One of the most overlooked 'actions' in a swinger's motion is the bent right wrist. During a swing the left wrist only cocks and uncocks (via the right forearm) and the right wrist only bends.
Most hitters have that bent right wrist down pretty well. Starting from impact fix tends to help give the feel for that bend, but swingers often get caught up with swivel and, while understandable, the focus is on the flat left wrist.
It is far easier for most people to learn to focus on a bent right wrist and maintain it - hence also having a flat left.
It is the 'wheel rim' feel, the maintenance of that bend in the right wrist.
For those of you struggling to keep good compression, shift your focus to maintaining that bent right wrist. It will help you understand the 'magic' of the right forearm.
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Simplicity buffs, see 5-0, 1-L, 2-0 A and B 10-2-B, 4-D, 6B-1D, 6-B-3-0-1, 6-C-1, 6-E-2