CainIV - 2:23 am on Jul 11, 2011 (gmt 0)
When you say "alone" do you mean if a site's backlinks include ONLY directories and no quality links?
Exactly that. I have tested similar sites, with the same age, similar domain name, and similar content created from scratch, and have tested one of the so called "blasts" of the free directories to put the thing to rest. The website I had dropped to page 8 and has yet to recover (after about 8 months so far).
The other website has about 15 total inbound links and ranks page 2.
And sorry cnvi for the confusion, I agree with your premise.