Geoff,

Just got finished watching Michele Wie play in the U.S. Juniors, she got beat by Morgan Pressel 3 and 2....I got to thinking on one hole, as everyone is coming up short, about elevation changes and how it effects club selection...I forgot to have you show us how to figure out a putt going uphill and across a an elevation change...Also, you being a former greenskeeper, do you know where I might be able to get information on how to figure out club selections due to the amount of elevation change on a hole...For instance, for every 10 feet of elevation, use one more club...There must be a source where someone has charted this information out...Of course, weather conditions also has an effect...

Regards,

Bob Montello

Dear Bob,

Figuring putts uphill / downhill obviously depends on both slope or incline and green speed. Generally, most slopes are somewhere between 2 and 5 percent grade, and most speeds for tournament play are 10+ on the Stimpmeter. Taking a 10 green with a 3 % slope (3 feet of rise for 100 feet of run), the extra energy required is the energy needed to lift the ball from the starting elevation to the end elevation. A 100 foot putt must raise the ball three feet higher than its beginning, in addition to the energy of a 100-foot level putt. How much is that? Since a Stimpmeter is how far a ball rolls after being raised one foot high, then 3 feet high is 3 times the green's Stimp. So, for a 100-foot putt on a 3% green Stimping 10, you have the equivalent of 100 feet plus an extra 30 feet of putting energy for raising the ball 3 feet. A 100 foot putt is then equivalent to a 130 foot putt. Treating a 100-foot uphill putt on a 3% Stimp 10 green, then, is the same as making a 130-foot level putt.

Another (shorter) example: A 33 foot putt raises the ball 1 foot on a 3% green, so that takes 1 Stimp distance extra (10 feet) in energy. So a 33 foot putt uphill 3 % on a Stimp 10 green plays likme a 43 foot putt.

Another (shorter still) example: A 10 foot putt raises the ball a little less than 1/3 as high as a 33 foot putt on a 3% slope, so that is about 1/3 a Stimp distance, or 3.3 extra feet on a Stimp 10 green. So a 10 foot putt plays like a 13 foot putt.

So the formula for extra feet to add to the distance, for every 10 feet of putt, is Slope * Stimp / 10. A 2 % slope on a 9 Stimp needs 2*9/10 = 18/10 = 1.8 extra feet. You'll find that 10% to 20% more distance is a good rule of thumb for most cases. Treat a 10-footer uphill as a putt of 11 or 12 feet, and this is pretty good on most slopes and Stimps.

Perhaps the simplest way to think of it is that since most greens Stimp between 8 and 12, and one Stimp distance is for 12 inches of height, just ball-park all greens at Stimp 12. This makes the math figuring real easy: 1 foot of extra putting energy for each 1 inch of rise. So a rise of 2 inches over 10 feet is just 2 feet extra, a 12-foot level putt.

Downhill is simply the opposite -- subtract the extra distance due to the ball dropping. A 3 % 10 green on a 100 foot putt downhill drops 3 feet, so it has 3 Stimps worth of help from gravity, or 30 feet, so a 100 foot putt downhill on this green is really like a 70 foot putt.

Another way to view the matter is that for every 100/Slope feet, add or substract one Stimp distance. On a 4 % green, add or subtract one Stimp for every 25 feet. On a 2% slope, add or subtract one Stimp distance for every 50 feet.

This is the mechanical way of viewing the adjustment for uphill / downhill. The instinctive way is more intuitive. Just say to yourself "roll the ball all the way to the hole" and if uphill, say "add enough to get there," and if downhill, say "only roll it so far that the downhill slope carries it all the rest of the way to the hole."

There are some combinations of slope and Stimp that the ball will not stop on once it starts rolling downhill. Usually, greenskeepers are supposed to avoid these combinations in locating the pin, so that any putt to the pin has a fair chance of stopping within 2-3 feet of the hole.

As far as club selection to elevated or depressed greens, the subject is covered in Frank Werner & Richard Grieg, How Golf Clubs Really Work and How to Optimize Their Design, chapter 13, pp 59-61 (2000). Basically, the rule of thumb depends upon how far the golfer hits the clubs and with what trajectory. They write: "We conclude that for typical greens, the rule of one-step difference for a 10 yard elevation or depression is probably good advice." This advice takes into account the fact that mostr greens are slightly sloped towards the fairway, thus reducing bounce and roll. For flat greens elevated or depressed, their data really suggests a rule nearer 20 yards.

Cheers!

Geoff Mangum
Putting Theorist and Instructor
The PuttingZone
http://puttingzone.com
Golf's most advanced and comprehensive putting instruction.

Over 45,000 visits mothly and growing strong ...

Dear Bob,

Here are two BRAND NEW approaches to handling elevation changes in a putt.

FIRST APPROACH: Add/Subtract a % of Putt's Length

This past week I was teaching in Cleveland with my friend David Grant Geier's school, Golf Inside-Out, [http://www.golfinside-out.com] and he and I developed the physics and the formula for balls going up or down the green slope. I'll spare you the mathematics, because it all simplifies to this:

To figure an adjustment plus or minus for uphill or downhill putts as a percentage of your present length, the formula is Stimp * Slope.

For example, you are putting to a target uphill 10 feet away on a green that Stimps 10 and has a 3% Slope (i.e., it rises 3' for every 100 feet of run, which is the same as 3" rise for every 100" or every 8.33 feet). The Formula is 10 x 3 = 30%. So add 30% to your putt length of 10 feet (add 3 feet), and make the putt as if it were a 13 foot level putt.

Going down, just subtract. A 10 foot putt then becomes a 7 footer across level ground.

CAVEAT: This system is only for putts that go uphill or downhill and not for putts that go uphill and then downhill. As for putts that go uphill and then downhill, the Formula works only for the uphill section of the putt. Or at least that';s what my thinking is right now.

You have to pretend you are putting across level green. Otherwise, you might compound the "get it there" notion with the extra length, and blow the putt by the target. So level your shoulderframe to the slope of the green and forget the fact that the putt is uphill. This is a bit of a trick, since your vision and inner ear sense of balance gives conflicting info to say you are still putting uphill, but you have to suppress that info by pretending the green is level.

In general, given the typical green speeds and typical slopes, adjustments are usually in the 25% to 35% range. On very fast greens (Stimp 12), with lots of Slope (eg, 8%), the downhill adjustment is a whopping 96% of the length of the putt. So a slick 10-foot downhiller on such a slope would require that the golfer roll the ball a mere 4% of the total 120 inches, or about 5", and that's all! Going up, the golfer would be looking at stroking a 10 footer as if it were a 19.6 footer, but remember that it's not too hard to do that on a Stimp 12 green. Even so, the putterhead speed at impact will be about twice what it would be otherwise.

SECOND APPROACH: Alter Your Tempo

Every golfer ought to have one and only one tempo for every putt. Mine is about 60 beats per minute or one stroke per second. The stable tempo is the foundation for distance control. But uphill / downhill is really an energy adjustment, not a length adjustment -- or so it can be viewed. Altering your tempo coming down from the top of the backstroke will alter the energy of the putt. Quickening the pace of your normal stroke will add distance, and slowing your pace coming down will reduce distance.

So, facing an uphill 10-footer, if you treat the 10-footer as a level 10-footer, your targeting and tempo ought to be short. But if you treat the 10-footer as level but quicken your pace, the putt will get there even though you target as if the putt is 10 feet across level ground.

At this point, I'm not sure just how much quicker translates to Slope. The Touch system has already taken Green Speed into account for all level putts, and the Targeting of the head turn doesn't change for uphill / downhill touch calibration, so something else has to get into the mix. This Tempo change appears to work quite well, even if it is only an intuitive quickening or slowing of the downstroke.

I'll keep working on this approach and try to get it fine-uned a bit.

Cheers!

Geoff Mangum
Putting Theorist and Instructor
The PuttingZone.com
http://puttingzone.com
Golf's most advanced and comprehensive putting instruction.

Just discovered your site, and love the range of material.

In the Forum discussions of Stimpmeter and Uphill/Downhill adjustments, two questions:

1. In the Slope * Stimp / 10 formula, the result would be lower stimp equals smaller adjustment (which seems opposite to reality). Eg, your example of Sep 11 2003 for a 10-foot putt, a 2% slope at stimp 10 would play like a 12-foot putt (2 extra feet). However, a 2% slope at stimp 9 - a slower green - would play like an 11.8-foot putt (1.8 extra feet). Shouldn't the formula be Slope * 10 / stimp? This would yield, for a 2% slope at stimp 9, an equivalent 12.2-foot putt.

2. In the June 30 2004 stimpeter physics discussion, you mention Arthur Weber's use of 12.6 inches for the height at which the ball is released (end of 36-inch ramp), and re-do his calculations for the 10.6-inch height (actual 30-inch point of ball release). Since your "Two Newly Discovered Approaches" data was based on "how far the ball rolls after being raised one foot high," shouldn't the uphill/downhill formula be adjusted for that difference -- ie, 12 / 10.6 = 1.13.

In that case, for the above examples:

2-degree slope, stimp 10, 10 foot putt = 2 * 10 / 10 * 1.13 or 2.26 extra feet or 12.26 equivalent putt distance up hill, 7.74 downhill

2-degree slope, stimp 9, 10 foot putt = 2 * 10 / 9 * 1.13 or 2.51 extra feet or 12.51 equivalent putt distance, 7.49 downhill

A new fan,
Rick

Dear Rick,

No and yes.

To answer 1: You have to remember that your "pretend" adjusted putt is as if across a level green. A 12-foot putt across a Stimp 10 green SEEMS like a bigger putt than an 11.8-foot putt across a Stimp 9 green only because of the length, but it's not bigger in terms of the backstroke. The Stimp 9 putt takes a bigger backstroke to travel 11.8 feet than the Stimp 10 putt requires to roll the ball 12 feet. In the instinctive approach to touch, the brain handles the setting of the backstroke at a non-conscious level, but the backstroke that results takes into account your appreciation of the green speed. The Stimp 9 putt IS a bigger stroke and a faster putter head at impact, imparting more initial energy to the ball, but the green friction only results in the ball rolling 11.8 feet. The Stimp 12 putt is a comparatively smaller stroke with a slower putter head speed at impact, imparting less initial energy to the ball, but the green friction is less and as a result the ball rolls 12 feet.

To answer 2: You are correct that a Stimp corresponds to 10.6 inches in elevation change and not "a foot" as I have written, and I need to adjust my approach to reflect this. For example, a 3% slope rises 3 feet over a run of 100 feet, but this is not the equivalent of 3 Stimp distances, but is more than that: 36" / 10.6" = 3.4 extra Stimp distances. That is as you say 1.13 times larger adjustment (13% more) than I have written above.

Thanks for the help! Much appreciated.

Cheers!

Geoff Mangum
Putting Theorist and Instructor
Geoff Mangum's PuttingZone
Golf's most advanced and comprehensive putting instruction.

Over 825,000 visits and growing strong ...

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Bob,
Check out probablegolfinstruction.com. Ken Tannar is a British Columbia high school science teacher who has calculated adjustments for uphill/downhill shots, wind, etc. For a small fee, he can send you precise adjustments for your personal carry distances for each club.
Rick