The whole 1-10 rating thing got warped years ago. "7" somehow became the midpoint for describing an average woman. That'd be a "5" but no one wants to say that, so everyone became a "7". A "7" would be a pretty decent looking woman. Anything over and above "8" is getting into real head-turning, unusual beauty.
But 8-10 usually appears in the threads where guys are writing about work and their new class, and some "genuine HB9" has arrived, and how do I ask her out, I was CC'd in on an email she sent the other day, does that mean she likes me?! Amazing how many exceptionally beautiful women there are once you've had time to fixate and obsess.
It's all subjective anyway. If you post a pic of your "10" someone will tear her down, the subtext being, he gets better (off PlentyofFish).
When it comes to HB8-HB10s appearing on this forum, I'll reprint the words of Rooster Cogburn: "If I ever meet one of you Texas waddies who hasn't drunk water from a hoofprint, I think I'll shake his hand and buy him a Daniel Webster cigar." With just a little reworking, I'd say the say thing about the claims to having banged HB10s.
If everything starts with a 7, the system is getting screwed up. A 9 might then be an actual 7.