Question re WHS

[Mephistopheles]

When does an extreme weather adjustment happen?
Played a medal this week in awful weather, umpteen NRs and nobody beat their handicap. Yet no weather adjustment.
Does the adjustment also kick in if the weather and course conditions are in your favour and a number of scores come in under handicap?

 

[Wabinez]

There is no such thing as an extreme weather adjustment. You have the Plating Conditions Calculation (PCC), which can range from -1 to +3, and will kick in if the system detects that %s of players have scored outside of their expected range.

The formula is proprietary and so no-one really knows what the ranges are, and the exact calculation. It doesn’t matter if no-one ‘beat their handicap’ (that’s a can of worms anyways, as you need to relate to CR, rather than Par), but if some/a lot of the field played within their expected range for their index…PCC won’t move

Seel https://www.randa.org/roh/the-rules-of-handicapping/rule-5 and it’s 5.6 you want

 

[wjemather]

@Wabinez is correct in that the expected ranges are not public, however we can make a reasonable estimate and consequently a better judgement of when PCC will kick-in.

It's reasonable to assume that the expected range will extend a few strokes either side of average scores. Since average scores are 3-4 strokes above handicap, the expected range would therefore be in the region of 0-1 to 7-8 strokes above handicap. From this, it's easy to see that 'playing to handicap' is at the extreme end of the range, so is not a good guide to judging whether PCC will be non-zero.

It's also important to remember that a player can NR (which, as a hole score, is just a single nett double bogey for handicapping) and still return a score within (or better than) their expected range.

 

[D-S]

Do we have any idea if there is a minimum number of score entries on a day to produce a PCC change?

 

[wjemather]

Do we have any idea if there is a minimum number of score entries on a day to produce a PCC change?

Minimum 8 scores to trigger the process.

 

[rulefan]

@Wabinez is correct in that the expected ranges are not public, however we can make a reasonable estimate and consequently a better judgement of when PCC will kick-in.

It's reasonable to assume that the expected range will extend a few strokes either side of average scores. Since average scores are 3-4 strokes above handicap, the expected range would therefore be in the region of 0-1 to 7-8 strokes above handicap. From this, it's easy to see that 'playing to handicap' is at the extreme end of the range, so is not a good guide to judging whether PCC will be non-zero.

It's also important to remember that a player can NR (which, as a hole score, is just a single nett double bogey for handicapping) and still return a score within (or better than) their expected range.

Does it not also depend on the proportional representation of handicaps in the field? I understood that individual scores were examined and assumed the range would be greater as handicaps increase.

 

[wjemather]

Does it not also depend on the proportional representation of handicaps in the field? I understood that individual scores were examined and assumed the range would be greater as handicaps increase.

I deliberately over-simplified with the aim of providing a (very) basic overview and more appropriate reference point for a rule of thumb (than 'playing-to-handicap').
Broader expected ranges with higher indexes would be a reasonable assumption.
Scores from lower/higher handicappers are not given more/less weight than any others, however scores from players with indexes above 36.0 are not used, and nor are scaled-up scores.

 

[rulefan]

Scores from lower/higher handicappers are not given more/less weight than any others, however scores from players with indexes above 36.0 are not used, and nor are scaled-up scores.

Thanks. I was aware of the first two but not of the third.

 

[IanM]

Best to forget about it and see what figure magically appears the following morning!

I'm sort of serious... they've not made the detail of the maths public. The formula was changed, we're seeing more regular adjustments now.

One of my mates calls it the SSI. (Shhht Score Index) rather than anything weather related. He may have a point.

 

[Tower]

Best to forget about it and see what figure magically appears the following morning!

I'm sort of serious... they've not made the detail of the maths public. The formula was changed, we're seeing more regular adjustments now.

One of my mates calls it the SSI. (Shhht Score Index) rather than anything weather related. He may have a point.

Your mate was fundamentally correct as it's not specifically weather relateted. It merely checks the day's scores against an expected range, so course setup, or a combo of both, can also affect the PCC.

 

[5OTT]

I have gone out for a round this morning with a new member, he has recently got his handicap and wants to get in as many cards as possible ready for the new season next year. Ideally he wants to get 20 cards in so he feels he has a genuine Handicap, I said that i would also put a card in as well, we realised when we registered for the round that we selected non qualifying, does this mean when we enter the score it wont count against the handicap calculation or will it still register for the HCP Calculation?

 

[wjemather]

I have gone out for a round this morning with a new member, he has recently got his handicap and wants to get in as many cards as possible ready for the new season next year. Ideally he wants to get 20 cards in so he feels he has a genuine Handicap, I said that i would also put a card in as well, we realised when we registered for the round that we selected non qualifying, does this mean when we enter the score it wont count against the handicap calculation or will it still register for the HCP Calculation?

It won't count. However if you speak to your handicap committee and explain what happened, they should accept it and re-enter your scores on the handicap system directly.

They should also disable entry of non-qualifying General Play scores on the system - it's utterly ludicrous that this is even an option.

 

[Alan Clifford]

Your mate was fundamentally correct as it's not specifically weather relateted. It merely checks the day's scores against an expected range, so course setup, or a combo of both, can also affect the PCC.

If we put cards in the box, they are not entered into the "system" every day. I complained about this and was told that not enough people submit scores for handicap to trigger a pcc. Then we had a pcc! I reckon we had a society who didn't know the course and they submitted scores on the app.

 

[SwingsitlikeHogan]

Simple question given discussion above. Why is the PCC algorithm proprietary and why is it secret? The obvious answer to the second part is ‘because it’s proprietary’…but if that’s the case why is the basic framework not public knowledge, and why does the R&A and USGA not own and publish the requirements for the PCC algorithm?

 

[wjemather]

Simple question given discussion above. Why is the PCC algorithm proprietary and why is it secret? The obvious answer to the second part is ‘because it’s proprietary’…but if that’s the case why is the basic framework not public knowledge, and why does the R&A and USGA not own and publish the requirements for the PCC algorithm?

Like most of the Course Rating System, certain aspects of WHS (i.e. the non-simple calculations) are not openly published (probably) because the USGA are seeking to protect their intellectual property and prevent copying.

The basic framework of PCC is public knowledge - it's described in the rules of handicapping. However, you would need an understanding of degree-level maths/stats to understand what is actually being described and knowledge of scoring patterns in order to extrapolate that to a reasonable estimation of when it might kick-in (e.g. players average 3-4 over handicap, so that should be the reference point, not playing to handicap, 36 points, nett par, or anything else).

 

[SwingsitlikeHogan]

Like most of the Course Rating System, certain aspects of WHS (i.e. the non-simple calculations) are not openly published (probably) because the USGA are seeking to protect their intellectual property and prevent copying.

The basic framework of PCC is public knowledge - it's described in the rules of handicapping. However, you would need an understanding of degree-level maths/stats to understand what is actually being described and knowledge of scoring patterns in order to extrapolate that to a reasonable estimation of when it might kick-in (e.g. players average 3-4 over handicap, so that should be the reference point, not playing to handicap, 36 points, nett par, or anything else).

If I was guessing I’d assume handicaps in any club will be normally distributed around the mean for the members with associated standard deviation. If the mean for any comp landed greater than, let’s say, the 2sigma (SDs) from the mean for the club then that is deemed an anomaly and a PCC adjustment is applied to correct that anomaly. It may be that a mean and SD is calculated on an ongoing basis for each player and the same ‘anomaly’ assessment is made and if the number of members scoring anomalously exceeds some variance from the number of members exceeding the club mean then a PCC adjustment is applied across the board. Or something of that nature. I dunno.

It needn’t be a secret. But I get that the USGA might want to avoid other organisations setting up and offering alternative handicaps…I think.

 

[wjemather]

If I was guessing I’d assume handicaps in any club will be normally distributed around the mean for the members with associated standard deviation. If the mean for any comp landed greater than, let’s say, the 2sigma (SDs) from the mean for the club then that is deemed an anomaly and a PCC adjustment is applied to correct that anomaly. It may be that a mean and SD is calculated on an ongoing basis for each player and the same ‘anomaly’ assessment is made and if the number of members scoring anomalously exceeds some variance from the number of members exceeding the club mean then a PCC adjustment is applied across the board. Or something of that nature. I dunno.

It needn’t be a secret. But I get that the USGA might want to avoid other organisations setting up and offering alternative handicaps…I think.

Scoring patterns do not follow a normal distribution.
The indication is that the calculation of expected scoring range is done for each HI, with a PCC adjustment being determined on the proportion of scores returned above/below their individual expected range.