And a last piece of advice, be carefull when doing jumping exercises etc. on the blacktop. You don't want to end up with shin splints or other injuries.
YES. Avoid doing plyos on blacktop. It messed up my knee bigtime. If you do plyos, do them on the grass, a padded surface, or an indoor court. Blacktop and concrete are the worst surfaces you can do them on.
Button and Sticks... a 30 inch vert is average at best. 34-35 is good... and 37+ is fantastic. Both of you need to work on your Leg strength as well. That will really help with your 2 leg jump and standing vert. Good luck to both of you guys. Plyos by themselves only work for people who have natural bounce... you need to get lifting too if you really want to improve.
does playing basketball on blacktop a lot wear down your knees? someone told me that once. but i play at the park almost everyday, and it hasnt done anything to me.