Differential vs Course Handicap

[Clemsonfan]

As an analyst by nature, I would like to compare the scores under both systems. It is something we can easily do if we have the data. I actually thought the new system was less fair to those whose game was on the decline - like mine!

Old: Best 10 of last 20 scores with the .96 multiplier. Course handicap excluded course rating and overall par.

New: Best 8/20. Course handicap includes course rating -par.

My understanding is Stableford caps scores at Net double bogey like stroke play. If so, handicap should be slower to rise because you are only using 8 versus 10 scores. If I am missing something, I am curious enough to  want to understand what that may be.

My home course tees that I play are 72.1/154 now. My best score out here is 82. When my game started to decline, my handicap didn’t budge for 13 rounds because of good scores in my first 8! I know I am an anomaly but my handicap has increased almost 80% in the past few years (with only a few rounds this year). For a few months I knew I was losing every bet because my game was nowhere near my handicap.

I suspect I have steamrolled a few nuances but that shouldn’t matter much. When I have modeled this with someone playing the same tees and course, one good round, or return to form, will immediately reduce the handicap by some amount.

[xrayvizhen]

To flog this subject even further, if that's even possible, this article from Golf Monthly just appeared today in one of my news feeds. Written by a golf writer in the UK who I never heard of, he's basically saying that there should be only 3-5 rounds from the most recent 20 that should count towards the average and only competitive rounds should count. He claims the erratic scorers would have less of an advantage than they do now. He makes a lot of references to "club golfers" in the UK being the ones who are mostly dissatisfied.

https://share.google/qmZZBEoJvOxHxJGil 

In my experience with my league where we have golfers with indexes ranging from 5 to 40, looking at the weekly results from the past two years, I can detect no pattern that would substantiate the claim that the current system gives an unfair advantage to either erratic golfers (aren't we all?) or higher handicappers. Apparently though, at least in the UK, this seems to be "a thing."

Edited yesterday at 12:58 AM by xrayvizhen

[Clemsonfan]

9 hours ago, xrayvizhen said:

To flog this subject even further, if that's even possible, this article from Golf Monthly just appeared today in one of my news feeds. Written by a golf writer in the UK who I never heard of, he's basically saying that there should be only 3-5 rounds from the most recent 20 that should count towards the average and only competitive rounds should count. He claims the erratic scorers would have less of an advantage than they do now. He makes a lot of references to "club golfers" in the UK being the ones who are mostly dissatisfied.

https://share.google/qmZZBEoJvOxHxJGil 

In my experience with my league where we have golfers with indexes ranging from 5 to 40, looking at the weekly results from the past two years, I can detect no pattern that would substantiate the claim that the current system gives an unfair advantage to either erratic golfers (aren't we all?) or higher handicappers. Apparently though, at least in the UK, this seems to be "a thing."

I am fascinated by this article. Given so many are upset, I would love to see how the calculations changed for them. In the USA, it likely reduced handicaps, at least for me. In the UK it appears to inflate handicaps but not uniformly? 

[iacas]

2 hours ago, Clemsonfan said:

I am fascinated by this article. Given so many are upset, I would love to see how the calculations changed for them. In the USA, it likely reduced handicaps, at least for me. In the UK it appears to inflate handicaps but not uniformly? 

What change are you talking about? The switch from 10/20 * 0.96 to 8/20 kept handicaps almost exactly where they were. 8/20 instead of 10/20 reduces it, but eliminating 0.96 brought the 8 back up a little. So net… almost nobody saw a change to their index let alone to the number of strokes they got on the course.

[Ty_Webb]

9 hours ago, iacas said:

What change are you talking about? The switch from 10/20 * 0.96 to 8/20 kept handicaps almost exactly where they were. 8/20 instead of 10/20 reduces it, but eliminating 0.96 brought the 8 back up a little. So net… almost nobody saw a change to their index let alone to the number of strokes they got on the course.

I think he meant in the UK. The old system was completely different from the new one. 10/20 x 0.96 vs 8/20 would really only impact very low handicaps I think. The 0.96 serves to increase differentials for plus differentials, where 8/20 vs 10/20 works to lower differentials for all. I don't know many plus golfers who would be upset that their index got lower. A lot of really good players don't even really keep their handicaps up-to-date. They're much more interested in their WAGR rankings which get them entries to certain events.

[iacas]

46 minutes ago, Ty_Webb said:

I think he meant in the UK.

Not the part I was replying to:

12 hours ago, Clemsonfan said:

In the USA, it likely reduced handicaps, at least for me.

Handicaps did not go down much (like 0.14 on average IIRC?) when we went from 10/20*0.96 to 8/20. And a good chunk of that was from the +s.

[Clemsonfan]

13 hours ago, Ty_Webb said:

I think he meant in the UK. The old system was completely different from the new one. 10/20 x 0.96 vs 8/20 would really only impact very low handicaps I think. The 0.96 serves to increase differentials for plus differentials, where 8/20 vs 10/20 works to lower differentials for all. I don't know many plus golfers who would be upset that their index got lower. A lot of really good players don't even really keep their handicaps up-to-date. They're much more interested in their WAGR rankings which get them entries to certain events.

You’re correct. I was referring to the change in the UK. The USA change was modest. Would love too see a UK comparison of the two methods to truly understand the variances.

22 hours ago, iacas said:

What change are you talking about? The switch from 10/20 * 0.96 to 8/20 kept handicaps almost exactly where they were. 8/20 instead of 10/20 reduces it, but eliminating 0.96 brought the 8 back up a little. So net… almost nobody saw a change to their index let alone to the number of strokes they got on the course.

The change in the UK calculation that the OP raised. In the USA, I haven’t heard any complaints. I can’t understand why the UK is upset without the data to support the complaints.

[Ty_Webb]

On 12/7/2025 at 5:29 AM, Clemsonfan said:

I am fascinated by this article. Given so many are upset, I would love to see how the calculations changed for them. In the USA, it likely reduced handicaps, at least for me. In the UK it appears to inflate handicaps but not uniformly? 

In the UK, it will inflate your handicap if you were better, but are getting worse or have got worse. If you are improving then it will probably lower it if you're a lower handicap and have little impact if you're a higher handicap. 

The old UK system was like this (spoilered since it's kind of long and not entirely on topic):

Spoiler

You had originally 4 "categories", although they did eventually make it 5. Category 1 was 5.4 handicap or lower. Category 2 was 5.5 through 11.4. Category 3 was 11.5 through 19.4. Category 4 was 19.5 or above. 28.4 was the highest possible for men (I think 36.4 for women). They did then introduce Category 5, which was 28.5 up to 36.4 for men and 36.5 up to 45.4 for women.

Handicaps would only change for competition rounds. Your score was your gross score minus the "Standard Scratch Score" or "SSS" - SSS is analogous to course rating in the US. If that was lower than your handicap, then your handicap would be reduced by 0.1 times your category number for each stroke better than your handicap. So if you're a 22.5 and you shoot 20 over, you are 3 under your handicap (22.5 rounds to 23). 3 x 0.4 is 1.2, so your new handicap would be 21.3. If your handicap flips categories in the middle of an adjustment then the adjustment changes in line, so if you're a 20.4 and you shoot 15 over, you're 5 under your handicap. Since you're category 4, that might seem like it should be 5 x 0.4 = 2.0, which would make you 18.4, but once you hit 19.4, you're category 3. In that instance, you'd come down 1.2 for the first 3 shots under until you're 19.2, then you come down 0.6 for the last 2 you are under, so your new handicap would be 18.6.

You could get some slightly anomalous things going on, like if you're 18.4 and shoot 15 over, you'd come down 0.9 and become 17.5, which would leave you at 18 still. If you were 18.5 (i.e. slightly worse in theory at least) and shot 15 over, you would be 4 under your handicap, so you'd come down 1.2 and become 17.3. That meant if you were 18.5 you'd come down two strokes and 18.4 you would remain the same. Mostly that falls out in the wash though.

If you scored worse than your handicap, you had a "buffer zone". Your buffer zone was 1 stroke plus your category level, so category 1 the buffer zone was 2 strokes and category 4 it was 5 strokes. If you scored within your buffer zone of your handicap, your handicap didn't change. If you were worse than your buffer zone then your handicap would go up 0.1. That was 0.1 even if you were 30 over your handicap. 

I think the last vaguely pertinent point was that there was also a "Competition Scratch Score" or "CSS". That was an adjustment to SSS based on scoring on the day. It was based on the proportion of the field that scored within their buffer zone or better. That proportion also varied based on the composition of the field. The more category 4 players, the harder it was for CSS to go up and the easier for it to go down. That was similar in concept at least to PCC in the new system. CSS could be 1 below SSS, the same, 1 above, 2 above, or 3 above. There was then also a QRO status (qualifying reduction only), where it was 3 above and handicaps could only go down. That would only happen if scoring was genuinely awful. The powers that be never released the tables that were used to calculate CSS - I think to stop people from trying to fiddle the system.

On that last point, if the field was only category 1 players, the CSS would be much more likely to go up. That created a situation where a lot of better players would only play in those sorts of events and the CSS would go up a bunch and they'd protect their handicaps that way. My handicap mostly came down on those days and went up or stayed flat in club competitions with more diverse fields for that reason. I don't think that aspect worked as intended. 

So the better of a player you were, the slower the system would catch up with improvement and the worse you were, the slower the system would catch up with getting worse. Category 4 players who were improving would catch up with their new ability level pretty quickly. Category 1 not so much and none of them would catch up remotely quickly if you got worse. That was exacerbated by only competition rounds counting.