Dividing Pizza dough to balls before baking I see in a lot of recipes for Pizza baking that you need to divide the whole mass into several balls before the first proofing or before you make the pizza. I find it more convenient to just have the whole mass together until I actually need to bake and then I just take a chunk and leave the rest in the container.
Anyone know why they recommend dividing it before? What's wrong with the method I mentioned?
Probably so that the gluten can relax before you go for the final forming. 

By forming it into a ball you are starting it towards "pizza pie disk shape" from "formless mass of dough." If it rests for 10 minutes or more in that shape, proceeding to further shape it into a disk will go easier (and further, if desired), with less spring-back from the gluten network.

I use roughly the same process in making bagels or long strips for braiding. You can work it until it just won't go anymore, take a break, and come back to find it pliable and willing to stretch further.