HC Format & Rounding Issues, Golf Genius vs. USGA Handicap Calculations

While I think that the advent of the slope system helped improve the portability of handicaps (even if not perfect), I think there are other ways the HC system can be improved.

I think the USGA could modernize itself by waiting as long as possible to round off as it can be MORE than a 1 stroke difference in some formats. i.e. on a course with a 131 slope, in Four Ball Stroke Play (better ball of partners), a 3.9 index plays even with a 5.6 index (both get 5 shots). On a 129 slope, in Best-Ball-of-Four Stroke Play, the 3.9 index has to give the 5.6 index two shots...so the spread in indexes is the same, but the shots went from 0 (in a 90% of HC game on a HARDER course) to 2 (in a 80% of HC game on an EASIER course). These results seem exactly opposite of what they should be...lower indexes should give MORE shots on harder courses and in games that use a HIGHER percentage of HC. If the USGA took the % of INDEX first, then computed CH before rounding, it would be 2 shot difference on the 131 slope and 1 shot difference on the 129 slope.

Also, I am curious to know how the USGA has calculated its various [handicap allowances](https://www.usga.org/handicapping/handicap-manual.html#!rule-14370 "handicap allowances") for various formats. While looking at historical scores might have yielded some rough results years ago, I think a deeper analysis could be done using results of specific competitions entered with software like Golf Genius. Do the old recommendations (I think from the 1970s or 1980s) match actual competitive results of the 21st Century?

It is my understanding that that there is a [partnership](https://www.mgagolf.org/news/2017/january/usga_golfgenius "partnership") between the USGA & Golf Genius software so why do they compute team handicaps differently in certain circumstances (by rounding at different times)? FWIW, I think the way Golf Genius does it is fairer than the way the USGA says to do it, but find the use of different methods confusing.

Golf Genius: http://docs.golfgenius.com/article/show/22435-tournament-handicap-options

60%+40% Chapman/Greensomes: Available for pair v. field scramble and alternate shot tournaments, take 60% of the A Player's Course Handicap + 40% of the B Player's Course Handicap. For instance, if Karen (8 Course Handicap) and Linda (14 Course Handicap) are partners, their team Course Handicap would be 10. ([8x.6] +[14x.4) = 10.4 (Round down to get 10).

USGA: https://www.usga.org/handicapping/handicap-manual.html#!rule-14387

(vii) Chapman or Pinehurst Stroke Play

In Chapman or Pinehurst stroke play, two players play as partners, each partner plays from the teeing ground and plays the partner's ball for the second shot. After the second shot, partners select the ball with which they wish to score and play that ball alternately to complete the hole. After handicap allowances are determined, Section 9-3c(iii) must be applied in competitions from different tees or in competitions between men and women from the same tees.

Allowance: The player with the lower Course Handicap is allowed 60 percent of Course Handicap. The player with the higher Course Handicap is allowed 40 percent of Course Handicap.

Example: On side A-B, Player A has a Course Handicap of 10 and Player B has a Course Handicap of 18. 60% of Player A's Course Handicap is 6 (10 x 60%) and 40% of Player B's Course Handicap is 7 (18 x 40% = 7.2, rounded to 7) so the total is 13. Side A-B receives 13 strokes.

So, in the Golf Genius example of Karen (8 x 60% = 4.8, rounds to 5) and Linda (14 x 40% = 5.6, rounds to 6), their team Course Handicap would be 11 under the USGA method of rounding each player's cap prior to combining. With the way the USGA does it, you could have a team with a HIGHER combined index having to GIVE a shot to a team with a LOWER combined index.

Without commenting on anything else as I'm not under the USGA system, you need to look at both, the Course Rating and the Slope to determine which course and set of tees is more difficult to a player.

I think you are assuming that handicap indices are a way more precise estimate of ability than they truly are.

Even the fact they report the index to a tenth of a stroke is false precision in the extreme. Worrying over rounding "errors" of up or down one stroke would only make sense if you index were some physical quantity rather than an abstract, very approximate indicator of "current" "ability".

> @Halebopp said:

> Without commenting on anything else as I'm not under the USGA system, you need to look at both, the Course Rating and the Slope to determine which course and set of tees is more difficult to a player.

I get that...let's assume the same Course Rating. My thinking (which is in line with how I understand the USGA slope system) is that the 131 slope is suppose to be more difficult for most players than the 129 slope. Do you see it differently?

FWIW, this post isn't challenging the slope and course rating system, rather it is questioning where rounding should take place and whether the USGA handicap allowances from last century are as accurate as they could be.

I think it is more accurate to round less and at the end, rather than more often and earlier. I also think that there must be a treasure trove of info from this century that can be used to validate or improve the handicap allowances for different formats.

Given the same course rating, the higher the slope, the more **_increasing_** in difficulty it is for higher handicappers. In other words, the difference between a scratch golfer and worse than scratch golfer, the spread between the two increases as the slope gets farther from 113. "Slope" is given that name because it's based on the slope of a graph, with 113 being a "flat" slope.

A 0 index and a 10 index have a 10 shot difference between them on a tee box with a 113 slope, but an 11 shot difference between them on a course with a 124 slope, because 124 is 10% higher than 113.

I do agree that there seems to be one too many times a player's course handicap is rounded. In the end, it all averages out, but you could be on the short end of the stick for any single match (or you could be receiving 1 extra shot for any single match).

> @larrybud said:

> Given the same course rating, the higher the slope, the more **_increasing_** in difficulty it is for higher handicappers. In other words, the difference between a scratch golfer and worse than scratch golfer, the spread between the two increases as the slope gets farther from 113. "Slope" is given that name because it's based on the slope of a graph, with 113 being a "flat" slope.

>

> A 0 index and a 10 index have a 10 shot difference between them on a tee box with a 113 slope, but an 11 shot difference between them on a course with a 124 slope, because 124 is 10% higher than 113.

>

> I do agree that there seems to be one too many times a player's course handicap is rounded. In the end, it all averages out, but you could be on the short end of the stick for any single match (or you could be receiving 1 extra shot for any single match).

Or you could be improving or getting worse faster than GHIN can keep up. Or your course could be rated 70.3/134 when it ought to be 70.5/136 because some trees have grown in. Or they've got the tees way up on a couple of the Par 5's today. Or any of 100 other scenarios that would change your handicap by a stroke on a given day.

It's a bunch of highly variable and subjective numbers pasted together into an arbitrary formula. It doesn't parse out to an exact, objective, measurable quantity.

I know you can find specific sets of numbers that show a result that might be called "unfair". I'd bet that you could show a different set of numbers where the results were "unfair" in the opposite direction. I agree in principle, the fewer times that numbers get rounded, the more accurate the result is likely to be. On the other hand, it makes some sense to consistently determine a course handicap, a whole number, as the first step in every case. That's the first step, always, so its consistent. Subsequent modifications and/or combinations of of course handicaps come with their own set of rounding, but the first step is always the same.

> @SkiSchoolPro said:

> > @Halebopp said:

> > Without commenting on anything else as I'm not under the USGA system, you need to look at both, the Course Rating and the Slope to determine which course and set of tees is more difficult to a player.

>

> I get that...let's assume the same Course Rating. My thinking (which is in line with how I understand the USGA slope system) is that the 131 slope is suppose to be more difficult for most players than the 129 slope. Do you see it differently?

> FWIW, this post isn't challenging the slope and course rating system, rather it is questioning where rounding should take place and whether the USGA handicap allowances from last century are as accurate as they could be.

> I think it is more accurate to round less and at the end, rather than more often and earlier. I also think that there must be a treasure trove of info from this century that can be used to validate or improve the handicap allowances for different formats.

I know it wasn't the point of your post but for whatever reason I felt like replying to that bit.

Yes, I agree the 131 should be very slightly more difficult of the two if the CRs are the same but the difference is so minimal you could call them basically the same because of the divisor of 113.

The CR plays a much bigger role. For example, 131 is 1.6% more than 129 and a CR of 70.9 is 1.6% bigger than 69.8. If you have two courses, 70.9/129 and 69.8/131, the latter would be the easier course all the way up to players with handicaps of 60 (that's without rounding the numbers, with rounding they're the same from about 23 handicap all the way up to the 90s). Of course, handicaps don't go north of 54 anywhere.

I do agree rounding at the end would make things more accurate (but by how much and is it lost in all the other noise)? I'm not a fan of the USGA method of counting playing handicaps (excluding the CR). Using both is the best way to go.

> @davep043 said:

> I know you can find specific sets of numbers that show a result that might be called "unfair". I'd bet that you could show a different set of numbers where the results were "unfair" in the opposite direction.

>

Agreed. My point is it is better to try to avoid unfairness in either direction.

Below is a table that shows how many more shots a 5.6 gets than a 3.9 in different formats. IMO, lots of anomalies due to when the rounding takes place (and also because you calculate CH for each player rather than looking first at the difference between the two, but let's forget that for a moment):

Slope 100% HC 90% HC 80% HC 60% HC

110 1 1 1 1

111 2 1 2 2

112 2 1 2 2

113 2 1 2 2

114 2 1 2 2

115 2 1 2 2

116 2 1 2 2

117 2 1 2 2

118 2 1 2 2

119 2 1 2 2

120 2 1 2 2

121 2 1 2 2

122 2 1 2 2

123 2 1 2 2

124 2 1 2 2

125 2 1 2 2

126 2 1 2 2

127 2 1 2 2

128 2 1 2 2

129 2 1 2 2

130 2 1 2 2

131 1 0 1 1

132 2 1 2 1

133 2 1 2 1

134 2 1 2 1

135 2 1 2 1

136 2 1 2 1

137 2 1 2 1

138 2 1 2 1

139 2 1 2 1

140 2 1 2 1

141 2 1 2 1

142 2 1 2 1

143 2 1 2 1

144 2 1 2 1

145 2 1 2 1

146 2 1 2 1

147 2 1 2 1

148 2 1 2 1

149 2 1 2 1

150 2 1 2 1

151 2 1 2 1

152 3 2 2 2

153 3 2 2 2

154 3 2 2 2

155 3 2 2 2

> @davep043 said:

> I agree in principle, the fewer times that numbers get rounded, the more accurate the result is likely to be. On the other hand, it makes some sense to consistently determine a course handicap, a whole number, as the first step in every case. That's the first step, always, so its consistent. Subsequent modifications and/or combinations of of course handicaps come with their own set of rounding, but the first step is always the same.

>

In most cases, like when you play match play head to head with your buddies or events where you play 100% of course HC, calculating the course handicap is the first and LAST step. I think instructions that made it the first/last step with additional steps based on format could be just as easy to understand as the current instructions found at: https://www.usga.org/handicapping/handicap-manual.html#!rule-14387

9-4. Handicap Allowances

Handicap allowances have no effect in determining a Handicap Index; however, their use is recommended to produce fair and equitable competition.

A Handicap Index relates to 18 holes. Each allowance in Section 9-4 applies to an 18-hole round, even though the competition may consist of more than one round.

The allowances are designed to make all forms of play fair. In some forms of play, it is equitable for players to use full Course Handicap. In some team competitions, using full Course Handicap would give higher-handicapped sides an advantage over lower-handicapped sides. Less than full Course Handicap is recommended in some team competitions.

To make proper use of handicap allowances, follow the order of the steps below:

Step 1: Players must first determine Course Handicap (from tees played).

Step 2: Players should then apply the handicap allowances for the appropriate format.

Step 3: It is recommended that in four-ball stroke play competitions, if the Course Handicaps of the side differ by more than eight strokes, each is reduced by 10 percent. (See Note in Section 9-4b(ii).)

Step 4: If players are competing from different tees or men and women are competing from the same tees (See Sections 3-5 and 9-3c), players must apply the adjustment for the difference in USGA Course Rating from the tees played.

Example: A competition in which players using a handicap allowance of 80 percent are playing from two sets of tees where the difference in USGA Course Rating is four strokes. Player A's Course Handicap of 30 is first reduced by six strokes to 24 (30 x 80% = 24), then increased by four strokes to 28 (24 + 4 = 28). Had the order of adjustment been incorrectly reversed, A's Course Handicap of 30 would first have been increased by four strokes to 34 (30 + 4 = 34), then reduced by seven strokes to 27 (34 x 80% = 27.2, rounded downward to 27) - a loss of one stroke.

The amount of the adjustment in Step 4 is added to Course Handicap, even if it causes a Course Handicap to exceed the maximum Handicap Index. (See Section 3-4.)

Note 1: In match play formats where the lower-handicapped player plays at scratch, and due to Step 4 is not at scratch, repeat Step 2 if necessary.

Note 2: If the percentage of a player's Course Handicap results in a decimal in Steps 2 and/or 3 above, the resulting figure is rounded to the nearest whole number (.5 or more is rounded upward).

Well, it ain't goin' to change soon.

> @Newby said:

> Well, it ain't goin' to change soon.

For those using Golf Genius software, it may have already changed, at least for some formats.

I should add that the rounding problem can get worse in team comps when using the USGA method. In Pinehurst/Chapman a 2.3 partnered with a 3.2 would play even against a 3.9 partnered with a 5.6 on a 130 slope course. This would be the same even if the 2.3 or 3.2 was a Sr playing a box up with a 125 slope and CR of 0.8 less. If using the Golf Genius method, the 3.9 & 5.6 would get 2 shots.

Of course, a 2.0 & 4.0 would have to give the 2.3 & 3.2 a shot in either scenario using the USGA method (all playing 130 or one of the 2.3/3.2 playing up a box). Using the Golf Genius method, they would play even.

> @"North Butte" said:

> > @larrybud said:

> > Given the same course rating, the higher the slope, the more **_increasing_** in difficulty it is for higher handicappers. In other words, the difference between a scratch golfer and worse than scratch golfer, the spread between the two increases as the slope gets farther from 113. "Slope" is given that name because it's based on the slope of a graph, with 113 being a "flat" slope.

> >

> > A 0 index and a 10 index have a 10 shot difference between them on a tee box with a 113 slope, but an 11 shot difference between them on a course with a 124 slope, because 124 is 10% higher than 113.

> >

> > I do agree that there seems to be one too many times a player's course handicap is rounded. In the end, it all averages out, but you could be on the short end of the stick for any single match (or you could be receiving 1 extra shot for any single match).

>

> Or you could be improving or getting worse faster than GHIN can keep up. Or your course could be rated 70.3/134 when it ought to be 70.5/136 because some trees have grown in. Or they've got the tees way up on a couple of the Par 5's today. Or any of 100 other scenarios that would change your handicap by a stroke on a given day.

>

> It's a bunch of highly variable and subjective numbers pasted together into an arbitrary formula. It doesn't parse out to an exact, objective, measurable quantity.

While those things are true, the formula itself isn't subjective. Why introduce a level of error into a simple formula when it can be avoided?

> > @davep043 said:

> In most cases, like when you play match play head to head with your buddies or events where you play 100% of course HC, calculating the course handicap is the first and LAST step. I think instructions that made it the first/last step with additional steps based on format could be just as easy to understand as the current instructions found at: https://www.usga.org/handicapping/handicap-manual.html#!rule-14387

All they would have to do is if different tee boxes are used, don't round your adjustment after slope is applied. Round it after the course rating difference is applied.

Example- current method, two players playing two different tee boxes.

10.0 index, 70/120

4.6 index, 72.6/135

Current method: the 10 would be an 11 course handicap (10.6 rounded to 11)

The 4.6 would be a 6 course handicap (5.5 rounded to 6).

Diff of 5 shots, subtract the course rating, the higher capped player would get (5-2.6=2.4) 2 shots.

Now wait on the rounding

10.6 vs 5.5, difference is 5.1. 5.1 - 2.4 shots = 2.7, the higher capped player would get 3 shots.

Why introduce multiple rounding errors when it's not necessary?

> @larrybud said:

> Why introduce multiple rounding errors when it's not necessary?

Because they are entirely meaningless. The rounding "errors" (as you yourself point out, if you follow the formula then it's not an error, the round formula is quite "objective") do not systematically favor anyone. They just move the result by a stroke on more or less random occasions, sometimes they don't change anything at all.

You might as well be complaining that the system uses the best 10 out of 20 rounds rather than the best 12 out of 24. That change would also occasionally produce a slightly different handicap but on average it is meaningless.

Players usually enter a competition expecting that all the Rules of golf will be in effect. This player broke a very basic and fundamental Rule which results in DQ. Really, what is the problem when the Rule is applied as everyone expected?

> @Newby said:

> Well, it ain't goin' to change soon.

Not for a few months anyways

> @"North Butte" said:

> > @larrybud said:

> > Why introduce multiple rounding errors when it's not necessary?

>

> Because they are entirely meaningless. The rounding "errors" (as you yourself point out, if you follow the formula then it's not an error, the round formula is quite "objective") do not systematically favor anyone. They just move the result by a stroke on more or less random occasions, sometimes they don't change anything at all.

Yep, they move it a stroke one way or another 50% of the time, when it's not necessary to do so.

I am in the Round-as-late-as-possible camp: https://forums.golfwrx.com/discussion/1709584/poll-1-on-1-match-course-handicaps-the-usga-way

@larrybud @lchang nice to get some support for rounding once at the end (instead of up to 3 times)

> @"North Butte" said:

> > @larrybud said:

> > Why introduce multiple rounding errors when it's not necessary?

>

> Because they are entirely meaningless. The rounding "errors" (as you yourself point out, if you follow the formula then it's not an error, the round formula is quite "objective") do not systematically favor anyone. They just move the result by a stroke on more or less random occasions, sometimes they don't change anything at all.

>

> You might as well be complaining that the system uses the best 10 out of 20 rounds rather than the best 12 out of 24. That change would also occasionally produce a slightly different handicap but on average it is meaningless.

Unlike selecting 10 out of 20 vs 12 out of 24, I think multiple rounding does favor some indexes over others. Foursome stroke play (partner best ball) is a pretty common event that is suppose to be played at 90% of cap (I believe with the recommendation of a further 10% decrease for sides where the partners are more than 10 strokes apart). Guys who are 5 and less caps get no reduction while a 6 (to 15 cap) gets a full shot reduction...much better to be a 4 or 5 than a 6 or 7. If you are on a tournament committee, you are not going to have to explain why you are using 10 out of 20, but you might have to explain why a 4.3 is playing even with a 6.1 when using 90% cap on a 120 slope course.

Also, at courses where the Sr tees CR are not a integer away from the CR of the other competitors, the Seniors are either going to be consistently favored (i.e. if their CR is 1.4 lower) or hurt (i.e. if their CR is 1.5 lower). This effect can be negated or exasperated depending on the slope and each players index. At both leagues I have played, the Seniors are given the CHOICE of which box to play- this means they get the chance to see if the 2 rounds (slope & CR diff) effects them positively or negatively before deciding on which box to play...having this choice is a clear advantage for seniors.

The other issue for a tournament committee is that the USGA's partner software, Golf Genius, appears not to always round the same as the USGA says to. So, what do you do when you post results and the second place team protests that they should be 1st when using the USGA rounding method???

Also, while people saying that there’s more precision in the numbers than actual difference I’m real-life ability: sure. But why intentionally make it less theoretically representative. How many net nassaus come down to a putt on the 18th? Seems like a lot to me! (I love that competitive drama, and I like the handicap system!)

> @SkiSchoolPro said:

Foursome stroke play (partner best ball) is a pretty common event

>

I hope you meant Four-ball. I would suggest that Foursomes are rarely played over there.

> @Newby said:

> > @SkiSchoolPro said:

> Foursome stroke play (partner best ball) is a pretty common event

> >

> I hope you meant Four-ball. I would suggest that Foursomes are rarely played over there.

>

Yes, whichever one is partner best ball...I find that term and alternate shot to be much more descriptive than Foursome and Four-ball.

> @SkiSchoolPro said:

> > @Newby said:

> > > @SkiSchoolPro said:

> > Foursome stroke play (partner best ball) is a pretty common event

> > >

> > I hope you meant Four-ball. I would suggest that Foursomes are rarely played over there.

> >

>

> Yes, whichever one is partner best ball...I find that term and alternate shot to be much more descriptive than Foursome and Four-ball.

Especially for most people that only hear those terms every two years at Ryder Cups and similar competitions. We refuse to use those terms. Espect the foursomes because our interclub tournament, the River Cup changes which format of alternate shot we use every year. I'm always stuck in that format and I hate it.

> @SkiSchoolPro said:

> > @Newby said:

> > > @SkiSchoolPro said:

> > Foursome stroke play (partner best ball) is a pretty common event

> > >

> > I hope you meant Four-ball. I would suggest that Foursomes are rarely played over there.

> >

>

> Yes, whichever one is partner best ball...I find that term and alternate shot to be much more descriptive than Foursome and Four-ball.

We usually say 'Better Ball' or write 4BBB (Four Ball Better Ball) as 'better' is a comparative rather than using superlative.

See https://forums.golfwrx.com/discussion/comment/19101261#Comment_19101261

@Newby @SNIPERBBB @"North Butte"

Whether its better or best ball or fourball or Pinehurst or Chapman, what would you do if you were on the tournament committee and the 2nd place team protests after the results have been posted because the software you used rounded differently than the USGA says to do it?

What would you do if the two USGA methods for adjusting for different tee boxes produced different results?

> @SkiSchoolPro said:

> @Newby @SNIPERBBB @"North Butte"

> Whether its better or best ball or fourball or Pinehurst or Chapman, what would you do if you were on the tournament committee and the 2nd place team protests after the results have been posted because the software you used rounded differently than the USGA says to do it?

> What would you do if the two USGA methods for adjusting for different tee boxes produced different results?

I wouldn't worry a jot. CONGU doesn't have such silliness :)

> @Newby said:

> > @SkiSchoolPro said:

> > @Newby @SNIPERBBB @"North Butte"

> > Whether its better or best ball or fourball or Pinehurst or Chapman, what would you do if you were on the tournament committee and the 2nd place team protests after the results have been posted because the software you used rounded differently than the USGA says to do it?

> > What would you do if the two USGA methods for adjusting for different tee boxes produced different results?

>

> I wouldn't worry a jot. CONGU doesn't have such silliness :)

How does it work in CONGU? Do you guys play any formats where a % of your handicap (or equivalent) is used?

> @SkiSchoolPro said:

> > @Newby said:

> > > @SkiSchoolPro said:

> > > @Newby @SNIPERBBB @"North Butte"

> > > Whether its better or best ball or fourball or Pinehurst or Chapman, what would you do if you were on the tournament committee and the 2nd place team protests after the results have been posted because the software you used rounded differently than the USGA says to do it?

> > > What would you do if the two USGA methods for adjusting for different tee boxes produced different results?

> >

> > I wouldn't worry a jot. CONGU doesn't have such silliness :)

>

> How does it work in CONGU? Do you guys play any formats where a % of your handicap (or equivalent) is used?

Yes but there is only one method used for rounding, the one in the CONGU manual

Have you asked Golf Genius about the rounding discrepancy?