Please help answer this question for me: What breaks more -- slow greens or fast greens?

Thanks in advance,
Matt Walsh
PGA Head Professional
Cape Cod National

Dear Matt,

Fast.

Gravity is a force that pulls the ball straight towards the middle of the earth. On a flat and level surface, the green cancels out gravity equally beneath the ball so the ball does not tilt in any specific direction downhill. Once the green tilts, the ball's center of gravity also tilts "downhill." The LESS the grass downhill interferes with the ball's heading downhill, the more the ball "breaks." Tall or lush grass keeps the ball more suspended against the tilt downhill. A faster, slicker surface means that the grass resists the ball's tilting and rolling "downhill" less, so the ball breaks more.

All "break" is a combination of degree of surface slope and green speed and rolling speed of the ball. The slower the ball, the more severe the break. The more severe the slope, the more severe the break. The less friction in the surface (faster green speed), the greater the break. Any specific breaking of the ball is a combination of these three factors.

Thanks for asking!

Cheers!

Geoff Mangum
Putting Theorist and Instructor
Geoff Mangum's PuttingZone
http://puttingzone.com
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Hi Geoff

This an interesting topic, it seems so intuitive and yet the more one thinks about it the more the room for confusion.

For instance. Applying the above factors to an uphill breaking putt vs. a mirror image downhill breaking putt would suggest that the uphill put would break less because the ball is travelling faster initially and less influenced by the break. But how do you factor in gravity and its tendancy to straighten out a downhill putt and tighten the radius on an uphill breaker as the speed of the ball drops?

I think most of us probably think we have a feel for how much break to play but are totally oblivious to the science behind it----probably at the expense of our ability to properly judge the amount to borrow on a breaking putt.

I'm sure you have probably covered this somewhere but if you wouldn't mind providing some comments or links it would be greatly appreciated.

James

Dear James,

The least confusing way to think about the different way uphill and downhill putts break is to simplify the thinking about uphill and downhill. The underlying assumption that both uphill and downhill putts are the same "green speed" may be literally true, but not very helpful when it comes to comparing breaks on an uphill putt to a hole and a downhill putt to the same hole. Viewing the matter this way, the uphill putt gets "hit faster" and the downhill putt gets "hit softer" -- but that's not the best way to think about uphill-downhill.

A simpler way is to view ALL putts as not only STRAIGHT but also FLAT AND LEVEL. That way, a 15-foot uphill putt to a hole and a 15-foot downhill putt to the same hole are simply two 15-foot putts, but the uphill putt is slower and the downhill putt is faster in comparison to a truly flat and level putt on the same green. Once the uphill-downhill putts are viewed as "slower" or "faster" surfaces than otherwise, the breaks don't directly compare. The uphill putt breaks like a putt on a slower surface in comparison to the break of a downhill putt.

Take two putts for example: a right-to-left (righthander) uphill putt from 5 o'clock with the fall-line straight uphill-downhill being the 6-12 line on the clockface, compared to a downhill putt breaking right-to-left from 1 o'clock. The 5 putt is over a slower surface, and so gets hit "harder" (faster) to begin with and dies out more abruptly. The break over the first two-thirds or more of the putt is minimal due to the speed, but sharpens up at the end as the slower surface brings the putt to a short, quick conclusion. Coming down from 1, the putt has a gentler speed over the "faster" surface and so breaks more over the first two-thirds or more of the putt and the final stopping section of the putt also has gentle breaking.

So, in my view, understanding the break differences going uphill versus going downhill on the same green is not really comparing apples and apples, but is more akin to comparing apples and oranges because the two putts don't have the same green speed surfaces.

Of course, the two putts are on the same green speed, but the energy differences of the elevation of the ball at the start and at the end of the putt is what makes the two putts require different forces for the putts over the same differences. The change in elevation is what really matters for getting the touch right, but when comparing two putts with the same elevation change and total distance (one uphill and one downhill), it is best to regard the two putts as flat and level but on differing green speeds.

To get this pretty accurately, all that is required is to note intuitively that the uphill putt is "slower" than usual and the golfer has to "get the putt all the way to the hole," whereas the downhill putt is "faster" than normal and the gofer needs to putt the ball "only as far as the hole and no farther." The intuition does a great job in adjusing on this simple basis.

Cheers!

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

Over 1,095,000 visits and growing strong ...

518 Woodlawn Ave
Greensboro NC 27401
336.790.8176 home
336.340.9079 cell

This is an interesting study of the differences of uphill-downhill putts on fast vs slow surfaces. The investigator compared a Stimp 8 surface (average) against a Stimp 14.5 surface (very fast). Are you inclined to putt?. The conclusion of the study is that fast surfaces require a wider range of adjustment from uphill putts versus downhill putts the same distance -- uphill putts have to be hit faster and downhill putts have to be hit slower and the difference between these putting velocities is greater than the difference on a slower green.

For what it's worth, I think this mean one has to be very careful adjusting for uphill-downhill on a fast surface, and that the difference is not that great on slow greens.

Cheers!

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

Over 1,095,000 visits and growing strong ...

518 Woodlawn Ave
Greensboro NC 27401
336.790.8176 home
336.340.9079 cell

That makes sense to me. I belong to a club that allows me reciprocal play at a number of other clubs. Greens are generally in the 9 to 11 stimp range but there are times when I find that a course will have greens that seem to be fast downhill but slow uphill. This always seemed strange to me. Perhaps your above conclusion is an explanation for this, in that the green is a tad faster than I am used to and the difference in the relative speed of uphill vs downhill is greater and therefore more noticable.

Thanks again Geoff. Left to my own devices it would take years to come to these conclusions and then only after a series of false conclusions.

James