NCAA pitching

[shipwreck]

I finally am getting a chance to do some college women's fast pitch. I just got my rules book and here is a very simple question. How many feet have to be on the pitching plate at the start of the pitch? It seems like the rule says both feet must be on the ground in contact with the pitchers plate and at least half of the pivot foot must be on the top surface of the pitchers plate. What does it mean to be on the ground and in contact with tho pitchers plate? Dave