So, here is where we stand:

		Dynamics OK?	Other OK?
I:	Sweeping Mean Motion Resonances	NO	maybe
II:	Sweeping Secular Resonances	Yes	NO
III:	Scattering by a Planet	Yes	Iffy
IV:	Secular Resonance with an Inclined Planet	Yes	Iffy
V:	Binary Star	Yes	Maybe
VI:	Passing Stars	NO	.

• Interactions with a planet scattered out from inside the Kuiper belt could explain what we see.
  • But, there are timescale issues.
  
  
• A primordial binary companion could do it.
  • But, why then did large objects grow in the KB?