At one point in my day I avg 20, 8, and 2 (pts, assist, steals) at the jr college level running guard. Before I hit 25 and my back and knees left me, I trained for vert and explosive jumping for years throughout HS and jr college.
My secrets were the reverse elevator shoes and the hydraulic leaper machine. Those together over a year or so put me at 35' vert.
I'm like 5'11 on a good day, lol. I used to love when 6'4 guys would think they were going to block my layup only to end up on a snap shot looking like .....whoaaaa!