I don't know who exactly I am responding to but I object to the idea that one should try to replicate the form. One should perform exercises that improve force absorption instead.
When I first started training 2 footed vertical about 4 years ago at least, I had NO IDEA how to plant off of ONE step, let alone, a full runup with 3-5 steps. It was IMPOSSIBLE to do a running vertical. It was the ugliest fuck ever. Practicing the form helped very little, watching dunk videos also did not help. It took years to understand. Still taking 3 huge steps is something I can barely do. But I can easily do a powerful 1-2 step vert, and the reason why I can plant so much faster, more powerfully, and with a longer penultimate now than 2 years ago, is due to greater eccentric strength, and force absorption, not just because I have thought about the spatial relationships of my joints during the jump mentally for several dozens of hours over the past few years. Squats have helped me, sprinting, and I suppose yes watching videos again and again and again has helped. But 4 years ago, when it was impossible, there was no reactive strength anywhere. Just 3 years ago, freshman year, I also could not physically do it without losing like 3 inches on my vert each time compared to taking a mini step. Only within the past year have I been able to look normal while practicing RVJ. By normal I mean, staying low, planting sideways, and having a noticeable plant foot which hits the ground before the other foot.
Similarly, in sprinting, practicing maximum velocity mechanics gets you almost nowhere without the force producing capabilities typical of an elite sprinter that is developed through strength training and lots of sprinting at near maximal intensities. Practicing the form won't even make SENSE without those force producing capabilities you just will not be able to do it. If you have weak hamstrings, tight adductors and hip flexors it will be impossible to practice max velocity mechanics. Same with acceleration. It's very difficult to practice a low heel recovery if you don't have much quad strength. Build them up and it makes more sense.
Conclusion: Do whatever you want, but you will not improve much by practicing Gerald Greene's form, because you cannot produce force like him, and you will not produce force like him, until you can delineate exactly how he produces force and how much is coming from each joint (ankle, knee, hip), then try to understand how your limb structure and biomechanics can try to replicate that form and then work towards improving the force production or absorption in those areas. (actually you don't need to do all of that, since most elite jumpers jump like Greene). For LBSS force absorption in the hips could help him stay low. Depth jumps jupming backwards and bounding will help. But forcing yourself to plant sideways a little more may help load the hips. You may not jump as high but that doesn't matter it's about training the hips at that magical 90 degree angle elite jumpers maintain during the amortization. (edit: btw when I say you it is meant generally and not to any one individual).
Regardless, Greene doesn't seem to jump THAT differently or differently at all from other elite jumpers. It does seem like his plant foot is less flat footed but he transitions from flat foot to forefoot by the time the other non-plant foot makes contact with the floor, allowing for both feet to take off simultaneously. Doesn't sound too crazy if I got that right. He also plants sideways a little bit which is very natural. He also does the twisting supercoil technique that sickenvendetta talked about. jk about the last one.
