The Science Behind Superb Wedges: Part II
July 23rd, 2012 | 
Author: 
So Many Choices...
In my quest to better understand pitching, chipping, and more specifically the low spinning wedge shot I needed to watch different professional players hit a variety of shots and be able to track the data from each shot. My objective was to understand how friction or grip between the face and the ball influenced the launch angle, height and spin rate. I have named the measurement of this grip and it’s influence on the golf ball – friction launch.
I need to explain some fairly detailed physics as to how I measure friction launch, so bear with me. The golf ball always launches somewhere between where the face is angled and where the clubhead is travelling – on both a vertical and horizontal plane. The ball also always launches closer to where the face is angled than where the clubhead is travelling. Where the ball launches between the face angle and the clubpath is primarily determined by club speed and friction between the face and ball. I needed to measure this friction in order to see how it effected the trajectory and spin on wedge shots.
With the help of Mark Reilly and Edoardo Molinari, we came up with the following formula to determine friction launch:
(Dynamic Loft – Launch Angle) x 100/Spin Loft = Friction Launch
This formula informs us where the ball launches between the face and path. The percentage indicates how far below the face angle the ball launched. A friction launch of 0% indicates that there was absolutely no grip at impact and the ball launched in the direction the face was angled at impact. A friction launch of 50% would indicate that the ball launched directly between the face angle and the clubpath and the grip was exceedingly high. By the way – neither of these are possible under normal conditions. The smaller the percentage, the higher the launch and lower the spin and vice versa.
With all the various situations I tested I needed to keep certain factors constant in order to be able to detect why the trajectory and spin rate of each shot was altered. My constants were TrackMan – to record the data; the golf club – a Titleist Vokey SM4 54 degree wedge; and the distance of each shot studied – 50 yards. If any ball landed short of 40 yards or longer than 60 yards it’s data was thrown out. The factors I controlled were the quality of the lie and playing surface, the grass and dirt in the grooves and on the face and the type of golf ball.
The Test Subject
Here are the average results attained from three professional golfers hitting 10 shots each in 7 different situations:
1. Clubface packed with dirt and grass/ProV1/off lie board (to eliminate additional matter)
- Friction Launch 17.9 degrees/Spin Rate 4408/Launch Angle 34.9 degrees/Height 31.9ft/Carry 51.6yds
2. Clean clubface/ProV1/off lie board (to eliminate additional matter)
- Friction Launch 28.1 degrees/Spin Rate 6501/Launch Angle 28.4 degrees/Height 25.1ft/Carry 50.3yds
3. Wet clubface/ProV1/off lie board (to eliminate additional matter)
- Friction Launch 28.1 degrees/Spin Rate 6564/Launch Angle 28.7 degrees/Height 25.7ft/Carry 50.4yds
4. Clean clubface/ProV1/off turf/preferred lie
- Friction Launch 31.9 degrees/Spin Rate 7178/Launch Angle 26.1 degrees/Height 22.3ft/Carry 48.9yds
5. Clean clubface/hard range ball/off turf/preferred lie
- Friction Launch 28.8 degrees/Spin Rate 6625/Launch Angle 27.6 degrees/Height 25.1ft/Carry 50.8yds
6. Clean clubface/ProV1/off a new mat
- Friction Launch 30.4 degrees/Spin Rate 6859/Launch Angle 26.8 degrees/Height 23.3ft/Carry 49.2yds
7. Clean clubface/ProV1/Off a tee
- Friction Launch 30.6 degrees/Spin Rate 7259/Launch Angle 27.6 degrees/Height 24.8ft/Carry 51.2yds
Edoardo Molinari was also kind enough to submit his TrackMan data to me from the 10 shots he hit with his 60 degree wedge and 10 more with his 56 degree wedge: (the following shots were hit with premium golfballs, off preferred lies and cleaning the clubface between each shot)
60 Degree Wedge
- Friction Launch 22.9 degrees/Spin Rate 6048/Launch Angle 36.2 degrees/Height 34.8ft/Carry 51.0yds
56 Degree Wedge
- Friction Launch 24.4 degrees/Spin Rate 6046/Launch Angle 34.2 degrees/Height 31.5ft/Carry 50.5yds
NOTE: After a few weeks of practice Edoardo has improved his 10 shot average with his 60 degree to a spin rate of 8700rpm and a Launch angle of 26.1 degrees! There is something to this…
The deductions I took from the above tests are as follows:
- Shots out of the rough, first cut or even into the grain lies are always going to launch higher, spin less and as a result fall out the sky faster and roll more after landing – no matter how good you or your wedge is. There simply is too much ‘matter’ involved between face and ball to create optimal friction.
- A wet clubface actually makes very little difference in determining how much friction, and thus spin, is imparted on the ball.
- A premium golfball makes a noticeable difference with the wedges. Not only will it add distance off the tee, but it will also allow you to hit better and more predictable short shots.
- If the rules allow you to tee the ball up – go ahead and do so. You increase your ability to place the clubface cleanly on the back of the golf ball.
- Hitting pitch shots off mats is a fantasy world and can only increase the ‘illusion of competence’. No bad lies, nothing between the face and the ball, minimal consequence to heavy shots...
- For pitch shots, higher lofted clubs do not spin the ball significantly more than the next wedge down (60*vs56*). They do, however, get the ball to stop slightly faster due to a steeper landing angle.
- Average friction launch for a 50 yard shot is around 25%. The lowest friction launch was out of the poorest lie (18%) and the best results came from an ideal fairway lie, a new and clean wedge along with a premium golfball (32%).
- The quality of the lie is the most important factor in allowing a golfer to control the trajectory and spin of the wedge shot they are about to play.
Let’s take a look at the factors that influence friction launch:
The Golf Club
- The sharpness of the top edge of the groove will effect spin, yet most of the spin on a shot comes from the roughness of the area between the grooves.
- In my opinion the wedges that provide the highest amount of spin are the models that have the roughest surface between the grooves – the new TaylorMade ATV and the Nike Vr Pro wedges seem to do an excellent job with ‘between groove’ treatment.
- An excellent way to improve spin with your current wedges is to have the face sandblasted with normal aluminum oxide sand. This will provide a rougher, more ‘grippy’ texture to the face.
- The number of groove edges that come into contact with the ball also effects backspin. In pushing the limit of the groove rules manufacturers can now put five grooves on the surface of the ball at impact versus the traditional three.
- Grooves channel away some of the moisture and matter from rough that gets between the ball and face – but seldom all of it.
- The grooves and face of your wedges should always be very clean – even when you’re practicing. Keep a towel or brush handy to clean the club after every few shots.
- If you are serious about competitive golf I would recommend having a tournament set of wedges and a set you use in practice. Every shot you hit wears down the face which reduces friction at impact.
- In fact Gary Player would ensure that his caddie never cleaned his wedge after hitting a sand shot – the sand particles on the face helped to create more friction between the face and ball for his next shot.
Turf Type and the Quality of the Lie:
- When you are into the grain you will often get grass caught between the ball and the face, thus reducing grip. A down grain shot will ‘cut’ very little grass and thus allow for clean contact and increased grip.
- Different turf types are thicker and stronger and thus, even at fairway height, support the ball enough to keep it up and away from the grass. This makes it easier to have a higher friction launch factor. If you’ve ever played off kikuyu grass you’ll know what I mean.
- When laying up on a par five understand the value of high friction launch – lay up in the fairway and don’t be greedy.
The Swing
- This is where I am now focusing my efforts. There does seem to be a method that DOES NOT involve a more open face, increased speed, higher launch or a cutting action that seems to produce a lower trajectory with a much higher spin rate. Stay tuned…..
Read part one of this article HERE
Posted in Equipment, Practice, Short Game, Swing Philosophy | 
Tags: aluminum oxide sand, amazing wedges, best wedges, bite with wedge, carry distance, chipping, control the trajectory, edoardo molinari, ernie els pitching, friction, friction launch, great wedge play, heavy shots, height, high friction, illusion of competence, landing angle, launch angle, low checking wedge, low spinner, low spinning wedge, mark reilly, pitching, short game, spin rate, spinning chip shot, wedge with bite, wet clubface
A very informative article. The information regarding the gaps between the grooves rather than the grooves themselves was an eye-opener. Thanks for all your hard work Andrew.
Really great research here. I’d be interested hot CC grooves compare to the likes of the Callaway X-Forged / Jaws with the old Mack Daddy Grooves but great research.
The area on sand blasting the clubface would contradict golf rules surely?
And Two sets of wedges is a must!
Great blog post and some great TrackMan data. I think you guys who research and share the information are brilliant and I assure you we all appreciate it. I cant wait to see the verdict on the swing theory.
During his warmup prior to the first round of the PGA Championship last year in Atlanta, we watched Darren Clarke hit shots on the short game practice area at Atlanta Athletic Club. Clarke’s shots were DRAMATICALLY lower and “spinnier” than any other player’s, from the fairway and from the sand. It was truly amazing to see a world-class player do something that was so different, and at least in this context so much “better” than the other world-class players…
Andrew. Thanks for the great research. I am however a little confused and was wondering if you could please provide some clarification. Could you please explain why spin loft does not “work” for this shot? Also, I think that friction is directly proportional to the applied load. So, what is the club head speed of these players? Is it higher then a typical amateur or does this variable matter? How about centerness of contact? THANK YOU!
Hi Brendan,
Thanks for reading and I appreciate your questions. Nowhere do I state that spin loft does not work – it is merely physics and simply is what it is. I do, however, say that when it comes to pitching it is not the primary factor that determines loft/launch and spin. Normally the broader/greater the spin loft the greater the spin and loft. For these shots that is not necessarily the case. The higher the friction launch due to grip on the ball (no matter what the spin loft is) the higher the spin and lower the loft/launch….make sense? The ball can launch low and spin high even with a spin loft that indicates it should launch higher with fairly high spin.
Clubhead speed was somewhere between 51 and 54 mph for all situations tested – thus my reason for keeping the shot to 50 yards – to keep the reigns on swinging faster and increasing the ‘applied load’. I have seen numerous examples of lower clubhead speed and much higher spin, but I will be reporting on that in the next few weeks. Not sure how the speed relates to the average amateur. Because the numbers I shared were averages from multiple shots I’m assuming the players also averaged a centered strike.
Anything else just shout…
AR
Andrew – This is very well done research. Starting using 2 sets of wedges this year and using the pro v1 ball. Consistency around the greens has improved greatly!
Looking forward to your next article in the series.
Cheers Jim – glad to hear its helping.
Andrew,
Great article and research! This has given me some answers to what I have observed and suspected for years but could not even begin to explain. Some of my suspicions uncovered include:
1. Pitching with range balls off of “common driving range” lies versus a ProV1 off of firm, tight “country club” lies produces a night and day difference. The latter produces a level “boring” flight that seems to “float”. Range balls launch high and the ability to control trajectory is greatly reduced. Now I have a better understanding of why!
2. More loft doesn’t necessarily translate to more spin. This one has had me stumped for a while. I carry 2 Titleist wedges. A 54* with 14* bounce and a 60* with 10* bounce. I have the non-conforming grooves on both wedges. (The rules say I can still play them so why not?)
I have observed that when I hit 10-60ish yard pitches with my 54* the ball comes off of the face very hot and low with lots of spin versus the 60*. So much in fact that when struck from a clean lie the cover of the ball gets excessive groove damage. (sometimes I even lay up to a different yardage just to save a brand new ProV1):)
3. It seems to me that when I swiched to a much higher bounce on my wedges, particularly the 54* with a whopping 14* bounce, my trajectory came down and my spin went up. I have also come to learn through experimentation, that when I reduce the amount of wrist cock which, in turn, creates a longer shallow flat spot at the bottom of the swing, the result is the ultra low “super spinner”.
Now I have a question…. Does the amount of bounce taken advantage of on the club influence launch angle and spin rate? Seems to me that more bounce equals less turf interaction producing the “nipped” shot. My suspicion is that it does, but again, I have absolutely no way of explaining why other than saying “It just does” which doesn’t usually hold up in court….
By the way, one of the best pitching tips that I have ever heard came from you to me a few years back. You told me to “Feel like the clubhead gets back to the ball at impact before the handle does.” This thought has personally done wonders for my chipping and pitching and I have passed the advice on to many of my students who seem to do a lot of “Gardening” with the leading edge of their wedges.
Thanks Andrew,
Brian
Thanks Brian! Here’s a good way to think of the bounce – it does not add or reduce turf interaction, but it certainly reduces leading edge and thus face interaction with the turf, which would lead to a cleaner strike and thus greater friction and spin.
I hope you are well mate!
Great stuff, I always appreciate the empirical efforts of the golf “truth finders”.
I especially liked these gems:
“A wet clubface actually makes very little difference in determining how much friction, and thus spin, is imparted on the ball.”
“In fact Gary Player would ensure that his caddie never cleaned his wedge after hitting a sand shot – the sand particles on the face helped to create more friction between the face and ball for his next shot.”
Hello Andrew,
having a very dynamic golf swing and compressing the golf ball, I have a hard time shallowing out the angle of attack for the half pitch shots. Is there any certain drills you can recommend that keep the shaftlean up , yet promotes more bounce at impact?
I really like you website.
Thanks
CT
Thanks for reading CT! I am currently working on an article that will address exactly your question stay tuned. You need to feel the handle working up and towards you to stop hitting down so much…
Thanks for your efforts in explaining these matters; I’ve thoroughly enjoyed your writings, and I have a few questions on your research.
You suggest that the low spinning wedge shot is better than a higher, less-spinning shot. At what percent friction launch do you feel that there are diminishing returns (i.e., what is the happy medium)? A very low, super spinny shot has disadvantages, such as greater variability based on the friction of the landing surface and greater influence of elevation change, thus increasing guesswork.
Do you feel that the technique to create low launch/high spin wedge shots is more exacting and therefore prone to bigger misses? Would you encourage all golfers to play these shots, just single digit handicaps, or pros only?
In what scenarios does Mr. Molinari like to play his 8700 RPM shot versus more traditional shots?
Have you researched ground conditions for where the ball lands yet? If you’re shooting at a hole where you have to stop it really fast, will low launch/high spin always stop sooner than higher launch/lower spin? I could envision a low launch/high spin shot acting more erratically on a firm green covered with dew, for example, or a recently aerified green.
Have you taken this research to hitting out of bunkers?
What methods were used to determine that the friction of area between the grooves, not the actual grooves, is the greatest factor determining spin rate? That seems like a hard test to conduct without other variables getting in the way.
What coarseness of sandblasting will the USGA permit?
Thank you for taking the time to read my questions. Keep up the great research and writing!
Andrew,
Really enjoyed reading your arcticle and watching your videos – great stuff! Being s scratch golfer myself only now, after years of practice, am I slowly starting to get a knack for the low spinning pitch shot. I just wish I’d come across your article a little earlier! Anyway, the way I hit the shot is I do exactly as suggested in your videos but for me the key on increasing the friction lauch (and this is by no means based on any scientific evidence whatsoever) is the following:
I make sure not to open up the clubface in the backswing and, more importantly, I make sure I keep the face from turning over after impact at all costs. It almost feels as if the club releases ‘upwards’ instead of ‘around’. I like to think of it in tennis terms as not trying to hit a (high launching) forehand top-spin by ‘releasing’ the racket (i.e. clubface) but rather a low spinning slice shot (only without the slice).
I practice the shot by setting up to the ball squarely, then closing the clubface a good 10 degrees or so before hitting the shot. In order to still hit the shot at the target you have to really feel as if hold the face open as long as possible. That way I can feel the ‘release’ I want and it also ensures I’m not hitting down on the ball too much.
Again, I’m not pretending to know anything about this shot at all. It’s just a feeling that works for me when trying to hit the occasional low beauty. Really looking forward to what your research has shown on the proper technique!
Best
Sounds good Max! Have been doing a ton of work on pitching this past year and I am currently working on a video that explains the technique in full. Thanks for reading and keep up the solid work.
Sincerely,
Andrew
Andrew this is great work. I had heard through the grapevine that you had been using high speed cameras and Trackman to see the spin coming off with the wedges. Great work! If you’re ever in the Northwest please stop by so that I can grab you a drink for this research!
Thanks very much Travis!
Hi Andrew
thanks very much for all the detail in the above article, i have been trawling the internet for as much detail as i can for my PGA Assignment on hitting pitch shots.
your work will be referenced in my work and im really hoping for top marks with thanks to your hard work.
i am currently in my first year as an assistant professional in the south east region of the UK
many thanks again
Matt
Happy to help Matt! All the best in your assignment.
Do you have any hard data to support the surface roughness between grooves increasing spin? I’m not sold on “extra grooves between grooves” producing more spin, it seems to me like decreasing surface area would also decrease the pressure applied to the ball. Good luck on your research!
Hi Ryan,
Just like I have done the research and testing, I would encourage you to do the same so that you can form your own ideas and beliefs. This site is purely me sharing my beliefs, opinions and findings.
Thanks for reading.
AR
Hi Andrew, thanks for some very interesting articles. I am currently working with my Pro to eliminate the divot from my wedge shots and to “bruise” the grass instead – and I’m not finding it easy, so looking forward to your next article (when might that be out ?)
Recently, however, in order to beat the wind, I have been using my “55 yard swing” (which goes 55 yards with a 52 degree wedge and I think of as forming an equal ‘V’ shape between my left forearm and the club shaft on the backswing and on the follow through) but using a pitching wedge, 9, 8 & 7 irons and I have been astonished by the amount of check these shots get, where I have not been hitting them very hard at all. An 8-iron will go about 95 yards (obviously fairly low) and will stop inside a yard, which amazed me when I first saw it. But it’s quite a gentle swing, and I feel there is very little wrist break going on and, presumably like you say, a fairly shallow angle of attack.