Leading Side Leverage & The Trebuchet

trebuchetOriginally published July 25, 2013

Many of my readers will remember my postings in earlier days on the “trebuchet” effect found in the golf swing.

Now, the “trebuchet” concept I brought up from time to time didn’t really work for some people in the sense that it was more a vague notion explaining the “drop” of the head to the rear and back during the down swing.

It seems there would be another way to explain leading side leverage however – the trebuchet!

I was looking for something to better explain the leading side leverage and it took me back to my old standby, the trebechet.

It is even written in some scientifically-themed sites and blogs that the golf trebuchet principle is found in the golf swing itself, so I’m not the only person to have thought of this.

See, if you turn the trebuchet upside down, you would have the catapult arm now being the left or leading arm at the bottom of the swing.  If you lifted the drop-weight, the arm would fall, correct?

How about this explanation from this Real World Physics Problems site (I’ve inserted the bolded text myself separately):

As you can see, the counterweight pivots around a much shorter distance than the payload end. The advantage of this is that the payload end of the beam (the hands at the end of the leading arm) reaches a much higher linear velocity than the counterweight end of the beam (the left or leading shoulder).

This is the principal of mechanical advantage, and is what allows the payload to reach a high launch velocity.

However, because the counterweight pivots around a much shorter distance, its weight must be much greater than the weight of the payload (the club head), to get a high launch velocity. However, increasing the mass of the counterweight beyond a certain point will not help, since the limiting speed of the falling counterweight is free-fall speed. (gravity drop!!!)

So, if you look at the C7 as the fulcrum in the trebuchet, then you would see that movement of weight at the end of the catapult arm would move the arm itself.


So, if you think of using your weight to produce leading side leverage to your swing, you have to forget about the harpoon and other things that have to do with people thinking “down” with the hands and club.

Rather, if you are at the top of the back swing in the cranked position, you have to think of how the shifting of your weight back to the leading foot will cause your coiled position at the top to reverse.

Where you had your right shoulder back behind you and your left shoulder down and beneath your chin, the shifting weight (with a stable C7 as the fulcrum) will produce the trebuchet effect – as your weight moves and settles on the leading foot, your hips must open with the swivel action, and this pulls your left shoulder forward, then up and away from its “at the top” position.

This is unstoppable.  This is leverage.  Your body mass moves to the other side of the fulcrum, moving your leading shoulder back and away, leveraging the left or leading arm downwards. Combine that with the gravity drop that occurs anyways, and you’ve got your leveraged down swing.

This is where my “Leading Foot Stomp” also came from – I knew that the more aggressively I shifted my weight to that leading foot (when you do it really fast, it looks almost like a stomping action with the leading foot to really load that gravity drop & acceleration into impact).


8 thoughts on “Leading Side Leverage & The Trebuchet

  1. Buddhabob

    good to read this again. The caveat might be that a golfer should probably remember that after the ‘drop’ he should short stop slide into the finish or at least not fall back on the rear foot as Winther does with his Mickey Mantle swing.

    The slide itself is fairly natural but it also is a move that is opposite the upper trebuchet which happens thru impact with the upper body moving back. It can actually feel quite natural to leverage a big angled lead leg and fall back on the rear leg but I don’t think thats healthy and I’m not sure if you get more distance doing it ala Winther. Don’t know if this makes much sense. Back to Zen practice, later.

    1. D Watts Post author

      Good point, Buddhabob!

      The slide will happen naturally, as you say, if you transfer the weight fully to the left foot and leg and don’t try to anchor yourself with the right toe. Smooth sailing, all the way.

      I just got back from the golf course and have to run for a business meeting, but I was loving my ball-striking today. So nice to be back out after that brutal winter 🙂

  2. Buddhabob

    So I have a big question for the DJ that’s spinning records here. I have seen your vid on the flipping of the left hand thru impact. I have watched the Dunaway vid where he explains that its the secret to added power. But whenever I tried it before I got smother-hooks since the clubface will close quite a bit with this kind of action.

    Today I just practiced the address with an OPEN clubface and then practiced the left wrist roll at impact. After 5 or so balls I was beginning to make good contact. Immediately I get full extension of both arms thru and after impact with the under side of the left arm rolling open and skywards effortlessly.

    My question is how does the DJ or anyone else do this without hooking badly if the address is with a square club face? Up until now I have been doing the SadLow impact, hitting the ball with the small side of the left hand and then on thru without flipping the left hand. That action though tends to shorten my left side for whatever reason.

    Any ideas?

    1. D Watts Post author

      Buddhabob – neutral grip, for one, and having the correct set-up at address, and getting that angle right on the down swing.

      Offhand, that’s how I’d say you do it.

      PS – Keep in mind that it’s not an isolated action, it’s in conjunction with the right hand and if you’re thinking about it, you’re probably doing it early, leading to the hook.

      Practice it consciously swinging one-handed, but swing unconsciously.

  3. Buddhabob

    not sure thats going to do it. I wonder if it can be done with a strong grip. Anyway the confusion is probably because I am Irish-Jewish.

    1. D Watts Post author

      Strong grip? Can’t help you with that one, my friend, I only swing and deal in neutral, but that answers why you can’t swing with that action at least, and it’s not just you… 🙂

      PS – And with that, the wings are done and dinner awaits, good night all!


  4. Buddhabob

    Interesting what has not been discussed and its quite simple. How far are you standing away from the ball? Many people ‘crowd the plate’. Gives them more of a feeling of control. This logically leads to a vertical swing plane. When you really extend your arms out at address the swing suddenly flattens out, this is clearly true when your holding a 48″ long driver. More grist for the mill.

    I think I have yet to account for the longer club and can definitely stand further away. This automatically guarantees more inside out action on the downswing just to be able to reach the ball at impact. My opinions only.

    Dominic Mazza who some have said had the best swing in longdrive is a classic example of all of this. He stands hugely away from the ball to maximize the circumference of the long club he is using and allow for effortless motion and inside out attack.

    1. D Watts Post author

      Even the best PGA Tour swingers, forget long drive, have always had a forward angle to the arms at address – Nicklaus, Snead, Hogan… look at their address positions dtl and you’ll see it. The swing plane is diagonal, not vertical or horizontal – makes sense to me!

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