How-To "Backspin on chips"

So much ado about nothing.....really, we're not talking about launching a rocket ship here. Sure, physics is involved in spinning a golf ball, but does one actually need a detailed and definitive analysis on the subject in order to execute the shot. Most good swings produce the necessary backspin to stop the ball on approach shots. Ask a pro how he does it and you'll get a very simplistic answer. Many years ago, I played golf regularly with an ex college golf team player who could do some amazing things with a gold ball. The feat that impressed me the most was not his 300+ yard drives, but the way he could bring a ball into the green from 20 to 30 yards out and stop it on a dime. The ball would come in hot, a foot or so high, take a short bounce or two and stop cold. The first time that I saw him do it, my thoughts were that the ball was surely going over the green , down the hill, and into a creek below, and I was going to win the hole. It never happened. When asked how he did it, he simply responded, "I just hit down on the ball".

Some of us like to discuss these things and they may matter to us. If you find it an "ado about nothing" of course you are entitled to then you can just leave it. It's not compulsory.

Ok, why don't you model the problem. Write it in C++ visual using either a .Net or MFC framework and make it flexible. Set up a 3-axis ball frame and a coincidental inertial rest frame. Initially, with the ball at rest on a semi ridgid surface, the direction cos matrix between the two frames would , of course, be identity. Certain independent variables such as angle of attack, drag coefficients, mass properties and ball elastic characteristics, and club mass and acceleration would be needed for moment and force computations - probably 3 or 4 variable function table lookups. You could then determine spin rates in each axis, compute your quaternions, update your matrix, extract the euler angles (spin displacements) , integrate the translational accelerations and get your ball position. Update your state parameters every millisecond and allow for selectable input conditions. You'd need only be concerned with club-ball collisions in quadrant 2 of the x,y plane plane in both z directions. Surely, a guy such as you could handle this task.

I started by posting a technical reply to your post but decided to delete it and ignore you. In retrospect I am too old for such trivialities, your comments do not impress me. I have been an Engineer a CadCam software programmer and Managing Director of a CadCam development company before retirement, I don't need to qualify myself.

Rookie. Fire up the Turing engine and code that spaghetti style.

I hate to beat a dead horse but I wanted to say that MOX is wrong.

I have read the posts because I too am interested in techniques for developing a low spinner. I am not a golf pro by any means, however, as an engineer and as someone who has taken physics 101, 201, 301, and 401, I can say that the force applied to the golf ball is perpendicular to the angle of the clubhead. The ground does not influence the launch angle at all. If it did, a fairway bunker shot would just plug everytime. Further, the direction of vector does not really apply to the launch angle, however, it does impact the friction factor of the club on the ball (spin) and it has an impact on the force applied to the ball.

If I open up the club head by 30 degrees yet swing straight back and straight through, the ball will initially start 30 degrees right. It does not travel straight, therefore the direction of the vector is irrelevant. The same principle applies to the launch angle.

Trapping the ball is a misnomer and is impossible to accomplish with a golf club. Trapping the golf ball is more of a helpful swing thought.

If you do not believe me, please read page 86 of The Scientific Truth of the Golf Swing by Steen Winther. It is right there in black and white. Trapping is impossible. Time to take a physics 101 refresher course dude.

M

__________________
Matt

Whoa there BrianW......you are defensive. Your credentials aren't being challenged. We all have backgrounds - I'm a house roofer myself, but I don't feel threatened if someone might doubt it. My post was more intended as facetious than factual. I was sugggesting a template approach to simulate the event with some of the necessary processes. I'll let better heads than mine fill in the necessary modelling particulars.
Regardless, such a model can become a very compute intensive problem. Ball spin rates would likely require a state integration step size of more like a microsecond than the millesecond rate that I previously mentioned - and, some nth order Runge kutta integration scheme for accuracy. Euler angles would be needed for the visuals - displaying ball geometry along the timeline. This task is probably best left to the R&D people at places like Nike and Titleist. But as was previously stated, this is just a lot of ado about nothing when it becomes time to make it all happen on the golf course. So, enough golf diversion.....I got a house to roof. I'm outta here !

I once created a 100% accurate model of a honey bee.
Whenever I ran the model the bee was unable to fly.
Hows that for learning nothing from a model.

Hi
just as well it was not a bumble bee? that is even harder to understand how it can fly.
cheers
bill

As I politely suggested previously, you have the right to ignore a subject if it's not for you.

Another video which shows that Bill and Brian are correct.

Hitting below the equator of the ball with a loft of less than 90 degrees can only send the ball upwards with backspin.

the way i play it, and i'll admit i need more practise as it doesn't always work for me...

very similar to that video, but on a lesser scale.. if i want a higher trajectory i take a bigger backswing..

however if i want that short jab, skip and stop, i play my feet closer together than putting which is normally shoulder wide. ball in middle of stance, take my SW (56degrees), stand over the ball and teh secret is to take a small or very short backswing, maybe only 12 - 15 inches back, the stroke is like a putting stroke with confidence, keep your hands ahead of the club and firm, follow through and try to stop as soon as you've hit the ball.. usually ends 12 - 15inches after the ball.

idealy the club you use should have a milled face so you get that extra bite.

i don't like using my LW for chipping, i hit too many fat. the SW is easier i find as it has a little more bounce and doesn't dig into the ground.

Simple tip: Hit down on the back of the ball, with right hand cupped, face slightly open and ball a little back in your stance. This should encourage maximum loft from your club face which in turn will compress the ball and give the spin you want