I was reading that as you get "better" and "stronger" at squatting, you produce more force, and accelerate the bar more out of the bottom. The better you get, the more force you produce fast, out of the bottom. This means you "cruise" through the top of the range of motion. The "better" you get, The more you blast out of the bottom, the more you "cruise"!
If you add the quarter squat, you are teaching yourself to drive at the top. This is supposed to teach you to keep applying force, or keep blasting longer, in the full range squat.
Which in turn I guess teaches you to accelerate longer, before your take off in the vertical jump?
Then, if you produce more force, each step is more powerful when you run?
Some Russian guy said put elastic cables on the bar
Dr Squat said CAT