I thought I understood but it seems that I missed sopmething...
I have a big number of balls flying around in my game and I thought if they share the same material and belog to the same parent gameobject the also share one draw call.
but my statistics window still count the same amount of draw calls like there are bally flying around...
Use this script link text. You must have the same material on the objects. Not only will you have your draw calls with those objects reduced to 1 they will also be batched as 1.