I actually haven’t pushed myself to my limit yet, I can probably get over a tennis net with practice but so far I can easily clear 7 boards. I wanted to try 8 but no one was willing to give a board to stack, so that sucks. I don’t really think that height is that important, to me the length and arc matters more, that’s what matters in terms of clearing big obstacles and gaps, you need a ollie that’s high and long. A large trash can is a good start I feel.