jd01 - 9:13 am on Apr 9, 2007 (gmt 0)

I think what could be happening to some "quality" site might be attributed to the change in the way links / link text are applied and the better detection of "scraper spam". (I think someone noted there was a change earlier in this thread.)

I don't know if you can count link text as part of the document they refer to in a phrase based system the way you could in a boolean based system, because it seems you could "throw off" the expected phrase(s) calculations for the receiving document.

So, where certain types of links may have been helpful to some sites previously, it would seem reasonable "removing" the keyword(s) patterns from the receiving document could negatively impact rankings.

Also, I believe "scraper spam", which was previously undetected as spam would have counted as an inbound link, so I think it's possible "scraper spam" links actually helped some sites, and when the counting of links was adjusted, and/or the sites were detected as "spam" some sites probably lost large amounts of "links" or "link text" and went into "free fall".

Justin