5'7", could dunk a mini bball or tennis ball. Use to out jump 6'2" guys all the time for headballs in soccer. My college soccer coach stood me up in front of a camp he was doing, had coached 30 years, said he never coached a better player in the air than me(half the campers were taller than me).
Like some mentioned, weights made a huge difference. Was strong in my legs and used to bench 320 in college, weighing 175. Jumping in soccer is like rebounding, not shooting. Bodies hanging off you, need strength to clear space and still go up. Having a good eye for the ball and reaction to where the ball is going is huge as well. If you see the flight or trajectory of the ball before, and you are strong enough to keep your position, you will often win(think Chuck Hayes, Oakley, Rodman-not big guys as per height, but strong bases and strong upper bodies).
Not bragging, just relating my experience and observations. As I broke my back playing soccer, and discovered it years later, I have a hard time jumping over a piece of paper now. You lose timing, strength, etc if you don't stay with it and if time and mileage catch up, and they will.