Since all position is relative to other points in space, this is irrelevant.
Well, that's if the explosion was uniform.
We must consider:
a) How the matter that the Big Bang released collected and how this influenced its:
b) Eventual release with the advent of the Bang itself.
While the Bang itself superheated everything and melted protons, etc, there would still be a rough form to the ball, it would not have been an ideal sphere owing to the accretion patterns.
why are we suddenly talking about the universe
We are talking about the critical moment of creation that we know of.