The World Handicap System. Is it Good? (Moved from the BUDA thread)

[Carl Johnson]

Is the GHIN handicap system back up yet and in great shape in your area?  Here in N.C. our CGA site is still down (as of 8:51 am, Jan. 7).  However, I am not surprised.

[Erik J. Barzeski]

You have claimed to be a software developer. That is usually the professional path computer science majors choose.

I have in the past and still do develop software (or web apps/sites), but I don't believe I've ever said it was my "chosen profession." Also, computer science is not my only degree in the sciences.

If you have something about the WHS to discuss, please, and by all means.


Back to the topic, here's a post I made on my site that may help some here, too:

The use of par serves two purposes.

• It plays a role in limiting “net double bogey”.
• It helps to “bake in” the difference in playing handicaps from different tees.

I’ll briefly explain both, starting with the second one first.

Baked in Tee Difference
Assume a 5.1 index golfer has the choice to play two tees (or two 5.1 golfers want to play against each other from different tees). A tees are rated 73.4/139. B tees are rated 68.2/124. First let’s assume the par is 72 from both sets of tees. The playing handicap or course handicap (CH) from both tees are:

A: 5.1 * 139/113 + 73.4 - 72 = 7.7 = 8 CH
B: 5.1 * 124/113 + 68.2 - 72 = 1.8 = 2 CH

This is the “big difference” by adding par to the equation… but what it’s really doing is adding the course rating to the equation. The back tees play tougher than par for the scratch golfer, so it makes sense that golfers get more strokes, and vice versa for the shorter tees - they play much easier than par, so we take some strokes away.

This isn’t really different from the old way that you were supposed to handle playing from different tees except that it’s baked in to the actual course handicap. Under the old method, you’d have gotten course handicaps of the same thing— 6 — because (5.1 * 139/113) and (5.1 * 124/113) both equal 6, but then you’d have to figure out the difference between the course rating: 73.4 - 68.2 = 5 strokes someone playing from B would have to give someone playing from A.

Why is the difference now six shots when it used to be five? Because the old formula rounded twice (one rounds down to a 6, the other rounds up to 6), while the new way just rounds the one time after the course rating is included.

Again, this makes sense. Why should a 5.1 index get six strokes when they’re playing a 73.4/139 set of tees and the same six strokes when they’re playing a 68.2/125 set of tees? The use of par in this case just “bakes in” the course rating and makes it easier for players, tournament directors, etc. to conduct a fair match from different tees.

Let's assume a 1.0 plays a 5.2 and wants to play from different tees with the same par:

Old Method:
1.0 * 139/113 = 1 CH
5.2 * 124/113 = 6 CH, minus the 5 shots difference in course rating… the golfers would play each other straight up.

WHS Method:
1.0 * 139/113 + 73.4 - 72 = 3 CH
5.2 * 124/113 + 68.2 - 72 = 2 CH, so the 5.2 has to give the 1.0 a stroke.

(Again, this is because the rounding is done just once, instead of twice.) The 1.0 is only about 4 shots worse (5.2 to 1.0), and yet he’s playing a course that’s over 5 shots easier (73.4 to 68.2). So the 5.2 giving the 1.0 a shot makes sense, and it’s baked in: you just have to look at your playing handicap for those tees and away you go.

Application of NDB
The application of NDB (net double bogey) also relies on par.

I’ll keep this section fairly simple, as I’ve seen a LOT of math from the USGA, and it just works out pretty darn well overall. You can come up with examples left and right, but basically… if you’re playing an easier set of tees, you’re limited with the use of par in posting higher scores a bit more so than you used to be under the old system.

Under the old system a 13 index golfer might be a 14 from the back tees and a 12 from the front tees. People saw this as an advantage, but it really just meant that you could post almost the same score from one set of tees as you could from another, despite the forward set of tees often being 5, 6, or 7 shots easier, inflating his handicap much more quickly from the front tees.

With NDB, he can’t inflate his handicap as quickly. Let’s use the same A and B tees with a 5.1 index, and assume the par for each set of tees is 72 and 69.

Old:
A: 5.1 * 139/113 = 6 CH
B: 5.1 * 124/113 = 6 CH

Because the course rating of the B tees is 68.2, a golfer looking to inflate his handicap would definitely play the B tees. He could post the same exact score despite the course playing about five shots easier (or three shots easier, if you use par instead of the course rating).

New:
A: 5.1 * 139/113 + 73.4 - 72 = 8 CH
B: 5.1 * 125/113 + 68.2 - 69 = 5 CH

Under the new scenario, we’ve already shaved three strokes off just from the course handicap/playing handicap for that player, but an additional three shots comes off from the par because we’ve lost perhaps three par fives that become par fours (par 72 -> par 69) for the golfer. This change costs him six shots off his potential score, resulting in about the same differential if the golfer has a “bad day”:

A: (86 - 73.4) * 113/139 = 10.2 differential
B: (80 - 68.2) * 113/124 = 10.8 differential
B: (86 - 68.2) * 113/124 = 16.2 differential - OLD WAY

Here the golfer “saves” those six strokes - since “Net Double Bogey” is tied to par - and shoots about the same differential. The latter is still a bit higher, but only half a shot and nowhere near as high as the score he could have posted with the six strokes (three from the par, three from the playing handicap) added back in.

(Generally speaking, though… the NDB stuff doesn’t matter too much. Tons of studies the USGA has conducted show that the odds of a round that has ESC or NDB applied almost never actually figure into the 8 rounds that count, and the small percentage of the time they do, it’s going to amount to a small difference only.)

I hope that helps to explain things a little. It can be confusing, but the use of par is actually pretty elegant. It “bakes in” the handicaps when playing from different tees when par is the same (see also 6.2 of the handicapping manual). Few understood that they had to make this second adjustment before - look at how silly it was that two 5.2 indexes playing from A and B tees to both have 6 course handicaps. Golfers often didn’t know to subtract the difference in the course ratings, but the new system bakes that in and prints it right on the sheet you’ll read in the pro shop or locker room.

Then, for the application of NDB, the use of par (and the course rating) result in a wiser, more just application of controlling bad holes.

[Erik J. Barzeski]

Is the GHIN handicap system back up yet and in great shape in your area?  Here in N.C. our CGA site is still down (as of 8:51 am, Jan. 7).  However, I am not surprised.

It is up for me (and has been since yesterday), but we're out of season, and I doubt that a bunch of western PA golfers are trying to get on and post scores and such. Those in the year-round posting areas are getting hit a bit harder.

I've seen a few examples of the earlier thing where the "par" is accidentally set to 144 or 137 or something, too. Many state/regional golf associations don't have a lot of staff, and honestly, they may have put some of this off a little too long. Or courses were slow to send in scorecards, or what-have-you. The folks I know are working very hard to get things squared away quickly, but I'm sure the USGA is a little disappointed with the bumpy takeoff. Small consolation that the bumps are from the tech, and not the actual process or the WHS or whatever.

[Carl Johnson]

Is the GHIN handicap system back up yet and in great shape in your area?  Here in N.C. our CGA site is still down (as of 8:51 am, Jan. 7).  However, I am not surprised.

Message received from our golf club--10:15 a.m.


"Good morning-[/size]"We just received a communication from the Carolinas Golf Association that they are still experiencing issues with the changeover. The course ratings, par values and stroke index allocations are not being picked up correctly across the board. This means if you try and post a score you may not find the correct information to do so. "They have asked us to inform all members to not post scores today. GHIN is working on the problems and we will send another email out when everything is corrected."


However, you could not post even if you tried to.  The site is not accessible.  From my standpoint, I hope they take care to get it right the first time, however long it takes.  Time is not of the essence.

[Garland Bayley]

In his first paragraph, he points out that par is unnecessary for a handicap system. I hope there are no USGA members that would take issue with that.

That mis-states or fails to understand what "par" is being used for. As I've shown, it's just a number (except that if it was 54, net double bogey would have been goofy, of course). Par + NDB leads to accurate handicapping.

Really Erik?
You basically spent your golfing career with a handicap system that had no use for par. And, now you are challenging the above statement? Clearly brings reading comprehension into question.

[Erik J. Barzeski]

Really Erik?
You basically spent your golfing career with a handicap system that had no use for par. And, now you are challenging the above statement? Clearly brings reading comprehension into question.

Yes, really.

And I didn't disagree with par being unnecessary; I simply said I don't feel he understand how it's being used.

Bunkers are not necessary to build a golf course, but their inclusion can make a good golf course better. Par isn't necessary for a handicap system, but its inclusion — the way the WHS uses it — makes the new method better, IMO.

Also, he doesn't say anything about par in the first paragraph:

I love the USGA. I was a charter member of the USGA Handicap Research Team. I created the USGA Course Rating System in 1976 and later the Slope Rating System to make handicaps more reliable and portable. I gave up a great career in the Navy to join the USGA staff in 1981 as its first Director of Handicapping. Over the next 16 years, I helped establish the use of Slope Rating throughout the United States and many other countries. My nickname even became “The Pope of Slope.”

Or the second or third.

The fourth mentions "par" but doesn't talk about it being unnecessary.

The fifth paragraph (sixth? I may have lost count, but it's not the first) says:

Prior to the WHS, par was not a factor in the USGA system of course handicap calculation—nor need it have been. A golfer’s Handicap Index was adjusted around Course Rating to create a course handicap. At the risk of getting wonky, here was the old formula:

He says "nor need it have been" as in the past tense, he doesn't say it's unnecessary forever or by rule or anything. He even notes in a later paragraph that par has been used in other handicapping systems:

This par-based adjustment (Course Rating minus Par) has been part of handicap systems in a handful of countries but for specific reasons. It originated in Sweden and Australia, where golf is often played using a Stableford format (based around scores in relation to par on each hole), and points, not strokes, are posted for handicap purposes. It made sense then that their formulas would include a step to add par to the equation.

Finally he says this:

What does not make sense, though, is applying the par adjustment throughout the rest of the world, in particular to the U.S., where it creates an assortment of issues.

I disagree that "it does not make sense," and I've shared my opinion on why it does make sense, and what it does.

[David Harshbarger]

Really Erik?
You basically spent your golfing career with a handicap system that had no use for par. And, now you are challenging the above statement? Clearly brings reading comprehension into question.

Yes, really.

And I didn't disagree with par being unnecessary; I simply said I don't feel he understand how it's being used.

Bunkers are not necessary to build a golf course, but their inclusion can make a good golf course better. Par isn't necessary for a handicap system, but its inclusion — the way the WHS uses it — makes the new method better, IMO.

Combing par and rating (by tees) makes calculating the shots given/received work.  That's the point of the handicapping system in the first place, to make competition between players of different skills and abilities equitable (note, that's not the same as "fair") and giving/receiving shots is a pretty clever way to make competition equitable.

For a handicapping system to work in practice that means spoon feeding the numbers and hiding the math, which this method does.

[Rob Marshall]

From Alex Myers Golf Magazine


The World Handicap System: The new system that’s going into affect and will put most of the world on the same system makes a lot of sense. I applaud such changes as attempting to factor in conditions and updating daily so there isn’t as much luck as to when your handicap is calculated ahead of your big event. I also like the net double bogey max rule for everyone. It never made sense to me that different players could take different max scores. However. . .

WE'RE SELLING
The World Handicap System: There are still some problems, starting with the system counting even fewer rounds. I’m not a math major, but the fewer the rounds that count, the smaller the sampler size and the less accurate you get. I thought they’d go the other way with that. Also, as Dean Knuth points out, the new extra calculation to adjust course handicaps to par defies logic (since course rating already factors par into its equation) and makes this process even more confusing. In related news, I hate course handicaps because I always feel like I’m giving everyone on my golf trip too many strokes. I’m calling for a course handicap revolution! Get rid of them altogether!

[Garland Bayley]

Really Erik?
You basically spent your golfing career with a handicap system that had no use for par. And, now you are challenging the above statement? Clearly brings reading comprehension into question.

...
The fifth paragraph (sixth? I may have lost count, but it's not the first)

My bad. With the insertion of advertising segments into the middle of an article, I got started on the 5th paragraph, instead of the first. So I mislabeled the 5th paragraph as the first, but stating the next bit gave the formulas should have pretty well established where I was starting. Sorry for the confusion.

 says:

Prior to the WHS, par was not a factor in the USGA system of course handicap calculation—nor need it have been. A golfer’s Handicap Index was adjusted around Course Rating to create a course handicap, At the risk of getting wonky, here was the old formula:

He says "nor need it have been" as in the past tense, he doesn't say it's unnecessary forever or by rule or anything. He even notes in a later paragraph that par has been used in other handicapping systems:
...

Just above you wrote, "He says "nor need it have been" as in the past tense," Exactly, it was unnecessary in handicapping. The paragraph simply points out there is no need for par in handicapping. I suggested no USGA member could reasonably argue with that, but yet you argue about it. You make a spurious claim that  "That mis-states or fails to understand what "par" is being used for". It is spurious because there was no statement about what par was being used for. The question of reading comprehension comes from your interjection of issues not even mentioned. If that came about because I got the paragraph numbers wrong I apologize.

[Garland Bayley]

...
Combing par and rating (by tees) makes calculating the shots given/received work. 
 
The handicap system you used in the past without par did not work?

That's the point of the handicapping system in the first place, to make competition between players of different skills and abilities equitable
That's right brother! Now let's not pollute it with par.
(note, that's not the same as "fair") and giving/receiving shots is a pretty clever way to make competition equitable.
Not sure what the need is for distinguishing synonyms equitable and fair here is. Just out of curiosity, why did you introduce the word fair here?

For a handicapping system to work in practice that means spoon feeding the numbers and hiding the math, which this method does.
 
How much math did you have to do to use the old system?

[Erik J. Barzeski]

Garland, I'm still waiting for you to present an argument of your own. Now you're just recapping the discussion. IMO, the addition of par to the handicap system made the handicap system better. It helps with Net Double Bogey and it helps to "bake in" the differential when playing from different tees. You've not said a word to refute that. So, until such time as that changes, I rest my case.

[Garland Bayley]

...
As congenially as possible, please ask yourself: what have you done but blindly support Dean's article here?
...

Let's see how blind I have been. Below I provide a quote from the thread where I analyzed Dr. Knuth's article. I have excerpted my commentary on it to see how blindly I follow Dr. Knuth. What I earlier wrote is highlighted in red. My current commentary on whether it is blindly following is in purple.

...
The crux of the matter comes down to the next paragraph where he points out that course rating is a far more accurate measure of course difficulty, and notes that others, including Tom Doak, have adopted an "Abandon Par" ideology. Then comes the crux, "calculating a handicap around a less reliable measure of difficulty inherently makes for a less equitable system." Although, I did not provide a personal commentary on this paragraph, I have in other posts made it clear that I agree with it, and have provided arguments that Knuth is right in calling it "less equitable." My arguments used Erik's calculations. So who am I blindly following?
...
In the next paragraph he correctly points out that the new formula produces a wide range of course handicaps for a player as he moves from the set of tees at one end of the spectrum to the set of tees at the other end of the spectrum. He calls this an "imperfect “over-spreading” of the course handicaps." My interpretation of this is that you are now adjusting to an imperfect measurement of the difficulty of the hole, par. Other interpretations are possible. Not exactly blind following.
...

I am confident that he would get those calculations correct. As apparently Erik is too.

...
They show the range of playing handicaps the players might get from the back to the front tees. So?
...

Guess that makes us both blind followers on this one.
...

In the next paragraph, he points out that when the course rating differs by .5 from from the par, half of the players will get their course handicap changed while the other half will not. Can anyone challenge that? I think not.Erik does challenge this so I guess I am blindly following here. I will have to address Erik's challenge in another post.

In the next paragraph, he points out that the USGA says the new system is "more intuitive". As I posted earlier, I find this to be a benefit, because unknowing players think the old handicap adjusts to par, not course rating, and I have to correct them. Seems I am agreeing with the USGA here. GASP

In the next paragraph he writes, "Golfers competing from more forward tees will be receiving fewer strokes than is truly equitable." This is what I will have to study more to satisfy myself either way. Blindly following? I think not.

The next USGA argument given in the next paragraph is the old system required a handicap adjustment for players playing from different tees. IMO Dr. Knuth adequately counters this argument. My counter argument is different than Dr. Knuth's, so is that blind?
...

The next things addressed by Dr. Knuth from where I left off above are 1) daily handicap updates, 2) Playing Conditions Calculation, 3) manual application of net double bogey. I haven't seen any noticeable (to me) criticism of these points on this thread so I will not address them now. No basis here for saying I am blindly following.
...

Hopefully I covered everything that could be blind or not.

So Erik, is you blind follower accusation hyperbole, or are you experiencing a reading comprehension problem?

[David Harshbarger]

...
Combing par and rating (by tees) makes calculating the shots given/received work. 
 
The handicap system you used in the past without par did not work?

That's the point of the handicapping system in the first place, to make competition between players of different skills and abilities equitable
That's right brother! Now let's not pollute it with par.
(note, that's not the same as "fair") and giving/receiving shots is a pretty clever way to make competition equitable.
Not sure what the need is for distinguishing synonyms equitable and fair here is. Just out of curiosity, why did you introduce the word fair here?

For a handicapping system to work in practice that means spoon feeding the numbers and hiding the math, which this method does.
 
How much math did you have to do to use the old system?

At my course we use the old system.  What I like about the new approach is that it incorporates the next step in practical application of handicaps: generating a course handicap for the tees each player is playing that day. 


Now, that's not the primary use case: two blokes playing against each other from the same tees.  The old approach was fine there (perceived to be fine by the players at least). But the new approach doesn't negatively impact that.


At my course we were stumped when a.) we had mixed gender groups or b.) seniors who established handicaps from the men's tees moved up to the senior tees for competitions.  The course has different par for the women, and multiple holes have different par for them to boot. The not-yet-seniors amongst us always felt that the seniors were getting away with something taking their handicaps forward to shorter tees.


The new approach appears to address both of these, which is a benefit to our club.


Equitable, in how I use the term, is a bit more squishy than fair.  I think of equitable as "fair-enough".  M-W may not agree with me :-)


As far as the math we used to do, well that's the root of the problem, we didn't do enough! 


At the end of the day, any system like this has an element of arbitrariness to it.  There's a simple fix to that: compete at scratch!


Harvey Pennick wrote something that stuck me re: the two primary country club sports golf and tennis.  In tennis, it's very unsatisfying to play an opponent either much better or much worse than you. If you are the better player there's no challenge.  If you are the lesser player, there's no chance.  But thanks to handicaps, in golf, we can all enjoy a competition where better and lesser players have a satisfying competition. 


If that system is easier to engage with, and the system is seen as fair-enough, the goal is met.  The new system seems to meet that objective and does so in a some real-life conditions that we struggled with.

[Erik J. Barzeski]

So Erik, is you blind follower accusation hyperbole, or are you experiencing a reading comprehension problem?

Garland, I disagree with you (and Dean) that the new WHS is "flawed." I called you out for having "bad math" earlier, which is a matter of fact, and I realize I could have done so in a more genteel way. Surely. But particularly the last two or three days I've attempted to get back to the actual topic - the WHS and specifically these supposed "flaws" - and to avoid anything personal or overtly negative or anything like that, and now, clearly, I ask that you do the same. Failing that, there's no value to be had here from my side.

In my last post or however many, I'm saying that from my perspective you're not offering an actual defense of Dean's article except to say "he's the expert" and to declare agreement with what he wrote. I'm saying that I've offered opinions and calculations and examples that show why I disagree with Dean's opinions and even his understanding as to why "par" (really the course rating) is more involved in the WHS formulas. I've shown examples why I disagree with Dean's opinions, examples that show why I think the WHS system is better than the old system.

have provided arguments that Knuth is right in calling it "less equitable."

Ignoring the fact that opinions can't really be "right" or "wrong" (I feel the idea of what is "equitable" is more opinion here than fact, given that the whole thing is an "invention" rather than a natural truth), I don't believe Dean offers evidence that the WHS is "less equitable"… if only because the WHS often arrives at the same results as the old system when applied correctly for players from different tees. If he's talking about the "playing handicap" and how a 12 might be a 6 now for the playing handicap only…

The only real change is how ESC and NDB interact. A 9.3 index player playing from the front tees (let's say 68.2/124, par 72) used to have a course handicap of (9.3 * 124/113) = 10 CH, which meant he could take a 7 on any hole. Now he has a course handicap of (9.3 * 124/113 + 68.2 - 72) = 6 CH, which means he can take gross triples on six holes and gross doubles on the other 12.

How is it "less equitable"? If that 9 shoots 78, the math is still the same for his differential: (78 - 68.2) * 113/124 = 8.9 differential. This is unchanged and does not involve par. Par is not involved in the determination of the player's handicap beyond the NDB, and when NDB is involved, I find the new system more equitable, more correct, more "fair."

I find it more "fair" and equitable and correct because again, if you're playing a 68.2-rated course that's a par 72, you're probably playing a few holes similar to a "440-yard par five" or something in there, so it makes sense to me that you'd lose a few of your gross triples (when your 10 CH in 2019 becomes a 6 in 2020).

My interpretation of this is that you are now adjusting to an imperfect measurement of the difficulty of the hole, par. Other interpretations are possible.

This is one of the points where I feel Dean is misunderstand how "par" is being used. They're not using par as the "imperfect measure." They're using the course rating.

6.8 + (73.4 - 68.2) = 6.8 + (73.4 - 72) - (68.2 - 72) = 12

The math works out the same - they're using the course rating.

In the next paragraph, he points out that when the course rating differs by .5 from from the par, half of the players will get their course handicap changed while the other half will not. Can anyone challenge that? I think not.Erik does challenge this so I guess I am blindly following here. I will have to address Erik's challenge in another post.

I did challenge Dean's point that the 0.5 thing is going to result in rounding where one player occasionally gets a stroke while another does not… by pointing out that such thing existed in 2019, too, and will always exist so long as we're rounding.

In the WHS, for example, we round only once, IMO making it MORE accurate than before when we would round once or twice depending on whether golfers were playing different tees or not.

I addressed this before. Of course I don't challenge the math itself, I challenge whether this is a "flaw." It is not, IMO, and I've already said why.

Again (refactored):

IMO, the addition of "par" (and course rating) to the handicap system made the handicap system better. It plays a role in two things only:

• It helps with Net Double Bogey and
• It helps to "bake in" the differential when playing from different tees.

The rest of the WHS remains almost the same. You calculate your differential the same way. You count only 8 of 20 instead of 10 of 20, but you also don't multiply by 0.96.

At the end of the day, any system like this has an element of arbitrariness to it.  There's a simple fix to that: compete at scratch!

Agree. That's why even what's "equitable" is more opinion than fact, because the entire course rating system is based on some decisions we made and continue to make about how much bunkers matter: a bunker that's 2.9 feet is rated differently than a bunker that is 3.0 feet deep, a scratch golfer was determined to be able to hit the ball 250+220, etc.

[Garland Bayley]

...
In my last post or however many, I'm saying that from my perspective you're not offering an actual defense of Dean's article except to say "he's the expert" and to declare agreement with what he wrote.
Here we go with the reading comprehension problem again. 
I'm saying that I've offered opinions and calculations and examples that show why I disagree with Dean's opinions and even his understanding as to why "par" (really the course rating) is more involved in the WHS formulas.
Dean's facts are not opinions. His facts are correct. Your "facts" are misapplied.
I've shown examples why I disagree with Dean's opinions, examples that show why I think the WHS system is better than the old system.
In the following, I insert part of a previous post that shows my demonstration of Dr. Knuth's facts (using your data) that shows the inequity of the new system.

...

...
Old
17.8 * 136/113 = 21.42 = 21 CH
17.9 * 136/113 = 21.54 = 22 CH
18.6 * 136/113 = 22.38 = 22 CH
18.7 * 136/113 = 22.50 = 23 CH

Range is 0.7 strokes - 17.9 to 18.6.

New
17.6 * 136/113 + 71.3 - 71 = 21.48 = 21 CH
17.7 * 136/113 + 71.3 - 71 = 21.60 = 22 CH
17.9 * 136/113 + 71.3 - 71 = 21.84 = 22 CH
18.4 * 136/113 + 71.3 - 71 = 22.45 = 22 CH
18.5 * 136/113 + 71.3 - 71 = 22.57 = 23 CH

Range is 0.7 strokes - 17.7 to 18.4.

The range shifts slightly (because of the 71.3 - 71) but it's still the same width, the same 0.7 (which is 8 tenths, as the endpoints are inclusive).[/font]

As Erik points out the handicap index ranges to obtain the the same course handicap are
17.9 to 18.6 in the old system
17.7 to 18.4 in the new system

When using the system most closely tied to the ratings (the old system) a player whose index is 18.5, or 18.6 will play with the same Course handicap as the players whose handicaps are 17.9 to 18.4.
However, when players with 18.5 or 18.6 course handicaps play in a medal play tournament under the new system, they will have an advantage of one stroke over the players with 17.9 to 18.4 handicap indexes. This is how the par handicap system has moved away from being as accurate as the course and slope rating system. You are shifting the calculations away from the most accurate system to one that approximates it some, but does not match its accuracy.

So Dean's and my facts show what was equitable. Players with handicap indexes of 17.9, 18.0, 18.1, and 18.2 are treated equitably to those with handicap indexes of 18.4, 18.5, 18.6, and 18.7. I.e., they receive the same course handicap as 18.3. These handicap indexes are all calculated from the course rating, and the slope rating and the players scores. So the players scores that average closest to 18.3 (the index for which the scoring averages are closest to), are all grouped from 17.9 to 18.6.

When you calculate the course handicap by using par, you end up with a range of handicap indexes that is the same size range as that of the old systems range as Erik has demonstrated. However, Erik's claim that that means the new system is as equitable as the old system is a mistake. Those with the handicap index 18.3 would play those someone with a handicap index of 17.7 straight up. They would have to give a stroke to someone with handicap index 17.9. However, the scoring average of the person with the 17.7 handicap index is significantly more removed from the scoring average of the person with handicap index of 18.3 than the scoring average of someone with the handicap index 18.6 is removed from the scoring average average of the person with the handicap index of 18.3. Therefore, the person with the handicap index of 18.3 should not have to play someone with the handicap index of 17.7 as an equal while he has to give a stroke to the person with the handicap index of 18.6 who's scoring average is closer.

It is not equitable to give strokes to someone who's scoring average is closer to yours while not giving strokes to someone who's scoring average is farther from yours. Dr. Knuth and I simply figured that would be obvious from our previous statements. Therefore, our presentations were perhaps too pithy.
...

[Erik J. Barzeski]

Garland, there's nothing magical about 18.3, and the range of handicaps where players played straight up shifted in the old system, too.

As I said even in the part you quoted, in the WHS determination of course handicap, the range shifts slightly,so 18.2/18.3 is no longer the middle, but the size of the range stays the same. The range shifted in the old system too:

Different Course, Old System:
17.5: 17.5 * 119/113 = 18.4 = 18 CH
17.6: 17.6 * 119/113 = 18.5 = 19 CH
18.4: 18.4 * 119/113 = 19.4 = 19 CH
18.5: 18.5 * 119/113 = 19.5 = 20 CH

In this example, not only does the range shift (from 17.9 to 17.6 on the low end, and from 18.6 to 18.4 on the high end), but the size of the range changes. All under the old system.

Another Different Course:

18.0: 18.0 * 153/113 = 24.4 = 24 CH
18.1: 18.1 * 153/113 = 24.5 = 25 CH
18.7: 18.7 * 153/113 = 25.3 = 25 CH
18.8: 18.8 * 153/113 = 25.5 = 26 CH

Once again, not only did the range shift but it changes size too: now the only players playing straight up are the 18.1 to 18.7 players. The size changes AND the range shifts.

Old Calculation (136 slope):
17.8 = 21 CH
17.9 = 22 CH
18.6 = 22 CH
18.7 = 23 CH   range is 0.8 inclusive from 17.9 to 18.6

New Calculation (136/71.3/71):
17.6 = 21 CH
17.7 = 22 CH
18.4 = 22 CH
18.5 = 23 CH   range is 0.8 inclusive from 17.7 to 18.4

Old Calculation (119 slope):
17.5 = 18 CH
17.6 = 19 CH
18.4 = 19 CH
18.5 = 20 CH   range is 0.9 inclusive from 17.6 to 18.4

Old Calculation (153 slope):
18.0 = 24 CH
18.1 = 24 CH
18.7 = 24 CH
18.8 = 25 CH   range is 0.7 inclusive from 18.1 to 18.7


It's fine that you quoted my old post and replied to it, but I changed it within minutes to say "Rewriting" and this is the rewrite.

[Garland Bayley]

...
At my course we use the old system.  What I like about the new approach is that it incorporates the next step in practical application of handicaps: generating a course handicap for the tees each player is playing that day. 

Are you sure it generates a course handicap for the tees each player is playing that day? People have been reporting on this thread that they are getting a new handicap index from the new system. It would seem they will still have to go to a table to get a course handicap for the tees they are playing. In the old system, the club could print out the course handicaps for each player about every two weeks. It would seem likely that the club would now have to print out course handicaps for each player everyday, as their handicap index is to be updated after each round they post.

Now, that's not the primary use case: two blokes playing against each other from the same tees.  The old approach was fine there (perceived to be fine by the players at least). But the new approach doesn't negatively impact that.

As demonstrated exhaustively in my post answering Erik above, the new approach gives less equitable handicaps. I would say that is a negative impact.

At my course we were stumped when a.) we had mixed gender groups or b.) seniors who established handicaps from the men's tees moved up to the senior tees for competitions.  The course has different par for the women, and multiple holes have different par for them to boot. The not-yet-seniors amongst us always felt that the seniors were getting away with something taking their handicaps forward to shorter tees.

The USGA (or their regional assocations) could have eliminated this difficulty by simply providing an app that could do all these calculations automatically.

The new approach appears to address both of these, which is a benefit to our club.

Which would you rather have? An app that could give you the correct adjustments automatically when asked, or a table to look up you course handicap that does not treat your scoring average equitably.

Equitable, in how I use the term, is a bit more squishy than fair.  I think of equitable as "fair-enough".  M-W may not agree with me :-)

We are the opposite on that. I think of fair as more squishy than equitable. I think of equitable as "eminently fair".

As far as the math we used to do, well that's the root of the problem, we didn't do enough! 

And, your handicap provider should have provided apps that took away the need for math.

At the end of the day, any system like this has an element of arbitrariness to it.  There's a simple fix to that: compete at scratch!

Harvey Pennick disagrees with you.

Harvey Pennick wrote something that stuck me re: the two primary country club sports golf and tennis.  In tennis, it's very unsatisfying to play an opponent either much better or much worse than you. If you are the better player there's no challenge.  If you are the lesser player, there's no chance.  But thanks to handicaps, in golf, we can all enjoy a competition where better and lesser players have a satisfying competition. 


If that system is easier to engage with, and the system is seen as fair-enough, the goal is met.  The new system seems to meet that objective and does so in a some real-life conditions that we struggled with.

They didn't have to corrupt the old system to meet that goal.

[Garland Bayley]

Okay, so, you're still choosing to go that route. Rather than discussing the actual topic, you'd rather just continue to behave like that, Garland.

Cool. Whatever.

P.S. Seriously, though, please re-read your post, man, and think about what you wrote. There's nothing magic about 18.3

There is something magic about 18.3. It is the handicap index closest to the scoring average for the players that should be grouped together. When you go to the new system, 18.3 will still be the closest to the scoring average! Scoring averages don't change just because the formula for course handicap changes. The new course handicap moves farther away from the scoring average as the course ratings move away from whole numbers. Course ratings are a whole numbers 1/10 of the time. Par is a whole number 100% of the time. If you use the less accurate par number in the calculation, you will get less accurate results.

on this fictitious golf course.

i believe we are still using numbers from Windsong Golf Club, Jason Topp's club. So not fictitious.

As I said even in the part you quoted, the range shifts slightly, so 18.3 is no longer the middle value.

Again, that is where your reasoning goes awry. It is not the middle value that is of importance. It is the scoring average that is of importance. 18.3 corresponds to the scoring average.

The old way is 17.9 to 18.6, the WHS way is 17.7 to 18.4, but the size of the range is still the same. Play a course with a slightly different slope - under the new OR the old way - and the ranges would also shift under either system. By using par (and the course rating) the range shifts, but it doesn't change its size: that's a function of the slope, and the slope was used in both the old and the new systems.

True statisticians like Dr. Knuth could care less about your range shift being the same size. They care about a statistic like average (or mean as they are wont to call it)! He has pointed out to you that your range shift corrupts the average. I am sorry to report that you have failed Dr. Knuth's statistics class.

[Erik J. Barzeski]

There is something magic about 18.3. It is the handicap index closest to the scoring average for the players that should be grouped together.

Sez who? Huh? Who says these players "should be grouped together"? Scoring average for what? And when you're counting 8 or 10 out of 20 rounds, the scoring average of those 20 rounds is not going to be 18.3 (differentials) anyway.

I showed above how 18.3 isn't the "middle value" for players playing straight up on other courses under the OLD system.

Course ratings are a whole numbers 1/10 of the time. Par is a whole number 100% of the time. If you use the less accurate par number in the calculation, you will get less accurate results.

Garland, the old system didn't even use course ratings in determining the handicap, and when you subtract a whole number from a course rating with decimals… you get a decimal value.

i believe we are still using numbers from Windsong Golf Club, Jason Topp's club. So not fictitious.

By "fictitious" I meant a course with that particular course rating so 18.3 worked out to be in the middle.

Again, that is where your reasoning goes awry. It is not the middle value that is of importance. It is the scoring average that is of importance. 18.3 corresponds to the scoring average.

The scoring average of what?

And again, on other courses, under the OLD system, 18.3 was not the middle of the range of golfers playing straight up.

True statisticians like Dr. Knuth could care less about your range shift being the same size. They care about a statistic like average (or mean as they are wont to call it)! He has pointed out to you that your range shift corrupts the average. I am sorry to report that you have failed Dr. Knuth's statistics class.

The number "18.3" does not even appear in the Knuth article. There's nothing inherently magical about 18.3, and even if there was, if that number shifts slightly under the new system… so what? Because… again… it shifted under the old system depending on the course you were playing.

[Erik J. Barzeski]

True statisticians like Dr. Knuth could care less about your range shift being the same size. They care about a statistic like average (or mean as they are wont to call it)! He has pointed out to you that your range shift corrupts the average. I am sorry to report that you have failed Dr. Knuth's statistics class.

Garland, not only does 18.3 not appear in the article, but the word "average" appears only twice, and both are here in this paragraph:

I’ve explored a large sample size of courses in Southern California and found a male golfer with a 14.1 Handicap Index under the old USGA system has a range of course handicaps from 12 to 18 with an average course handicap of 15. Under the WHS, due to the par adjustment, his range now varies from -1 to 22 with an average course handicap of 11.6, effectively giving him more than three shots less in the process.

Those two times are the only times the word "average" is used.

What's more, let's take a look at this 14.1 index golfer who on December 31 would have gotten 12 or 18 shots from the forward or back tees and who, on January 1, got -1 to 22 strokes.

• If he plays the back tees, on December 31 he gets only 18 shots, and on January 1, he gets 22! He gains four shots! Dean focused only on the loss to the average number of strokes he received, but here's a situation where the golfer gains four shots versus the old system.
• That average, of course, of 11.6 includes tees with a course rating of around 57.0. Maybe it's just me, but I see that as a flaw of the OLD system, that a 14 should get 12 shots playing tees rated 57.0.

Dean also says:

(An aside: Scratch golfers are no longer 0 handicaps everywhere. They could be playing anywhere from a plus 12 to a 6 handicap.)

They're still scratch golfers. They still have 0.0 indexes (or very close to it). A scratch golfer in 2019 had to shoot 74 to get a 0 differential on a 74.0-rated course, and that's true in 2020 as well. He'll have a course handicap (assuming par is 72) of 2 in 2020, but that again makes sense to me. Just like a scratch golfer had to shoot 68 on a 68.0-rated course in 2019 to get a 0 differential. Still true today, though they'll be a -4 course handicap if the par is 72.

At the end of the, too, par is not used in determining your differential for the day. That formula remains the same. So whether the scratch golfer shoots 74 on the first course in 2019 or 2020, the differential is 0. If he shoots 68 on the second course, it's 0 again in 2019 and 2020. That math is unchanged.

[Garland Bayley]

I thought I would capture this bit of absurdity before Erik has a chance to think it be better if he deleted it. I will let you know later when I have finished modifying this post to explain the errors of his ways.

There is something magic about 18.3. It is the handicap index closest to the scoring average for the players that should be grouped together.

Sez who? Huh? Who says these players "should be grouped together"?


The USGA Handicap Reference Manual valid through 2019 says players whose handicap index is from 17.9 to 18.6 on a course with 136 slope have course handicap 22. They are grouped together by their common course handicap!
For readers that aren't familiar with the Handicap manuals
The USGA Handicap Manual valid through 2019 says
Handicap Differential = (Adjusted Gross Score - USGA Course Rating) x 113 / Slope Rating
The Handicap Index is calculated by taking 96 percent of the average of the best Handicap Differential(s) (2019)
I could not find a 2020 manual online, but I found a statement of how to calculate the handicap index for 2020.
A handicap index is calculated based on a simple average of the best eight of the most recent
twenty differentials based on “adjusted gross scores”. (2020)


Scoring average for what?

For playing golf 20 times from the Combo 1 tees of Windsong Golf Club

And when you're counting 8 or 10 out of 20 rounds, the scoring average of those 20 rounds is not going to be 18.3 (differentials) anyway.

The scores 91, 92, 93, 93, 94, 94, 95, 95, 97, 98, 98, 98, 99, 99, 99, 99, 100, 100, 100, 101 on the Combo 1 tees produce a handicap index of 18.3 for both systems.

I showed above how 18.3 isn't the "middle value" for players playing straight up on other courses under the OLD system.

It is sad that you don't recognize how specious your demonstration above is. Every range in every handicap table in the old system will have a "middle value" that will correlate to the handicap index for the players shooting the most average scores that produce "middle value"

Course ratings are a whole numbers 1/10 of the time. Par is a whole number 100% of the time. If you use the less accurate par number in the calculation, you will get less accurate results.

Garland, the old system didn't even use course ratings in determining the handicap

Of course they did. The course rating was used to determine the handicap index. Then the course handicap is calculated from the handicap index. SIGH

, and when you subtract a whole number from a course rating with decimals… you get a decimal value.

Wow, it appears you don't even understand significant figures (also called significant digits) in science and math. What you should know from the concept of significant figures is that "when you subtract a whole number from a course rating with decimals"... you get less accuracy.

i believe we are still using numbers from Windsong Golf Club, Jason Topp's club. So not fictitious.

By "fictitious" I meant a course with that particular course rating so 18.3 worked out to be in the middle.

Again, that is where your reasoning goes awry. It is not the middle value that is of importance. It is the scoring average that is of importance. 18.3 corresponds to the scoring average of the most average golfers ending up with a course handicap of 22 there..

The scoring average of what?

The scoring average of players with an 18.3 handicap index.

And again, on other courses, under the OLD system, 18.3 was not the middle of the range of golfers playing straight up.

But, on other courses there will be a middle value, and a set of scores that produce that middle value. Take the data from any one of those courses, and it will also can also be used to disprove what you have been maintaining here.

True statisticians like Dr. Knuth could care less about your range shift being the same size. They care about a statistic like average (or mean as they are wont to call it)! He has pointed out to you that your range shift corrupts the average. I am sorry to report that you have failed Dr. Knuth's statistics class.

The number "18.3" does not even appear in the Knuth article.

Of course it doesn't. He addresses general concepts. Any theoretical statistician would be able to use a variable instead of 18.3, and produce a proof that what you write is wrong. However, that is not necessary, because the inefficacy of what you write can be demonstrated with any single value.

There's nothing inherently magical about 18.3,

The magical thing about 18.3 is that it along with the course, its rating data, and the nature of the handicap system demonstrates the inefficacy of what you write. It is only one of an infinite number of real numbers (which become
a finite number after rounding) that can demonstrate the failure of your arguments. As any good mathematician knows, it only takes one counter example to disprove something.

and even if there was, if that number shifts slightly under the new system… so what?

18.3 doesn't shift. 18.3 is 18.3. The new system shifts away from it by throwing the inaccurate measurement, par, into the calculation, thereby making players of too different ability compete on equal terms, or making players of too similar ability compete on unequal terms.

Because… again… it shifted under the old system depending on the course you were playing.

SIGH, irrelevant because each course, and each handicap range can be used to invalidate your argument. Remember, it only takes one, so there is no need to go there.

[Erik J. Barzeski]

I thought I would capture this bit of absurdity before Erik has a chance to think it be better if he deleted it. I will let you know later when I have finished modifying this post to explain the errors of his ways.

Good luck with that. I'm out.

[Garland Bayley]

I thought I would capture this bit of absurdity before Erik has a chance to think it be better if he deleted it. I will let you know later when I have finished modifying this post to explain the errors of his ways.

Good luck with that. I'm out.

I have update my capture of Erik's post and explained the many fallacies of Erik's post in my update.

[Rob Marshall]

I thought I would capture this bit of absurdity before Erik has a chance to think it be better if he deleted it. I will let you know later when I have finished modifying this post to explain the errors of his ways.

Good luck with that. I'm out.

I have update my capture of Erik's post and explained the many fallacies of Erik's post in my update. And, it looks like Erik has taken his basketball and gone home.

Probably working on his signature......sorry couldn’t resist

[Garland Bayley]

I just got an email from the Oregon Golf Association. My handicap index did not change under the new system. Still the 17.9 I reported earlier in the thread.