For some reason one of my old coaches, Mike Agostini (Vancouver 1954 Comm Games 100 yards champion) from Trinidad, got to meet Borzov a few years after Valeriy won the double in Munich 72. Agostini said Borzov demonstrated the “Borzov Hop” but that version did not have the back foot on a ledge. The whole movement was vertical as in this video with vigorous double-arm action. It is definitely in the category of plyometrics. The Borzov Hop I was shown by Agostini used alternating lead thigh/leg, but I’m sure you could come up with any variation you like. We also did “Indian Hops” which were basically little “jump-squats” hamstrings parallel, forwards and backwards with arms straight out in front. They were quad killers. Nasty but relatively safe, esp compared to the single-legged Borzov Hops. Apparently the Indian Hops were a traditional staple in training of the old grapplers (wrestlers). Important of course to brace (contrract) abs and back during any plyo training.