I was wondering if you could lead me in the right direction towards reading greens. Especially how to determine the way the grain runs(toward the water. etc...) I have a tremendously hard time trying to figure that out.
I am currently writing a multipart series on green reading for NBC Sports' Golf.com, and I will send that to you when it is done.
In the meantime, here is the gist of the subject:
RE GRAIN:
Grain is not too much of a concern on Bent greens, due to the growth pattern of the blades and modern mowing / verticutting practices. On Bermuda, it's still a problem.
The general rule is if you face the sun and the grass looks dark, you are seeing the shadows of the blades as they point in your direction, so the grain runs toward you. If you see the shiny back of the blades as they lay curved away from you, the grain is running away from you.
Most grain runs towards the path of the sun. In our northern hemisphere, the sun typically crosss the sky a bit south of us east to west. The sun has its greatest effect after it has been shining a while, so most grass heliotropism (following the sun)is more towards the setting sun later in the day than in the morning. This is generally southwest.
Sometimes the grain follows the drainage pattern of water flow, sometimes the prevailing wind (if there is a steady prevailing wind like at the seashore or the plains), and sometimes it gets conditioned with mowing patterns as the rollers and blades keep training it one way or another.
If the grain is following the water flow, it may run towards local lowspots like ponds, creeks, oceans, etc. But more normally it follows the sun. Wind, water, and mowing are external forces at work to train the grass blades, whereas following the sun is an internal effect from the structural growth of the blade itself. So any external effect overcoming this internal effect generally needs to be ppretty substantial and very steadily applied. So, usually, go with the sun's path across the sky especially in the afternoon, and really, you have to look at the shiny-versus-dark aspect.
When greenskeepers mow stripes into a green, the stripes run in opposite directions each lap. One stripe is dark and one is light. That's because the roller and blades created a little grain for that stripe. This sort of grain is usually not much to worry about.
Grain may not be the same all over the green. There is frequently a patchwork of different grain directions, like a quilt effect. You just have to look.
During the day, the grass grows, so late in the day the grain is probably worse than earlier. The shaggier the grass the more the grass tips impact the roll of the ball in opposing the roll or guiding it off in the grain direction. However, such greens are also slower, so you putt the ball a bit faster to cover the ground and this reduces the effect of grain a little. But when the ball is slowing near the hole, late-day grain can be a doozy.
RE GREEN SLOPE READING
The green must drain or the grass won't grow. In order to drain, the green needs a slope of at least 2 percent drop in elevation from the highest point to the lowest. Under the surface, drain pipes collect the water and port it out from under the green. The subsurface generally is contoured the same as the putting surface for support. A typical green has 3 percent as a general or avergae overall slope, with areas of more or less slope. Once the slope gets up around 10 percent, depending upon green speed, the ball will not stop since the tilt gives to much pull of gravity to allow the ball to settle into the grass tips. SO -- the general range is between 2 and 10 percent slope.
Most greens have one general overall slope, but some have "lobes" that drain in different directions. There is still an overall slope but the lobes run the water off to the side of this overall slope (sometimes even to the top), where there is a collection area beside the green. Under this area is a pipe system that ports the off-green collection water back to the general drainage flow of the hole or fairway.
SO -- the green is built into the overall terrain's drainage pattern. The overall slope of the green generally matches this overall drainage pattern of the layout, with the exception of these lobe designs with greenside collection areas.
From our geography classes about landform processes, we learn about the constant processes of wind and water erosion in shaping the landscape or terrain. Mountains are rocks cast upward by continental forces, but they are worn down by wind and water over the eons. Surface water always runs downhill, collects in creeks, heads to streams and rivers, and eventually flows to the ocean. The continental divide marks the part of the landmass where water flows away in basically different directions.
So, in any golf course setting, the green is sited in the general terrain. If the hole has the green elevated above the fairway from the approach shot, chances are pretty good the green slopes back down to the fairway, since the green is sited on a hillside draining back to the fairway. If the green is sited with the highest part of the local terrain to the left and drainage features like creeks, ditches, ponds, etc. to the right, chances are that the green slopes overall left to right. If the green is lower than the approach, then the question is whether there is water between the approach fairway and the green. This would indicate that the local terrain bottoms out before the green and then starts rising again on the other side of the creek or pond. Hence, the green would probably be tilted to the water and the fairway, even though lower than the approach fairway. If there is no intervening water (or drainage ditch or furrow) between the fairway and the green and the green is lower than the approach, chances are the green slopes away from the fairway.
In every case, the need is to identify the basic overall drainage pattern of the terrain. This usually means locating how water from the green area would leave the hole as it seeks the sea.
The principal rule of thumb is: greens slope away from mountians or hills and towards creeks, ponds, lakes, rivers, or oceans.
The complication comes from lobes with different drainage patterns; greenside bunker mounding to channel water away from the bunker so it won't wash out; and architects who build in hard-to-detect slopes at variance with the general terrain.
I've mentioned lobes already. If you have a greenside collection area (depressed bowl with a drain-grate in it), it will not be downhill in the same overall draiange direction but off to the side or seeming to run contrary to this pattern. Look at the green to see if there is an area of the green that seems to channel water into this direction. Chances are there is a drainage pipe underground that sends the green water to the collection area, and then another pipe there turning the collected water back into the overall drainage direction.
Greenside bunkers get washed out if the green allows water to run off into the bunker. That is, the sand gets floated out of the trap and is lost. The sand costs money, and washouts have to be repaired with time and money EVERY TIME there is a serious rain. The obvious solution is to not locate bunkers in the way of the drainage flow, OR if you have to do that because of making the hole challenging or interesting, at least protect the sand from the drainage with a diverting mound on the green surface. Almost all bunkers in the drainage direction have this sort of mounding. Because of this mound on the green, the surface right around there tilts back uphill or away from the bunker. So this rule is: near a bunker with protective mounding, the green slopes away from the bunker in that immediate area.
Some architects try for optical illusions to make green reading more challenging. Typically, this involves greens perched on a hillside or on top of a local hill in a surrounding layout where it seems the green ought to follow the local drainage direction, but the hilltop or hillside perching has allowed the architect to play with the local drainage direction. This is especially potent in mountain country, where the mountains and streams seem to signal the overall drainage with vivid clarity. If the architect is playing this game, the green will not slope very much uphill, because if it did then the illusion would not work. So the rule is: when there is a strong overall drainage pattern from surrounding landforms, but the green seems to be perched on a local feature that could allow green drainage at variance with the overall direction and the green's slope is not pronounced, be careful to assess the slope.
A trick is to look for the green's lowest and highest points. If the green slopes back to the fairway, and is a 3 percent slope, and is 100 feet from front to back, the change in low to high points will be three feet. This means you can crounch at the lowst point so your eyes are three feet above the ground and then your eyes would be level with the highest point of the green 100 feet away. You can crounch at the lowest point of a green and estimate the overall slope by guestimating the elevation change 100 feet uphill. Two feet is 2 percent. Five feet is 5 percent. Etc.
A variant on mountain greens is the green that hardly slopes at all, even though the surrounding terrain slopes like crazy. In this visual setting, the green "looks" like it slopes more than it does because of the influence of the local scenery. The green might well slope in the same general direction as the terrain, but much less so. These greens require you to isolate your perceptions to the green in relation to your balance and the zenith of the sky, rather than to your sense of visual tilt. In effect, you have to ignore a lot of what your eyes tell you.
Once you have taken in the general lay of the land (and this is often best done from the fairway), then you need to assess the green's siting in the overall layout. For this you need a reference to a true vertical, like a surveyor's plumb bob. Western society is generally "rectilinear" in its buildings and other manmade features. So you can use nearby buildings to get a sense of the true vertical. A house beside the course has a vertical line up the corner and often the chimney is a good strong vertical line in the sky. Communications towers are erected and stabilized in a vertical orientation, so these very tall features are often available. Trees, power poles, and lamp poles are usually NOT reliable because verticality is not that great a premium for them.
The flag in the green is supposed to be seated vertical to the earth and not the surface tilt, but the flag is not always seated correctly by the greenskeeper (this I know, trust me) and in any event gets changed during the day by handling and by winds whipping the flag pole. However, if you need it, you can lift the flag out of the cup an inch or two and let the base of the flag dangle like a plumb bob directly over the hole and then drop the flag back into its seat in the bottom of the cup. Watch the flag pole. If it stays the orientation it had just before you dropped it, it is probably correctly seated and vertical. If the flag pole goes in the cup's hole and then wanders out of the plumb bob orientaion, tilting to one side a bit, that means the flag is not properly vertical and the cup is cut askew into the green.
Another true vertical is suspending your putter so it hangs straight. This often means making sure the toe is pointed the same way you're looking. Let me emphasize that this use of the putter is NOT to get a read on the break -- it's just to have a vertical to gauge the green's overall slope. You can look in any direction or several directions around the green with this reference to assess the green slope. You can also hang the shaft so that it slices through the image of the hole (a dark oval shape) and try to assess whether the oval tilts in any particular direction downhill. Again, this is not plumb bobbing for read (I don't believe that works) -- it's just using a true vertical of the shaft as a visual ruler to get a better look at features of the green.
By the way, the hole is supposed to be cut to the earth, not flush into the surface tilt. You check this with whether the flag is aimed to the zenith in the sky and is perfectly upright with respect to gravity. If the hole is cut to the earth, the RIM of the hole will look like a tilted circle on the surface. If you tilt a circle, it will have ONE ND ONLY ONE highest point and one and only one opposite lowest point. Identify this highest point on the tilted rim and you can see immediately what the uphill-downhill line through the cup is -- it runs from the lowest across the center of the cup out the highest point. This is the same as the "fall line" at the cup.
You have NO break only when your ball is located exactly on this fall line either above or below the hole (pretty rare, but it happens). If the tilt between your ball and the hole is constant (no other undulations in the green between the two), then you can gauge the slope and break in this way using the fall line: the maximum break will be if you are off to the side of the fall line so a direct line to the hole is perpendicular to the fall line. If you stood at this "hole high" spot the same distance away as your putt and imagined a perfect putt speed aimed straight at the hole, the ball would miss low and cross the fall line a certain distance below the hole (say 10 inches). If you aimed this putt 10 inches ABOVE the hole, it ought to go in. Now here is the neat part: For ANY putt of the SAME length across uniformly tilted surface, no matter where the ball is located in reference to the fall line (on it, off to the side, perpendicular to it... doesn't matter) -- this "aim spot" above the hole you identify by the side-on imaginary putt is exactly the same aim spot for any putt of the same length.
This little trick works regardless of green speed so long as you are pretty accurate in imagining the break of the imaginary side-on putt and you have identified the lay of the fall line correctly.
The other rules for reading putts (not just reading the overall lay of the green) include:
putts uphill run faster at first and so cover a lot of ground with less break than might otherwise take place, although uphill putts slow down faster too, so they tend to break a bit sharply at the very end.
putts downhill need to go more slowly and so tend to take the break more, but they also don't slow and stop very dramatically, so there is not often much sharp curving at the end. In addition, since the aim spot is above the hole and on the same side of the hole as the ball, the "fall line" pull of gravity tends to help direct the ball to the hole, in a sense that it does not help with an uphill putt. because of this, downhill breaking putts can be viewed as easier than uphill putts so long as the speed is managed astutely.
a 10-foot putt on a medium fast green surface (average, about 8 on the stimpmeter) on a flat but tilted green on a direct line perpendicular to the fall line on an average 3 percent slope is not likely to break more than about 15 inches below the hole. So for almost all 10 foot putts, you probably shouldn't have an aim spot farther than 15 inches above the hole on the fall line. This is a very rough rule of thumb. For these putts, the aim spot probably needs to be within the leather above the hole. For a twenty foot putt, the aim spot probably ought to be somewhere in the vicinity of two feet above the hole. On faster greens, the aim spot is higher. On slower greens, the aim spot is lower. But not too much.
On any putt, the actual break the putt will accept depends on the speed. It helps to work backwards from the maximum break and the SLOWEST possible speed to the optimal speed you actually intend to use. The slowest possible speed is one that just gets to the hole, but it DOES get there and is not short. Any speed slower than this is outside the useable range. Imagine the break of this putt. Go hole-high for a slowest putt "read" of how far below the hole the ball stops on the fall line (the slowest speed will stop on the fall line and not cross it). This ought to give you the highest aim spot and the maximum break. Now don't play for MORE break than that.
Then gauge the LEAST break and the fastest putt. The fastest putt cannot be too fast so the ball jumps the hole. In general, even a centercut putt cannot be going faster than 8-9 revolutions per second, or it has ZERO chance of falling into the cup. Anything faster than this is TOO fast and outside the useable range. Imagine how far below the hole such a putt would cross the fall line from a side-on putt and then run across and past the fall line with its excess speed. These putts will probably run 4 to 6 feet past the fall line. Not much drop below the hole. This is the minimum break.
The optimum speed and break is usually about 3/4th the way up from minimum towards maximum. That is, a slowish putt with plenty of break is usually best for maximizing the chances of getting there, dropping into the cup, and not running too far by the hole if you miss. The aim spot ought to be about 3/4th the way between these two aim spots. In other words, stay within the useable range but err generously towards the high side.
That about all I can say right now.
Hope this helps.
Cheers!
Geoff Mangum
Greensboro North Carolina USA
"Your personal putting assistant."
The Putting Zone
http://hometown.aol.com/puttmagic
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Geoff, absolutely the best explanation I've ever seen.!
It has always bothered me when TV commentators talk about grain on a bentgrass green after being triple mowed at 1/8 inch, rolled, starved and sprayed with growth regulators. Maybe some TV commentators will read your explanation and LEARN something. Thank you for sharing.
Lining up my fourth putt. al
You're absolutely right! Here's a quotation for the USGA Mid-Atlantic Agronomist Stanley Zontek, in the USGA Green Section Record:
"Years ago, another title for this section could have been controlling grain. The fact is, the effect of grain on the roll of a ball is overstated today. When putting greens were cut at 1/4 inch, especially on bermudagrass greens, the effect of grain was real. With today's greens commonly maintained at 5/32nds of an inch or less, grain simply does not have a chance to develop. Today, when television announcers mention grain, the effect is more likely due to the slope and the contour of the green, not the way the grass plant grows."
If you want to read the full article about preparing greens for Tournament play, here's the url: http://www.usga.org/green/record/index.html. Search for "grain" in the Green Section Record.