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Clyde Johnson

  • Karma: +0/-0
I won't try to do total ascent for St. Patrick's because I am not sure exactly how it is being calculated, but the elevation change is 68 feet [22 m] from the 16th tee at 86 feet to the 4th fairway at 18 feet.  I'm not surprised that is more than all the ranked UK links courses except for Cruden Bay and Castle Stuart.  It's just above the midpoint for the top 100 overall.


St Patrick's is 235ft from 1st tee to 18th green, looking back at my running stats from construction. A shade over 5 miles total too.

Jeff Schley

  • Karma: +0/-0
Very interesting Jeff.  A couple of questions:


I expected somewhere like TOC to be much shorter from tee to green but I guess this is based on The Open tees so lots of walks back to tee boxes?


Does total ascent just take the elevation of green and tee and derive a number assuming a that descent / ascent to be level? The one that jumped out was Rye, which crosses a large line of dunes in the middle of a couple of holes.  It makes it quite a hike even though greens and tees maybe at similar levels.  Similarly, would a hole like the Alps / Himalayas come out as fairly flat?  Just some odd rankings of ascent where the numbers seem to differ from experience that I’m trying to reconcile.


Adam, I'll try and answer best I can.


  • For the TOC tees, yes it is the furthest back tees. This is the default of provisualizer and agreed it is not what the vast majority of golfers would experience.
  • The Total Ascent is walking in a straight line from the tee to the next shot to the middle of the green. It measures only the total uphill ascent without a net or factoring in the downhill. So if you traverse a valley on your way to your next shot that is factored into the Total Ascent calculation. From Point A you traverse -8  downhill and then +7 uphill through a valley it would add 7 meters to the Total Ascent, although your shot comes to rest 1 meter below where you hit it.
  • Of note is that the Total Ascent includes the green to tee transitions, but only as a straight line, which is not reality as we use paths.
"To give anything less than your best, is to sacrifice your gifts."
- Steve Prefontaine

Jeff Schley

  • Karma: +0/-0
Jeff:
I think the green to tee walk data is very skewed by the insistence on using the furthest back tees (which hardly anyone plays) as the standard.  As Adam says, you can hardly have an easier walk than The Old Course at St Andrews, yet it comes out in the middle of your list.


In some cases this will also throw off the total climb figures significantly.


Tom, You are correct and agree the overwhelming majority would experience less walking and ascent as the provisualizer's default is the back tees. Working with free public information, although using google earth someone could do it from the normal tee. Provisualizer allows people to map their own courses, however not upload it to their site I learned. Thus, for all 3,000 plus courses they are done by them over the years and always from the back tee.


Of note is that the distance to the back tee is a low end number because they measure as the crow flies. So it will always be more and in some cases if you walk around a peak decrease the Total Ascent, or perhaps increase it based on where the walking/cart paths are. Unless someone takes the painstaking process of actually mapping an actual routing using Google Earth it is a rough estimate. The time investment to do so perhaps is negligible, outside of our group. But I'd love to have it. :)
"To give anything less than your best, is to sacrifice your gifts."
- Steve Prefontaine

Jeff Schley

  • Karma: +0/-0
Jeff--


really interesting.  like anything else the devil is in the details.  2 questions came to me:


1.  when you measure distance walked on a hole, what "path" is assumed if there is water that must be crossed?  good example is par 3 #17 at TPC Sawgrass...does this assume the player is named Moses and walks over water for about 135 yards, or that he is a mere mortal and takes the walking path which is probably over 200 yards?  same question applies in walks from green to next tee...for example from 16th green at TPC Sawgrass to 17th tee


2.  there are a huge number of holes where it is either (1) sharply uphill off the tee and then downhill or (2) sharply downhill off the tee and then uphill (#1 at ANGC off the tee is a great example of the second case).  So let's assume that the drive landing area in both of these examples is 2 meters higher (in altitude) that the back tees.  As I understand it, your methodology would say the player walked 2 meters uphill...when he probably walked more like 10-meters or so uphill partially offset by 8 meters downhill.  One way to "correct" for this might be to measure altitude every 5 meters or so along the ground...which would get a much closer approximation of the actual vertical climb.  It is important to remember that downhill walks do not "save energy" to offset uphill walks.  In fact...I believe downhill walks are more strenuous than flat walks as your legs must act as "brakes"...which is probably why people who run marathons have real trouble walking downstairs a day or two after a marathon).


believe all of above and other questions likely correctable...just that it will make the data gathering and algorithms more complicated and require additional research...like asking a physiologist about stress of downhill walks


Paul thanks for chiming in.  If there is a list guy I know it is you! ;D


For your first question. I heard back from Provisualizer that the green to next tee IS as the crow flies and a lower end estimate. So in many cases the distance and total ascent are low estimates and with some courses the transitions are substantial. So with this information it identifies a limitation of the data, that although the same for all, it isn't actual and at the low end. How much it varies for some courses (TPC Sawgrass) vs. TOC for example are considerable. Also the tee boxes are always the back one, which normal golfers don't use.


The second question is interesting and agreed that it could be that downhill walking is more rigorous than level. I don't know the answer to that and welcome others opinions. If that is the case, yet another complexity.
"To give anything less than your best, is to sacrifice your gifts."
- Steve Prefontaine

Jeff Schley

  • Karma: +0/-0
I won't try to do total ascent for St. Patrick's because I am not sure exactly how it is being calculated, but the elevation change is 68 feet [22 m] from the 16th tee at 86 feet to the 4th fairway at 18 feet.  I'm not surprised that is more than all the ranked UK links courses except for Cruden Bay and Castle Stuart.  It's just above the midpoint for the top 100 overall.


St Patrick's is 235ft from 1st tee to 18th green, looking back at my running stats from construction. A shade over 5 miles total too.


I requested that provisualizer to map the three courses they are missing for the Top 100 including St. Patrick's (Les Bordes, Ardfin). In a couple weeks hopefully it will be posted. I'd be very curious how their calculations reconcile with your topo maps and plans.
"To give anything less than your best, is to sacrifice your gifts."
- Steve Prefontaine

Sean_A

  • Karma: +0/-0
I still can't see how Merion has 500 feet of climbing. I don't remember anything like that sort of walk.

Ciao


That's part of the beauty of Merion. Can't say it's 500 feet, but it's a lot. The elevation is subtle in some places and spread across many holes. IIRC, there are uphill walks on parts or all of #2, #3, #4, #7, #10, #12, #13, #14, #16 and #18

Thats an average of 28 feet a hole over 18 holes. Not far off half the holes are either flattish or downhill. So we are not looking at an average of 50 plus feet over almost golf the course. What do you reckon is highest ascent? I have no memory of any seriously uphill shots.. maybe 3, 16 and 18, but I would have said they were maybe 25 feet ascent.

Ciao


Sean:


I was surprised by those figures, too, so I went to look on Google Earth.  The highest point is 16 tee at 390 feet; the lowest is 11 green at 286.  But then the 6th green is also 369 feet.


Biggest elevation changes:


2nd (45'), 3rd (17'), 5th (22'), 6th (25'), 10th (down 30 to stream then up 28'), 12th (15'), 14th (38'), 15th (22').


But those only add up to half the total cited, and I don't think the green to tee walks are enough to make up the other half.

I find the number shocking. The reason is that when Cleeve Hill was measured walking the course the up and down was something like 550 feet from memory. That is up and down, so roughly 275 feet ascent. I can't belive Merion is 200 feet more of climbing. I wonder what the app says for Cleeve?

Ciao
New plays planned for 2024: Nothing

Adam Uttley

  • Karma: +0/-0
Thanks for the clarification Jeff.  My mind is officially blown as the total ascent in so many cases does not correlate to my perception.  I wonder if this is a data granularity issue or that ease of walking a course is much less affected by total ascent and instead by steepness of ascent with only certain gradients affecting us?  Or perhaps there are so many factors (heat, wind, rough length) that give rise to a more arduous day that ascent is merely masked.


Anyway, these were three pairs of courses I pulled out where I couldn’t get my head round the comparisons:


Woodhall Spa 61 vs Rye Old 37
Koninklijke Haagsche 71 vs Swinley Forest 78

and perhaps the most surprising:

Brandon Dunes 105 vs Bandon Trails 72

Adam Uttley

  • Karma: +0/-0
I still can't see how Merion has 500 feet of climbing. I don't remember anything like that sort of walk.

Ciao


That's part of the beauty of Merion. Can't say it's 500 feet, but it's a lot. The elevation is subtle in some places and spread across many holes. IIRC, there are uphill walks on parts or all of #2, #3, #4, #7, #10, #12, #13, #14, #16 and #18

Thats an average of 28 feet a hole over 18 holes. Not far off half the holes are either flattish or downhill. So we are not looking at an average of 50 plus feet over almost golf the course. What do you reckon is highest ascent? I have no memory of any seriously uphill shots.. maybe 3, 16 and 18, but I would have said they were maybe 25 feet ascent.

Ciao


Sean:


I was surprised by those figures, too, so I went to look on Google Earth.  The highest point is 16 tee at 390 feet; the lowest is 11 green at 286.  But then the 6th green is also 369 feet.


Biggest elevation changes:


2nd (45'), 3rd (17'), 5th (22'), 6th (25'), 10th (down 30 to stream then up 28'), 12th (15'), 14th (38'), 15th (22').


But those only add up to half the total cited, and I don't think the green to tee walks are enough to make up the other half.

I find the number shocking. The reason is that when Cleeve Hill was measured walking the course the up and down was something like 550 feet from memory. That is up and down, so roughly 275 feet ascent. I can't belive Merion is 200 feet more of climbing. I wonder what the app says for Cleeve?

Ciao


Cleeve not mapped, but a few others:


Reddish: 40m elev, 97m ascent
Cavendish: 46m elev, 128m ascent
JCB: 26m elev, 106m ascent

Sean_A

  • Karma: +0/-0
I still can't see how Merion has 500 feet of climbing. I don't remember anything like that sort of walk.

Ciao


That's part of the beauty of Merion. Can't say it's 500 feet, but it's a lot. The elevation is subtle in some places and spread across many holes. IIRC, there are uphill walks on parts or all of #2, #3, #4, #7, #10, #12, #13, #14, #16 and #18

Thats an average of 28 feet a hole over 18 holes. Not far off half the holes are either flattish or downhill. So we are not looking at an average of 50 plus feet over almost golf the course. What do you reckon is highest ascent? I have no memory of any seriously uphill shots.. maybe 3, 16 and 18, but I would have said they were maybe 25 feet ascent.

Ciao


Sean:


I was surprised by those figures, too, so I went to look on Google Earth.  The highest point is 16 tee at 390 feet; the lowest is 11 green at 286.  But then the 6th green is also 369 feet.


Biggest elevation changes:


2nd (45'), 3rd (17'), 5th (22'), 6th (25'), 10th (down 30 to stream then up 28'), 12th (15'), 14th (38'), 15th (22').


But those only add up to half the total cited, and I don't think the green to tee walks are enough to make up the other half.

I find the number shocking. The reason is that when Cleeve Hill was measured walking the course the up and down was something like 550 feet from memory. That is up and down, so roughly 275 feet ascent. I can't belive Merion is 200 feet more of climbing. I wonder what the app says for Cleeve?

Ciao


Cleeve not mapped, but a few others:


Reddish: 40m elev, 97m ascent
Cavendish: 46m elev, 128m ascent
JCB: 26m elev, 106m ascent

I must not understand the concept, the up and down readings I received for Cleeve Hill, Kington, Welshpool and Church Stretton are well off or this ascent only concept has virtually no bearing in how I am trying figure out the tougher walks using data.

Ciao
New plays planned for 2024: Nothing

Kalen Braley

  • Karma: +0/-0

I had Jeff send me a copy of the xls and I made an attempt at a "Rigor Factor 1.0" Ranking that he asked for in post #10. Its just a first stab, but figured to start somewhere.  ;)

The following ranking considers the data provided by Provisualizer:
1)  Amount of ascent when walking the course.
2)  Total distance of walk (including green to tee transitions)
3)  The % additional added by green to tee transitions.

I ranked every course for each category and then calculated an average ranking value, which was then "ranked" in the following list from lowest to highest.  This list shows how courses compare to each for the amount of uphill walking, total distance to walk, and shortest green to tee transitions relative to each other. The "better" (less uphill walks, and shorter distance) a course does across those 3 categories, the higher it will appear in the ranking. 

Ranking     Course        Avg
1   Utrechtse De Pan   4.7
2   North Berwick       6.7
3   Rye Old   8.0
4   Fishers Island    11.0
5   Prestwick   13.0
6   Royal Melbourne East   19.7
7   Winged Foot East   20.7
8   Shoreacres    21.3
9   St George's Hill   22.3
10   NGLA    23.3
11   Chicago GC    24.0
11   Swinley Forest   24.0
13   Morfontaine   25.7
14   Royal Melbourne West   26.0
15   Yeamans Hall   28.3
16   Royal Troon   30.0
17   Carnoustie   30.3
18   Quaker Ridge   32.0
19   Ballybunion   32.7
20   Tara Iti    33.0
21   Garden City    33.3
22   Hirono   34.3
23   Somerset Hills   35.0
24   Myopia Hunt   35.3
25   Sand Hills    35.7
26   Seminole   37.3
27   Barnbougle Dunes   37.7
27   Royal Liverpool    37.7
29   Koninklijke Haagsche   38.0
30   Lahinch   38.7
31   Woodhll Spa Hotchkin   39.7
31   Sunningdale New   39.7
33   Pinehurst No. 2   40.3
34   Friar's Head   40.7
34   Old Town   40.7
36   Cypress Point    41.3
36   Oakland Hills   41.3
38   Royal Lytham & St Annes   41.7
39   Ohoopee Match Club   42.0
40   Southern Hills   42.3
41   St. Andrews TOC   43.3
42   Pine Valley    43.7
42   Bandon Trails   43.7
44   Prairie Dunes   44.0
45   Royal Dornoch    44.3
46   St George's Golf   44.7
47   Cabot Cliffs   45.0
48   Ballyneal   45.3
49   Baltursol   45.7
50   Maidstone   46.0
51   Royal County Down   47.0
51   Cape Wickham   47.0
53   Camargo   48.0
54   Cabot Links   50.3
55   Curden Bay   51.3
56   Muirfield   51.7
57   Kawana    52.7
58   Pebble Beach   53.7
58   Winged Foot West   53.7
60   San Francisco   54.7
60   Royal Birkdale   54.7
62   Pacific Dunes   56.0
63   Kingston Heath   56.7
64   Crystal Downs    57.0
64   New South Wales   57.0
66   Royal Portrush   57.7
66   Royal St. George's   57.7
68   Sunningdale Old   58.7
69   Riviera   59.0
70   Portmarnock   59.3
70   Sleepy Hollow    59.3
72   The Golf Club   63.7
73   Turnberry   64.3
74   The CC at Brookline    67.7
75   Castle Stuart   68.3
76   Kingsbarns    69.7
77   Merion    70.0
78   Augusta National    70.7
78   Oak Hill East   70.7
80   Kiawah Island Ocean   71.0
81   Casa De Campo   71.7
82   Cape Kidnappers   72.0
82   Inverness   72.0
82   Muirfield Village   72.0
85   Los Angeles North   72.7
86   Bandon Dunes   73.0
87   Cal Club of SF   77.0
88   Olympic Club   77.3
89   Bethpage   78.7
90   Whistling Straits   80.3
91   Shinnecock    80.7
92   Rock Creek Cattle    81.0
93   Peachtree   82.0
94   Oakmont   83.0
95   Diamante Dunes   84.7
96   Nine Bridges   87.0
97   Ellerston    94.0
« Last Edit: November 21, 2021, 01:17:19 PM by Kalen Braley »

Tom_Doak

  • Karma: +2/-1
Kalen:


The numbers for Cape Kidnappers looked off to me, because the whole course is on a gentle tilt and there is not a lot of climbing involved. 


After reviewing Jeff's raw data, I've decided the site he uses doesn't use the bridges we built, but measures the walk down through the ravines on holes 6, 8, and 14.  That would add some serious exercise to the round!  I know for sure because we played it that way early on during construction.

Kevin_Reilly

  • Karma: +0/-0
SF Club's uphill walks are on #2 (approach) and #8 (entire short hole), and both of those are easy.  Overall, the course is an enjoyable walk.


So keep that in mind when viewing the above rankings....the numbers don't always tell the story.
"GOLF COURSES SHOULD BE ENJOYED RATHER THAN RATED" - Tom Watson

Kalen Braley

  • Karma: +0/-0
Kalen:

The numbers for Cape Kidnappers looked off to me, because the whole course is on a gentle tilt and there is not a lot of climbing involved. 

After reviewing Jeff's raw data, I've decided the site he uses doesn't use the bridges we built, but measures the walk down through the ravines on holes 6, 8, and 14.  That would add some serious exercise to the round!  I know for sure because we played it that way early on during construction.

Tom,

I would agree in principle that the data seems it could use some due diligence.

For example, the website shows Cypress Point's max elevation at 52 meters or 170 feet.  But using Google Earth, the highest point I can find on the actual course is 141 feet between 5 green and 6 tee, (nearly 10 meters less).   And I confirmed this on the USGS site.  You know the property pretty well, is there a higher point I'm missing?

That being said, i'd guess if you had a 400+ yard hole that rose 10 meters from tee to green in gentle fashion, most people would probably grossly under-estimate the actual rise, especially if there were other far-off features to disguise it.

Kalen Braley

  • Karma: +0/-0
SF Club's uphill walks are on #2 (approach) and #8 (entire short hole), and both of those are easy.  Overall, the course is an enjoyable walk.

So keep that in mind when viewing the above rankings....the numbers don't always tell the story.


Agreed Kevin,

The elevation gain is only 1/3 of this ranking, as total distance walked and the % difference of green to tee walks is the other 2/3rds.  I'd certainly be in favor of using other criteria and/or a weighted system to paint a more interesting picture.

P.S.  I would be surprised by Shinnecock, but all those Open tees push it far down the list with all the extra distance.

Joe Hancock

  • Karma: +0/-0
That being said, i'd guess if you had a 400+ yard hole that rose 10 meters from tee to green in gentle fashion, most people would probably grossly under-estimate the actual rise, especially if there were other far-off features to disguise it.


Kalen,


Those numbers are approximately the equivalent of 2.5% grade, or in other words, pinnable grade on greens.
" What the hell is the point of architecture and excellence in design if a "clever" set up trumps it all?" Peter Pallotta, June 21, 2016

"People aren't picking a side of the fairway off a tee because of a randomly internally contoured green ."  jeffwarne, February 24, 2017

Tom_Doak

  • Karma: +2/-1
Kalen:

The numbers for Cape Kidnappers looked off to me, because the whole course is on a gentle tilt and there is not a lot of climbing involved. 

After reviewing Jeff's raw data, I've decided the site he uses doesn't use the bridges we built, but measures the walk down through the ravines on holes 6, 8, and 14.  That would add some serious exercise to the round!  I know for sure because we played it that way early on during construction.

Tom,

I would agree in principle that the data seems it could use some due diligence.

For example, the website shows Cypress Point's max elevation at 52 meters or 170 feet.  But using Google Earth, the highest point I can find on the actual course is 141 feet between 5 green and 6 tee, (nearly 10 meters less).   And I confirmed this on the USGS site.  You know the property pretty well, is there a higher point I'm missing?

That being said, i'd guess if you had a 400+ yard hole that rose 10 meters from tee to green in gentle fashion, most people would probably grossly under-estimate the actual rise, especially if there were other far-off features to disguise it.


Kalen:


Yes, a long gentle climb works out to a lot of elevation.  The best example I can think of is the 3rd hole at Rock Creek, which looks pretty flat; most people think the climbing starts on #4.  In fact, that hole climbs 3% over 570 yards [1900 feet], which works out to nearly 60 feet!


I don't have a topo map of Cypress Point, but I checked Google Earth and found the same numbers you did.  I thought you were talking "elevation difference" and maybe part of the issue was the "walk" going to zero when players hit over the ocean on #16, but you were talking about the highest point, which is indeed #5 green and the next tee [but only barely higher than #8 tee].

Kalen Braley

  • Karma: +0/-0
Correct,

I was speaking overall to the issue that any of the numbers could be suspect based on this one data point that I randomly checked.

Going back to this example, if you look at the Elevation profile section in the included link,  it lists 52 meters as the highest point on the course, but that's two of us now who can't find anywhere near that.

https://www.provisualizer.com/courses/cypresspoint.php

As for the other issue, it does seem plausible that a course with lots of gentle slopes like a Merion or CP could add up to a significant amount of uphill walking over 18 holes, even if it feels relatively flat overall.

Paul Rudovsky

  • Karma: +0/-0

Jeff--


Paul thanks for chiming in.  If there is a list guy I know it is you! ;D


For your first question. I heard back from Provisualizer that the green to next tee IS as the crow flies and a lower end estimate. So in many cases the distance and total ascent are low estimates and with some courses the transitions are substantial. So with this information it identifies a limitation of the data, that although the same for all, it isn't actual and at the low end. How much it varies for some courses (TPC Sawgrass) vs. TOC for example are considerable. Also the tee boxes are always the back one, which normal golfers don't use.


The second question is interesting and agreed that it could be that downhill walking is more rigorous than level. I don't know the answer to that and welcome others opinions. If that is the case, yet another complexity.


Jeff--


Thanks.  Do not worry about the additional complexity (easy for me to say  :) ).  Seriously, things like this almost always require several iterations before they work out the kinks and become really useful and interesting...but you can never get to that point without the starting/pioneering work like you have done.  The key is to take the issues one at a time (dealing with the most important ones and relatively easily solved ones first) and take the process a step at a time.  When the first personal computers were released about 40 years ago...you couldn't even balance your personal checking account on them...the data requirements were too large for the storage capacity of those "revolutionary" machines.  Do NOT get discouraged...this is potentially extremely interesting and needs to be refined step by step.

Jeff Schley

  • Karma: +0/-0
Dear anyone who is interested.  Kalen and I are doing to do a zoom session with the Provisualizer owner Simon this coming Saturday at 11 am EST. He is going to demonstrate how he maps a course. He will be doing Cypress Point and Merion as those are the most discussed thus far. I asked if we could have several more people and he said sure. So I have spots for 6 additional GCA posters who maybe interested to attend. PM me and I'll send you the zoom link. I'm pretty fascinated by this technology and like others here want to learn the strengths and weaknesses of the information being given. 
"To give anything less than your best, is to sacrifice your gifts."
- Steve Prefontaine

Mike_Trenham

  • Karma: +0/-0
Dear anyone who is interested.  Kalen and I are doing to do a zoom session with the Provisualizer owner Simon this coming Saturday at 11 am EST. He is going to demonstrate how he maps a course. He will be doing Cypress Point and Merion as those are the most discussed thus far. I asked if we could have several more people and he said sure. So I have spots for 6 additional GCA posters who maybe interested to attend. PM me and I'll send you the zoom link. I'm pretty fascinated by this technology and like others here want to learn the strengths and weaknesses of the information being given.


Could it possibly be recorded and shared as long as no trade secrets are revealed?
Proud member of a Doak 3.

Jeff Schley

  • Karma: +0/-0
Dear anyone who is interested.  Kalen and I are doing to do a zoom session with the Provisualizer owner Simon this coming Saturday at 11 am EST. He is going to demonstrate how he maps a course. He will be doing Cypress Point and Merion as those are the most discussed thus far. I asked if we could have several more people and he said sure. So I have spots for 6 additional GCA posters who maybe interested to attend. PM me and I'll send you the zoom link. I'm pretty fascinated by this technology and like others here want to learn the strengths and weaknesses of the information being given.


Could it possibly be recorded and shared as long as no trade secrets are revealed?
Hi Mike. He said he could have a second session if needed down the road. I'll also ask him about the recording.  Good idea.
"To give anything less than your best, is to sacrifice your gifts."
- Steve Prefontaine

Bryan Izatt

  • Karma: +0/-0
The Provisualizer site looks neat and I'm impressed that he has mapped my home courses in Canada.  However, I'd take the elevation data with a large grain of salt.


On my home course I checked the elevations for the first couple of holes that have some significant elevation changes and Provisualizer doesn't capture a 60 yard wide swale that is 2-3 meters deep.  It also underestimates a fairly abrupt 10 meter rise on the second hole.  I think this results from the inherent limitations of the SRTM 1 arc-second data.  It is only accurate to somewhere around +/- 5 meters, there are anomalies in the data, and its resolution horizontally is around 30 meters. All of these make it questionable for such micro applications as elevation changes on a golf course.


Vis-a-vis Cypress Point I also couldn't find a high spot of 52m except in the trees next to the maintenance area by the 4th hole.  I'm also skeptical of the minimum elevation of 2m - that's just about 7 feet above sea level.  As an exercise I charted a path around CP on Google Earth and did the elevation profile (see below, some scrolling to the right required).  The total distance was close enough.  The min and max elevations were 5m and 44m as you can see in the two text bars above the graph.  The total ascent came out at 186m which is significantly more than the Provisualizer's 152m. I'd guess that they are using the Google Earth data to do their calculations so you could ask him what could account for this discrepancy.  I've never played CP, so it's hard to say if either method gives an accurate account of the elevation changes. 


My home course comes in with about the same ascent total as Merion.  I've seen Merion from the road and I know my home course and I am very certain that my home course has substantially more ascent than Merion, hence the large grain of salt vis-a-vis Provisualizer elevations data.



Kalen Braley

  • Karma: +0/-0
Bryan,

Really like what you've done there.  Looks like you used the Install version of Google Earth to get that functionality, I may need to download it again, as I've only used the web version for the last few years.

P.S.  Provisualizer claims they use the USGS Elevation Point Query Service for elevations.

Jeff Schley

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Bryan good info.....


Provisualizer doesn't use Google Earth data at all. They use SRTM data for the profile section which gives the Total Ascent and min/max elevation. However this INCLUDES green to tee transitions (GTTT) for both walking distance and total ascent. This doesn't include any points other than where the ball lands. So if you tee off from X elevation and your shot lands -5m below that, they don't calculate the down and up you may walk to your ball. It is only based on where the ball lands in relation to where you hit from, then the GTTT as well.
Regarding the elevation given on the 2D/3D Planner, in the United States this is actually based on the USGS National Map Elevation Point Query Service (EPQS): https://nationalmap.gov/epqs/  This is supposed to be a better data set and more accurate. However isn't what is used for the course profile data, that is the SRTM. It is one question I want to ask Simon, why can't they use the EPQS data for the profile since it is more accurate?  We shall see.
"To give anything less than your best, is to sacrifice your gifts."
- Steve Prefontaine

Kalen Braley

  • Karma: +0/-0
Jeff,

If you look at the email from Sunday afternoon, they indicated they don't use the EPQS data because it would put a heavy load on the USGS server and they don't want to get black listed.  Whereas the STRM data is hosted on thier own servers, so they can do what the like.

Seems like they could download the EPQS data to thier website as well, but I'm not sure what that would entail to do that.

Kalen

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