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New Millennium Golf Science
where golf myths get debunked
"It's not what you don't know that hurts you, it's what you know that just ain't so." -- Mark Twain


Picture this: a pro hits a wedge from a hundred yards out and it lands past the flagstick. Instead of rolling off the green (like our's do) the ball rolls backwards and into the cup. The crowd goes wild! We've all seen it happen. How did he do that? The answer is simple…

…BACKSPIN…

Every golfer wants more backspin and everyday thousands go "in search of" how to get it. They are not disapointed. A google of: backspin + golf yields literally thousands of how-to (put spin on the ball) explanations. The problem is, almost all of them are wrong. Contrary to what the experts would have us believe…

  • Backspin is not a result of hitting down on the ball
  • Backspin is not caused by trapping the ball between clubface and turf
  • Backspin is not because of grooves on the clubface latch onto the ball
  • No way! you say… The local pro said so… Your instructor told you so… The guy that sold you your golf clubs said so… Your know-it-all golf buddy even said so… Well guess what… they're all wrong!

    why a golf ball spins backwards and
    how to get more spin
    are the stuff of modern golf myths

    What DOES cause backspin? That my fellow golfer is what I'm about to explain. Make yourself comfortable because the answer cannot be had quick and dirty. We must first establish the core concepts then use them to solve the problem. I guarantee this little journey will be worth it. Perhaps for the first time you'll finally…

    KNOW TRUTH ABOUT BACKSPIN

    Before we explain WHY, which is the job of physics, we must agree on WHAT. We're not talking about some circus perfomer's trick shot. We're not considering any use of the club in a manner for which it is not designed. We're talking about ordinary golfers with ordinary clubs making ordinary contact with ordinary golf balls. Agreed? Good then lets start at the beginning.

    Core Concepts

    Newton's Laws


    Issac Newton
    (1642-1727)

    First there was Aristotle (who got it wrong); then later came Galileo (who got it right) but it wasn't until Sir Issac Newton appeared on the scene that things really began to clear up.

    In 1687 Newton published his Principia Mathematica in which he summarized his famous 3 laws of motion

    FIRST LAW

  • An OBJECT STAYS AT REST OR IN MOTION UNTIL IT IS ACTED APON BY A FORCE

    SECOND LAW

  • THE ACCELERATION OF AN OBJECT IS PROPORTONAL TO THE FORCE ACTING ON IT AND INVERSELY PROPORTION TO ITS MASS

    THIRD LAW

  • WHEN AN OBJECT EXERTS A FORCE ON A SECOND OBJECT THE SECOND EXERTS AND EQUAL AND OPPOSITE FORCE
  • These three laws form the basis of our understanding of why things do what they do. Laws apply in every reference frame. In order to be valid an explanation must comply with Newton's three laws of motion and if it does not, then it should immediately be tossed into the waste bin of myths and ledgends.

    Scalars vs. Vectors

    A scalar is a number… a value… a quantity which can be added, subtracted multipied and divided. A vector is a number that also has a direction. Vectors point somewhere. Vectors a tell us more than scalars and like scalars, vectors can be added and subtracted. The "component" or portion of a vector that is associated with a specific axis or direction can be found by multiply the value of the vector by cosine of the angle the vector makes with that axis.

    Velocity

    Velocity is the average distance covered in a given time. Its how fast something is moving. Its what the speedometer in your call is telling you. Duh... Simple right? I meant it when I said we were going to start at the beginning.

    Acceleration

    Accleration is a change is velocity. Its what happens when we step on the gas pedal to speed up. Its what happens when we hit the brakes to slow down. Its what happens when we go around a corner at a constant velocity… Did I here you say: WHAT? Let me say it another way: when we go around a corner or curve we are being accelerated. I bet that: "threw you for a loop" :) didn't it…. We don't often hear the words: "acceleration" and "contant velocity" used in the same sentance.

    This and important concept and we need to make sure we understand it. Newton's first law tells us that the only way an object can speed up, slow down or CHANGE DIRECTIONS is if an acceleration acts on it. Newton's second law tells us that a force is proportional to mass times acceleration. In order for anything to move in a circle it must be accelerating "centripetally".

    We just introduced a new word into the lexicon so lets define it. "Centripetal" means: directed towards the center.

    Curvilinear Motion

    WHAT CAUSES BACKSPIN?

    Backspin happens when the golfball is struck below the center of gravity. (Even a driver with an accending path at impact creates backspin). Because the point of impact is not inline with the center of gravity of the ball (but below it) and because the ball has inertia, a moment is created at impact. (A moment is a force times a distance... think of a lever arm... you apply a force, at a distance creating a 'moment' at the fulcrum).

    How to put Spin on the Ball

    Getting a golf ball to stop quickly or even spin backward can be a real lifesaver when you're hitting onto firm greens or when the pin is placed directly behind a bunker or water hazard. Read more...

    How to put spin on a golf ball - Be sure to trap the ball with the clubface and hit the ball first.

    More backspin - Set up with your feet a little closer together. Put the ball farther back in your stance. If you have problems hitting the ball clean and are always getting it thick, set up as if the ball is 2 inches ahead of where it actually is. It worked for me.

    Spin - Get a lob wedge and place it at the back of your stance and hit down on the ball.

    Spin - Don't buy a Canadian tire wedge. Buy a Wilson Harmonized and scratch the face with an X-Acto-knife to roughen the face. Then use a ProV1 and hit the ball hard.

    Backspin - Having a golf ball land and then spin backward 10 feet or so is something that many people just don't have the ability to do. If you normally play high compression balls, forget about it. They just will not spin enough, unless you swing faster than John Daly.

    The best that you can do is limited to your current club head speed. Yes, you can place the ball slightly further back than normal to get a little more backspin. But, anything more than a ball width or so de-lofts the club too much, negating any extra backspin because of the resulting lower trajectory produced (that is called a punch shot ).

    I tell my students to go by their driver speed. If you have less than 100 mph go with an 80 compression ball and play the ball back about an inch or so and live with what you get. Be aware that you will also get a lot more side spin than you are used to on misshits.

    If you generate 100-110, go with a 90 ball and expect to see the ball one hop and stop for everything up to about a 4 iron. None of that stuff they see on TV though.

    If you are one of the lucky ones who generate up to about 120 mph, go with a 100 ball and expect the same. The higher swing speed people, 100-120, can expect a one hop back (maybe a foot or two) when hitting a fade with the compressions I recommend.

    If you really want to use a softer ball to get more than that (possible), be prepared to lose distance and suffer more penalty from misshits in general. The truth is never what people want to hear. If your two iron doesn't go as high as your wedge than you would be much better served by learning how far your balls actually release on the green.

    Back spin on the ball - Take out your lob wedge or sand wedge (depending on the distance to the green) and have the ball back in your stance. I find it helpful to choke up slightly on the club. Hit the ball shallow, ensuring you hit the ball first and then swipe the grass throughly under the ball. Watch it softly creep back on the green, it's art work really, and quite simple if you don't try and make it difficult. ;)

    Stop the ball bobbling on a putt - When you take your stance to putt, just as you're going to take your backswing, push your hands forward in line with your left pec muscle.

    Backspin - To put backspin on your shot, take out a 56 or 60 degree club. Position your feet closer than you regularly would. Place the ball directly in front of your back foot. Make a downward swing, making contact with the back of the ball first and then the ground, making a divot. The ball should hop once and then stop. Works for me.

    Spin - Put the ball on your index finger and apply side spin. You have spun the ball!

    Zest on your ball - To spin the ball back, you don't need to take a lob wedge only, a sand wedge can also be used and will go a little farther (which means higher, which means more spin).

    Backspin - Having a golf ball land and then spin backward 10 feet or so is something that many people just don't have the ability to do.

    If you normally play high compression balls, forget about it. They just will not spin enough, unless you swing faster that John Daly.

    The best that you can do is limited to your current club head speed. Yes, you can place the ball slightly further back than normal to get a little more backspin. But anything more than a ball width or so delofts the club too much negating any extra backspin because of the resulting lower trajectory produced (that is called a punch shot).

    I tell my students to go by their driver speed. If you have less than 100 mph go with an 80 compression ball and play the ball back about an inch or so and live with what you get. Be aware that you will also get a lot more side spin than you are used to on miss-hits.

    If you generate 100-110 mph go with a 90 ball and expect to see the ball one hop and stop for everything up to about a 4 iron. None of that stuff they see on TV though.

    If you are one of the lucky ones who generate up to about 120 mph, go with a 100 ball and expect the same.

    The higher swing speed people, 100-120 mph can expect a one hop back (maybe a foot or two) when hitting a fade with the compressions I recommend. If you really want to use a softer ball to get more than that (possible), be prepared to lose distance and suffer more penalty from miss-hits in general.

    The truth is never what people want to hear. If your two iron doesn't go as high as your wedge than you would be much better served by learning how far your balls actually release on the green.

    Spinning the ball on full shots - Spinning the ball on full shots is really all a matter of contact and clubhead speed. If you can contact the ball cleanly (no earth or grass before the ball), then you are going to add some kind of spin. By hitting slightly down you add backspin. If you have ever hit a shot that went into the air, then you have put spin on your ball. The problem is that most people want to add more spin. To get that work on hitting you wedges as high and as solidly as you can.

    Remember that the pros are hitting soft (expensive), balls into fast and severely sloped greens, so they get a lot of action. They also hit the ball very cleanly with a lot more clubhead speed than you do. If you can hit the ball 250 yards or so with your driver though, you should see some spin in every short iron shot that you hit. The higher that you hit the more that you should see.

    Weaker shafts help to promote spin and a higher ball flight, so that is an option for anyone that lacks height to their shots. The bottom line is you have to hit the ball super high to get the kind of action that you are looking for, yes there are time that the pros hit low spinners, but that is another technique altogether, and if you are having trouble getting a normal amount of spin forget that shot. Hit it high, clean and with high clubhead speed and you will see spin hitdowndammit!

    As a result, the ball becomes trapped between the descending clubface and the ground. The ball compresses.
    The Spinning Edge  

    From Issac Newton: Sum of moments = moment of inertia of the golfball times the angular acceleration. Spin is angular velocity. Acceleration is rate of change of velocity.

    So.... How do you increase the backspin? There is only one way to increase backspin... increase the moment at the time of impact. How do you increase the moment? Either one of two ways: by striking the ball farther away from the center of gravity (this is what clubface loft accomplishes for us) or by increasing the force at impact. How do you increase the force? By increasing clubhead velocity or by using a heavier clubhead. Force is proportional to clubhead velocity and mass.

    Ever notice how some wedges are really heavy? This helps generate more backspin because more force is imparted for a given clubhead speed. Ever notice how a pro will sometimes open the face up even with a high lofted wedge? This helps get the impact point even farther under the CG of the ball... even farther away from the center of gravity which increases the moment hence backspin.

    The only thing hacking down on the ball accomplishes is to make a great big divot. You cannot strike the ball with a steep enough decending blow angle to make much of a difference that way. That's a nice sounding totally bogus theory.


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