 shots over the CR is utter nonsense.

My calculations are correct, they make good sense and they agree with all online calculators that I have seen and used. (see post #22 and #23)

If his scaling up nine holes uses a 5 handicap then this gives him an 18-hole handicap of 10 - that is wrong - his 18-hole handicap is 9 - which is 5 for the holes played and 4 for the scaling up 9-holes. This produces a result which is both sensible and correct.

If the OP's HI were 6.3 then the correct calculation does then give a differential of 6.7 for a 9-hole score of 39 as the 9-hole handicap is 5 and the 18-hole handicap is 10.

The only thing that matters is the diffs the system produces - what you, I, or any number of online calculators come up with is irrelevant. I am aware that what you are saying is consistent with the example in CONGU's guidance, however it adds something that is not actually in the rules, and importantly, it is evidently not how the diffs appear to be calculated by the system. I have offered methodology consistent with the rules that would produce the same diffs as the system - that is all.

 

[rulefan]

I have offered methodology consistent with the rules that would produce the same diffs as the system - that is all.

The proof of the pudding ..........

 

[Voyager EMH]

It would have been a very simple matter for the rules to state that the scaling-up nine holes uses exactly the same handicap as the nine holes played.
The rules do not state this.

"The system" is what the rules state (or should be)

Any calculations that any handicapping authority use are of human creation. A program to produce those calculations can contain human errors in its composition.
That human (or group) of humans could have made errors in this case.

I have made my calculations based on what the rules state.
It seems that others have done the same.

I have said before, I am ready, willing and able to be convinced that I am wrong. That has not yet happened.

In a previous thread I had a devil-of-a-job convincing people here that an 18-hole handicap based on the same nine holes is not always simply a doubling of the 9-hole handicap.
This has given me experience of holding a minority view that was correct.