There's a few things involved, basketball running etc provide explosive strain on the muscle which will make it grow quite quickly, theres also the weights route. For me i already had big calves but at one point i was at a job where i walked to work and back and worked 8 hours walking and i wore leg weights on top of me weighing er 120ish cant recall at that point in time, so there my legs got pretty big but more importantly powerful which is an argument for the high rep count method.