World Handicap System Now Out (2020)

[bkuehn1952]

If one goes to the USGA site and looks at what is offered on the worldwide handicap system, due to debut in less than a year, the information is a bit vague.  This leads me to believe there continues to be negotiations and tweeks to the formula being proposed.  The article shared by @Rulesman from the Australian golf association had the most details, as far as I could see.

What we know (or think we know) - Changes from the current USA system

1. Currently the formula takes the 10 best differentials of the most recent 20.  The new formula will be the best 8 of 20. That will tend to lower handicap indices initially.

2. Currently a player needs at least five 18 hole differentials (or the equivalent combination of 9 hole differentials) in order to have a USGA index.  This will change to three (54 holes).

3. The current maximum indices are 36.4 (M) and 40.4 (F).  The new maximum will be a course handicap (not index) of 54.

4. Currently there is no adjustment for varying playing conditions. In 2020, there will be an adjustment made to differentials scored on days when the conditions are considered to be abnormally difficult.  The details are missing but it is thought the adjustments will be relatively small.

5. Currently, the ESC is based on a player's course handicap.  There is a table that displays the ESC for each range of course handicaps.  The new ESC maximums will be based on what a player's "net double bogey" would be.  In the past a player with an 8 course handicap just took double on whatever hole they experienced a disaster.  Now one needs to consider the hole's handicap rating.  As an "8" course handicapper, when the easiest hole on the course is a par 4, take a 6 (no strokes so net double is 6).  Hardest hole is a par 4, take a 7 (1 stroke given so a net double is 7).  This is a bit more complex so entering scores into the computer "hole by hole" might allow the computer program to figure out where you get strokes and what the ESC should be.  If one calculates ESC manually, knowing the hole's handicap ranking will be mandatory.

5. The article from Australia talked about a "soft cap" of "3".  The USGA talks about a "memory".  Essentially, there will be a system that compares one's lowest 12 month index against your current index.  If your current index is more than 3.0 higher than the 12 month low, you will be adjusted down.  The adjustment will be 50% of the difference between your 12 month low +3 and the computed index (clear as mud?).  An example is best.  Bob's 12 month low index is 12.5.  The latest index computation shows him to be 17.3.  That is more than 3.0 higher than his 12 month low so his index is adjusted down.  17.3 - 12.5 = 4.8      4.8 - 3.0 = 1.8       1.8 x .50 = .9   Bob's adjusted index is 16.4   (12.5 + 3.0 + .9). I think I have this right but absolutely check me on this item.

6. The article from Australia talked about a "hard cap" of 5.  I take that to mean that a player's current index can never be more than 5.0 higher than his/her 12 month low.

7. Again, the Australian article states that the ".93" factor will remain unchanged.  In the USA the formula uses a .96 "bonus for excellence".  If the Australian article is correct AND the formula is the same worldwide, we will have a .93 "bonus for excellence".

As our club's handicap chairman I have a keen interest in all this.  No doubt there will be some changes and new wrinkles before 2020.  If anyone comes across new information, be sure to share it here.  Thanks!

 

 

Edited January 13, 2019 by bkuehn1952

[dennyjones]

34 minutes ago, bkuehn1952 said:

If one goes to the USGA site and looks at what is offered on the worldwide handicap system, due to debut in less than a year, the information is a bit vague.  This leads me to believe there continues to be negotiations and tweeks to the formula being proposed.  The article shared by @Rulesman from the Australian golf association had the most details, as far as I could see.

What we know (or think we know) - Changes from the current USA system

1. Currently the formula takes the 10 best differentials of the most recent 20.  The new formula will be the best 8 of 20. That will tend to lower handicap indices initially.

2. Currently a player needs at least five 18 hole differentials (or the equivalent combination of 9 hole differentials) in order to have a USGA index.  This will change to three (54 holes).

3. The current maximum indices are 36.4 (M) and 40.4 (F).  The new maximum will be a course handicap (not index) of 54.

4. Currently there is no adjustment for varying playing conditions. In 2020, there will be an adjustment made to differentials scored on days when the conditions are considered to be abnormally difficult.  The details are missing but it is thought the adjustments will be relatively small.

5. Currently, the ESC is based on a player's course handicap.  There is a table that displays the ESC for each range of course handicaps.  The new ESC maximums will be based on what a player's "net double bogey" would be.  In the past a player with an 8 course handicap just took double on whatever hole they experienced a disaster.  Now one needs to consider the hole's handicap rating.  As an "8" course handicapper, when the easiest hole on the course is a par 4, take a 6 (no strokes so net double is 6).  Hardest hole is a par 4, take a 7 (1 stroke given so a net double is 7).  This is a bit more complex so entering scores into the computer "hole by hole" might allow the computer program to figure out where you get strokes and what the ESC should be.  If one calculates ESC manually, knowing the hole's handicap ranking will be mandatory.

5. The article from Australia talked about a "soft cap" of "3".  The USGA talks about a "memory".  Essentially, there will be a system that compares one's lowest 12 month index against your current index.  If your current index is more than 3.0 higher than the 12 month low, you will be adjusted down.  The adjustment will be 50% of the difference between your 12 month low +3 and the computed index (clear as mud?).  An example is best.  Bob's 12 month low index is 12.5.  The latest index computation shows him to be 17.3.  That is more than 3.0 higher than his 12 month low so his index is adjusted down.  17.3 - 12.5 = 4.8      4.8 - 3.0 = 1.8       1.8 x .50 = .9   Bob's adjusted index is 16.4   (12.5 + 3.0 + .9). I think I have this right but absolutely check me on this item.

6. The article from Australia talked about a "hard cap" of 5.  I take that to mean that a player's current index can never be more than 5.0 higher than his/her 12 month low.

7. Again, the Australian article states that the ".93" factor will remain unchanged.  In the USA the formula uses a .96 "bonus for excellence".  If the Australian article is correct AND the formula is the same worldwide, we will have a .93 "bonus for excellence".

As our club's handicap chairman I have a keen interest in all this.  No doubt there will be some changes and new wrinkles before 2020.  If anyone comes across new information, be sure to share it here.  Thanks!

 

 

Good luck with that!     Wow.  

[iacas]

@bkuehn1952, I don't think there's still much negotiating going on. The UK and some other places are just working to get courses rated.

Also, I think the 0.96 thing is going away entirely. That's one of the reasons they've reduced the 10/20 to 8/20. But the individuals I asked about that weren't 100% certain, but they said they were almost sure.

[Aguirre]

 

On 1/2/2019 at 1:08 PM, iacas said:

Unless you're in tight with someone at a local golf association or the USGA, I don't know that we'll ever be able to expose that information to you.

Why can't you expose it to us here?

Edited February 11, 2019 by Aguirre

[iacas]

5 hours ago, Aguirre said:

Why can't you expose it to us here?

For one thing… it’s not finalized.

[DaveP043]

32 minutes ago, iacas said:

For one thing… it’s not finalized.

@Aguirre was asking about the course rating adjustment due to "difficulty".  I haven't seen any details, but I know that in the UK they use a Competition Scratch Score, which is a similar approach.  The Standard Scratch Score is adjusted based on scores recorded on a specific day.  It seems possible that the WHS will use a similar approach, so you may want to review the CONGU manual here:

http://www.congu.co.uk/wp-content/uploads/2019/01/2019-CONGU-Manual.pdf

The calculation of the CSS begins on page 47.  Good luck!

On a side note, I'm very interested in seeing the final version of the WHS.  The single biggest topic that hasn't been covered in previous releases is that of which scores will be counted for handicap calculation.  In the USGA, we currently count almost all scores, in other systems it is limited more to competition scores only, with very few exceptions.  I think right now all of the Ruling Bodies are busy with training on the 2019 Rules of Golf, so I don't expect to see any more details on the 2020 Handicap rules for another couple of months.

[iacas]

5 minutes ago, DaveP043 said:

@Aguirre was asking about the course rating adjustment due to "difficulty".

I know what he was asking, and from what I've seen it won't really be like the CSS.

If you consider that the course rating and slope are two variables, and expected player scores and returned player scores are (or net differentials) are another point of data… you can start to see how the adjustments might go, favoring larger adjustments with larger sample sizes (and no adjustments given a small sample size - after all, odds are it'll be in the 12 out of 20 that don't matter).

[DaveP043]

1 hour ago, iacas said:

I know what he was asking, and from what I've seen it won't really be like the CSS.

If you consider that the course rating and slope are two variables, and expected player scores and returned player scores are (or net differentials) are another point of data… you can start to see how the adjustments might go, favoring larger adjustments with larger sample sizes (and no adjustments given a small sample size - after all, odds are it'll be in the 12 out of 20 that don't matter).

Sorry, I knew that you understood his question, I mentioned that so others wouldn't need to trace it back.  

I've scanned the CONGU manual a few times, and have always found it to be fairly difficult to wade through, and the USGA manual to be reasonable straightforward.  I'm hoping that the WHS Rules will be straighforward as well.

[iacas]

4 minutes ago, DaveP043 said:

I've scanned the CONGU manual a few times, and have always found it to be fairly difficult to wade through, and the USGA manual to be reasonable straightforward.  I'm hoping that the WHS Rules will be straighforward as well.

To go a bit further on what I was saying before… Consider this:

Here's a normal graph showing normal scores for a course playing under normal conditions. It's normalized for the fact that the average score is not the 8 of 20 rounds that account for your handicap, and will serve as the baseline for understanding how the adjustments will work.

So here's a normal day on a 73.0/133 rated course.

Don't read into the numbers much - I'm making numbers that make it easier for me to make a graph. The point is the relative differences in the lines.

So let's say there's a difficult day on the course - perhaps the greens are a bit faster, the rough is a bit thicker than usual, or the wind is up a bit, but the course is playing about the same yardage - and the scores are more closely represented by the orange line. If there are a lot of scores, you'll see an adjustment like this made to the standard scoring line (in grey):

You can see here that the slope must have likely increased, while the course rating likely changed by only 0.1 or 0.2 points, given the intercept of the grey line is still nearly 0.0.

Now let's say there's a very bad day on the course:

 

The adjustment may very well be the same as the "bad day" despite the trend line being much higher. Why? Well, perhaps significantly fewer golfers played on the "Very Bad Day" - maybe it was raining, windy, and miserable. The few golfers who played shot predictably much worse scores, but the data is too thin to make any massive changes. The handicapping system won't move the needle (the course rating/slope combo) very much if it doesn't have a lot of data to back it up.

Now, let's consider a Very Bad Day with a lot of players - maybe it's the club championship. The greens are slick, the tees are back, the rough is thick, and the holes are cut in the corners:

Because the course might see 150 people playing that day, and because the scores are higher, the adjustment may be quite a bit higher. In this graph, the slope changed to perhaps 145 (from 133) while the course rating might change to 74.5 (from 73.0). Because of the large sample size AND the large change from expected scoring, the algorithm can be somewhat aggressive in making an adjustment.

---

How's the math work out? Normally, shooting a 90 on the par 72 layout gets you a differential of (90-73.0)*(113/133) = 14.4. To get a 14.4 differential during the fictitious club championship, a golfer needs only to shoot 14.4*145/113+74.5 = 93. A score of 90 would yield a differential that day of 12.1.

---

An easy day with a relative large sample size of scores?

Maybe that's the adjustment: the course rating drops to 72.9 and the slope to 129 or something.

---

Now, again, this is all subject to change, and I'm intentionally leaving some parts out. Plus, I did this pretty quickly, as I have other things to do today, so again the numbers on the charts are pretty irrelevant - I just wanted to make graphs, so just mostly look at the lines, and consider the sides of the graphs as handicap versus score over par without attaching the actual numbers to them.

P.S. One additional note: the above, even with the "small sample size," assumes a minimum sample size has been met. If you have a day when only 30 golfers play, only 20 of which have handicaps… odds are pretty damn small that you're going to see any adjustment made.

[p1n9183]

The change is closer here in Argentina. 2 weeks ago the AAG came to my home course and re rated all tee boxes. The tips (blue) changed from 71,2 to 70,2 (Par 72). I always felt that the course was easier than it´s rating, now i have the proof! Now i´m 1 shot worst player for the world! Currently 1 handicap, i guess i will be 2 handicap after 20 rounds with the new rating. And around 2 index in the beginning of 2020.

[MacDutch]

On 2/12/2019 at 5:44 PM, p1n9183 said:

The change is closer here in Argentina. 2 weeks ago the AAG came to my home course and re rated all tee boxes. The tips (blue) changed from 71,2 to 70,2 (Par 72). I always felt that the course was easier than it´s rating, now i have the proof! Now i´m 1 shot worst player for the world! Currently 1 handicap, i guess i will be 2 handicap after 20 rounds with the new rating. And around 2 index in the beginning of 2020.

Worst 1.0 handicap player of the world 😂. Not sure if you are right about that, but still in the top 2% (or even better) players in the world. So don’t be to harsh on yourself.

My question to @iacas : you think this is still on for 1/1/20? I don’t hear anything about it from the Spanish and the Dutch golf federation.

[iacas]

1 hour ago, MacDutch said:

My question to @iacas : you think this is still on for 1/1/20? I don’t hear anything about it from the Spanish and the Dutch golf federation.

Yes.

So far as I know.

[mauricio]

I heard about the schedule here in Brazil, they're gonna run a seminar probably in May with Rating calibration. They say this year they're testing everything and will be running on 2020. There'll be seminars in 7 countries.

[DaveP043]

For the 2019 Rules of Golf, a "Proof Copy" was released in March of 2018.  I won't be surprised if we see a similar schedule for the 2020 World Handicap System, with a pretty detailed release sometime this spring.  I'm sure all of the local golf associations are busy right now with educational seminars around the 2019 Rules of Golf, they may want to get that over before they turn their attention to another pretty significant change.

[iacas]

4 minutes ago, DaveP043 said:

For the 2019 Rules of Golf, a "Proof Copy" was released in March of 2018.  I won't be surprised if we see a similar schedule for the 2020 World Handicap System, with a pretty detailed release sometime this spring.  I'm sure all of the local golf associations are busy right now with educational seminars around the 2019 Rules of Golf, they may want to get that over before they turn their attention to another pretty significant change.

I don't think we'll see that. The handicapping system is nowhere near the monstrosity that the Rules of Golf are.

Not in the spring, anyway.

[Aguirre]

On 2/11/2019 at 7:49 AM, iacas said:

For one thing… it’s not finalized.

Well that makes sense.

On 2/11/2019 at 8:29 AM, DaveP043 said:

@Aguirre  The Standard Scratch Score is adjusted based on scores recorded on a specific day. 

I'm really interested to see how this will work. It obviously will do fine at private clubs that have an average and up number of rounds played. Elsewhere, I don't see how. Unless they use a geographic region and assume similar playing conditions.

[iacas]

8 hours ago, Aguirre said:

I'm really interested to see how this will work. It obviously will do fine at private clubs that have an average and up number of rounds played. Elsewhere, I don't see how. Unless they use a geographic region and assume similar playing conditions.

It's going to be per course. One course could be hosting a tournament or be set up really easy one day without affecting the other courses in the area.

If courses don't get enough play (enough scores returned), then their ratings will not change.

[DaveP043]

In following up on @iacas' post in another thread, I took a peek at the Golf Genius website.  The first thing I saw was a link to this:

WHS White Paper.pdf - Google Drive

It includes a reasonably good summary of the 6 handicap systems currently used around the world, as well as a discussion of the World Handicap System which will come into effect for most of us in a little over 7 months.  I didn't see anything really new, but its one of the better summaries I've come across.