Can you explain a little more about all the different types?
Basically low and high has to do with where your hand is. Think about a low toproll being one where your hand angle relative to the table is closer to parallel while a high toproll is where your hand angle is closer to perpendicular (vertical).
A posting toproll is really hard to explain. I will think about it and see if I can figure out how to explain it.
i was just wondering at some time i have extreamly good top roll with a low grip on his hand why is this most time ppl say get up high on their hand and the best top roll i do is low