My rating scheme:
8 - Tier I [Best stories on the site]
7 - Tier II [Amazing stories which carry emotional weight but significantly worse than 8's]
6 - Tier III [Very enjoyable works of fiction but lack that emotive quality present in 7's]
5 - Not particularly enjoyable but the author put effort in and convinced me that they are a competent writer
4 - The story was not particularly enjoyable but the author put effort in. No sign that they are particularly competent.
3 - The story wasn't very enjoyable, but the author made an attempt. The story was obviously limited in some fashion (like it's a demo, short, no obvious plot, etc.) but wasn't completely linear (no "you can't do that, do this instead" links, etc.)
2 - Author either put next to no effort in, or it was OBVIOUSLY linear (choose this or die / you can't do this links). But there was SOMETHING good about it.
1 - No Effort or Obviously Linear with no significant redeeming characteristics (including humor) but not quite bad enough to unpublish
EXAMPLES
8 - Ground Zero
7 - Necromancer
6 - Tales from the Basement or Geek, etc.
5 - Braak the Briton or Celestial Lies, Chapter I
4 - Bloodlines or Celestial Lies, Chapter 2
3 - Attack of the Grue or Behemoth
2 - Chess Master Stan! or Damn Zombies!
1 - Atlantis or Baby Eddie Game