The Preservation of Golf Course Architecture

[Bryan Izatt]

Steve:

If the greens at Winged Foot were Stimping over 12 feet, you would just putt off most of them, because of the back-to-front tilt which is 3 to 4 % in many areas.  

Wouldn't the same be true of many, if not most golf courses? I hear people on this site throwing around speeds like 14' and 15' and I don't believe that would be playable for about 95% of courses. It certainly can't be sustainable for any length of time. At 15', what degree of slope could you have and still expect the ball to stop? (Assuming the air is perfectly still, of course.)

15' would be off the USGA chart, but the chart would seem to suggest that you could have marginal pin positions up to around 2.5* of slope.

[Steve Okula]

Bryan,

Nice find. That graph illustrates the point perfectly. 14' - 15' greens speeds must be exceedingly rare, if they happen at all.

[Jerry Kluger]

Can I ask what I believe to be a question which relates to the issue at hand: Do they intentionally alter green speeds during major championships based upon weather conditions?  Will they change them from day to day and try to increase or decrease speeds based upon factors such as wind and rain? 

[Sean Walsh]

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[jeffwarne]

Bryan,

Nice find. That graph illustrates the point perfectly. 14' - 15' greens speeds must be exceedingly rare, if they happen at all.

Which is why I'm so stunned EVERY time I see Mike Davis quoted as having those as target speeds for US Open courses. (at least twice)

Although lately you set the target speed, THEN modify the course.
That's at best backwards.

[Bryan Izatt]

It appears from the chart that as long as you keep the slope to less than 1.5* you can run the green speeds up to 15 or 16 or even higher and still have a recommended pin position.  Seems hard to believe.

[Steve Okula]

Can I ask what I believe to be a question which relates to the issue at hand: Do they intentionally alter green speeds during major championships based upon weather conditions?  Will they change them from day to day and try to increase or decrease speeds based upon factors such as wind and rain? 

In my experience prepping courses for Tour events, the pros value uniformity and consistency above all else, and for the average Tour event the players have quite a lot of influence over the set-up. They expect the green speeds to remain consistent from day to day and green to green throughout the week, from the practice rounds through Sunday, as much as possible given the weather. The European Tour, at least, insists on speeds from 9'6" to 10'6", no more, no less.

I never did a major, though, and those may be managed differently.

[Tom_Doak]

I'm not really sure I understand the chart.  It says specifically "slope in degrees", when we always measure things in terms of % ... 2.5% equals 2.5 feet of rise in 100 feet of length.  100 in 100 would be a 45 degree angle.

[Mac Plumart]

 the pros value uniformity and consistency above all else

 

http://www.golfclubatlas.com/forum/index.php/topic,42672.0.html

[John Chilver-Stainer]

Tom,

A good observation,
a conversion Table would give

1.0 degree   =  1.7 %
1.5 degrees  =  2.6 %
2.0  degrees =  3.5 %
2.5  degrees =  4.4 %
3.0  degrees =  5.2 %
3.5  degrees =  6.1 %
4.0  degrees =  5.2 %
4.5  degrees =  7.9 %
5.0  degrees =  8.8 %

This make more sense to me, as I thought a ball doesn't roll out on a 4.5% green with a Stimp of 7 feet.

[Bryan Izatt]

Tom,

Inclines can be expressed as a % or in degrees.  I'd imagine that all inclinometers provide output in either unit.  You can derive the % slope from the degrees of slope by the following formula:  % slope = tan (n*) x 100.  A 2.5* slope would be a 4.37% slope, or 4.37 feet rise in a hundred run.  The USGA chart appears to be in degrees, so if you were using it as guidance you could have a higher % slope using your measure and still be within their recommended or marginal slope.  

I don't recall now whether the discussion on the Eden green was in degrees or percentage, but it does make a difference.

I'm not really sure I understand the chart.  It says specifically "slope in degrees", when we always measure things in terms of % ... 2.5% equals 2.5 feet of rise in 100 feet of length.  100 in 100 would be a 45 degree angle.

[Paul_Turner]

Did Dawson claim the left side of 11th slope was 5%  (or 3degrees from tan calculation)?   

So at 10.5 stimp for an Open, it was in the yellow area but close to red.

Everyday play should have been at say 8-9 in stimp?  In the middle of the yellow.

[Ian Andrew]

Regardless of what the bottom says (degrees) its a percentage of slope on the bottom of the page.

[Robin_Hiseman]

Regardless of what the bottom says (degrees) its a percentage of slope on the bottom of the page.

Ian

I think it is degrees along the bottom, but that John has got his maths a bit wrong.

If a vertical slope can be expressed as either 90 degrees or 100 percent, there is only an 11% difference between the figures.

So 1 degree = 1.11%; 2 degrees = 2.22%, 3 degrees = 3.33% and so on until 90 degrees which = 99.99%.

This makes the chart seem much more logical to me.  I don't think it is any more complicated than this, is it?

[Mark Pearce]

Robin,

100% isn't a vertical slope, it's a 45 degree one (i.e. a rise of 100 feet in 100 feet).  A vertical slope would be expressed as an infinite percentage, since it doesn't have any horizontal component.

If the angle is a, then the slope as a percentage equals tan(a).

[Robin_Hiseman]

Mark

Happy to be corrected, in which case I apologise to John.

Regards

Robin
'O' Level Maths Grade B.  

[Ally Mcintosh]

Regardless of what the bottom says (degrees) its a percentage of slope on the bottom of the page.

Agree that it must be a typo...

[Robin_Hiseman]

I hope so Ally. 

It's actually a significant error if that table is wrong, which the author needs to clarify before someone builds something in error.  Either that, or we're all able to put much more slope into the hole locations than we believe...which I don't think is the case.

[Mark Pearce]

Robin,

Actually, I missed out a multiple of 100.  Tan (45 degrees) = 1, so Slope (as a percentage) = 100 tan (angle).

A 2 degree slope expressed as a percentage would be 3.49%

[Ally Mcintosh]

I hope so Ally. 

It's actually a significant error if that table is wrong, which the author needs to clarify before someone builds something in error.  Either that, or we're all able to put much more slope into the hole locations than we believe...which I don't think is the case.

I agree Robin.... Where did it come from - Hurdzan?

[Robin_Hiseman]

The USGA!!

An article by Jerry Lemons.

Here's the link.

http://www.usga.org/turf/green_section_record/2008/jul_aug/speeds_slopes_locations.pdf

[Bryan Izatt]

Yes, the chart I posted was from the USGA article by Jerry Lemons that Robin provided the link to. 

Ian, how do you know that the x-axis label is in error on the chart?

In the rest of the article that goes with the chart Lemons has used both degrees and % slope so he presumably knows the difference.  Some of the conclusions in the text seem to me to indicate that the chart is in degrees.

"Over the years, the Green Section
has suggested:
The slope of a major portion of a
putting green should usually not be
greater than 3 percent (1.7 degrees),
although some areas may exceed this
for special reasons, such as diffi cult
terrain or dramatic architectural
effect.15
Based on current information, any
slope 3% (1.7 degrees) or greater on a
10' Stimpmeter reading is too steep
for hole use.16"

If anyone wants to contact Lemons to see if the chart is in error, he can be contacted through his web site provided at the bottom of the article.

www.lemonsgolfdesign.com

How do you practicing architects measure slope in the field?  Are you guided by the USGA article or do you have your own rules of thumb?

[Ally Mcintosh]

Yes, the chart I posted was from the USGA article by Jerry Lemons that Robin provided the link to. 

Ian, how do you know that the x-axis label is in error on the chart?

In the rest of the article that goes with the chart Lemons has used both degrees and % slope so he presumably knows the difference.  Some of the conclusions in the text seem to me to indicate that the chart is in degrees.

"Over the years, the Green Section
has suggested:
The slope of a major portion of a
putting green should usually not be
greater than 3 percent (1.7 degrees),
although some areas may exceed this
for special reasons, such as diffi cult
terrain or dramatic architectural
effect.15
Based on current information, any
slope 3% (1.7 degrees) or greater on a
10' Stimpmeter reading is too steep
for hole use.16"

If anyone wants to contact Lemons to see if the chart is in error, he can be contacted through his web site provided at the bottom of the article.

www.lemonsgolfdesign.com

How do you practicing architects measure slope in the field?  Are you guided by the USGA article or do you have your own rules of thumb?

Bryan, that little excerpt actually confirms the opposite to me: The x-axis should read %ge slope.

All you need to do is think about the general numbers you see bandied about for quickish greens in that you don't pin anything over 2 to 2.5%.... If it were degrees it would be advocating that we could pin greens stimping 12 at about 4%... We better let Peter Dawson know!

[Ian Andrew]

Ian, how do you know that the x-axis label is in error on the chart?

The percentages exactly match the commonly held belief for percent of slope at each green speed.
Of course we can’t go below a certain grade up here because of ice, so it doesn’t match our circumstance.

How do you practicing architects measure slope in the field?

I use a frickin' laser. (said in Dr. Evil's voice)

Since every pin area must sit between 2% - 3.5% IN CANADA due to issues of ICE and OUR tyical grass selections. And because the vast majority of my work is on clay/shale, I need precision in the sub-grade and then again in the final grade of the mix to avoid localized wet or dry spots. The laser is critical.

I also check outlets of bunkers and the swales around the green during shaping to make sure what we are doing is going to work later. I hate area drains and catch basins, so extra laser work during construction eliminates helps eliminate almost all in advance.

Are you guided by the USGA article or do you have your own rules of thumb?

The USGA rules are generalized. Ice and excessive moisture held by native soils are the biggest issues I see regularly. I doubt Phoenix area courses share my list of problems and I would not be familiar with theirs. You need to learn what they are and amend your ideas to suit the environment. 

[Sven Nilsen]

What confuses me in reading the chart is the language on the right side.  It discusses proximity to areas of slope (at least for the the red area), not the slope at the pin, and does not seem to be consistent in usage across the color codes.