Is the "auto-routing" created by online flight planning resources preferred by ATC over Direct routing when NO preferred route exists? I noticed that when I use online flight planning resources, they provide an "auto-routing" option for my flight. I also noticed that they are the same between both services so it seems like both are pulling the route from somewhere. Additionally, the auto-route appears to be different than a "preferred route" because, for example fltplan.com will say "No Preferred Routes or Stored Routes" then it gives me (a sometimes crazy) auto-route. 

Are auto-routes predetermined or is it just an algorithm (i.e. nearest intersection/victor airways to destination)?

Extra Credit Question: If there is no preferred route for a given destination, is filing Direct or using the auto-route more likely to get you a "cleared as filed?"
I did some follow up research and also spoke to an air traffic controller and I have a partial answer to this question. 


If the "auto-routing" doesn't make much "sense" and there are no "preferred routes" then the probability of "getting a direct clearance would be fairly high."
The "auto-routing" logic is simply using nearest victor airways from Point A to Point B. (I'm still looking for a source for this, but it seems pretty obvious to me now).