So, what am I talking about?

Between ~4 and ~10AU:

• 1-10km objects form by two-body accretion or gravitational instability.

• Big guys grow faster than small guys run away.

• Theory predict we should end up with 4 cores (which are like Uranus and Neptune).

• Largest core(s) start to accrete gas from solar nebula.

• Remaining cores gravitationally scattered by growing gas giants.

• Their orbits circularized by trans-planetary disk.