So, obviously, my most recent distance breakthrough came from activating my left side. As far as I can tell this comes in two main parts. First you use the left side to pull the upper body around with more tension during the backswing, and then, once the weight shifts, the chest and core create a springboard to rotate the right side through faster.
Loading the Backswing
This part clicked for me while watching a Simon Lizotte clinic.
Right at the 10:20 mark he says that in a full reach back you should really be using your left shoulder to pull your body around. This loading of the backswing with the left shoulder is what makes the unloading of the tension so effective.
Unloading the Backswing
I can't begin to guess how much I've watched Paul McBeth slow motion videos, but it's a lot. One thing that he does very obviously is pull his left arm in with his chest and core right as the weight is shifting to the front foot. Focus on the action of the left arm beginning at around 8 seconds.
He goes from having the left arm lagging behind to abruptly pulling it in to his midline creating tension that springs his right side open with a ton of added force. If you could see his chest and core right now I guarantee every muscle would be tense The timing of this action is extremely important, but once your left side goes from being weight that is slowing down your rotation to tension that speeds it up the difference is amazing. It brings a truly explosive feeling to the throwing motion that is unlike anything else I've experienced. The difference between a left side that lags behind and one that assists the rotation will give a completely different feeling to the end of the throw. My right side feels like it's being sprung open by my left upper body, and it gives a strong feeling of late acceleration.
Above is a comparison of my current form (top) and my form back in November (bottom). There are lots of differences here, but the thing I want to focus on is the action of the left side starting right at 35 seconds. Just as the weight transfers to my front foot I bring my left shoulder and arm through to create tension in my upper body that will power my body open through the rotation. Compare that to the bottom throw where you can see that my left side is lagging behind sapping power out of the rotation.
When I worked this into my swing I accidentally did it in reverse, and in retrospect I think that is the best way to go about it. If you are already throwing 350'+ then your backswing is probably adequate, and adding in the unloading, forward action (like McBeth) will be immediately beneficial once the timing is down. The added turn that you get during the backswing from the added loading action only really makes sense once you have a feel for unloading what you already have. As with any motion, I would add this in doing stand still throws before adding it to an x step. Timing is essential, and the x step makes all timing about 10x harder.
One of the difficulties I encountered early on when trying to bring these concepts to my throw is that I would tighten up the rest of my body even though I only wanted to tighten up parts of my left side. When trying to implement this be sure to keep everything (other than the left side during the inward pull of the left arm) loose and relaxed as usual. Tension in your body can only work for you when it's localized with the proper timing.
I hope this helps others as much as it has helped me! As always, any feedback or comments are appreciated. Thanks for reading!