What does it mean?

Position from 50 to 600 within one week on google, nothing changed, why?

[hotice_2002]

My website is always within top 50 on google with one special search term, and kept the position for about 6 months. I know google is updating, yesterday when I search my website, I can not find it any way. Later I found it at 600th with that special search term. I can not understand why google changes so much, I never change my website, my website ranking is never change still is pr5. I want to know who have ever met this kind of thing. Who know answer? Who can help me? Thanks!

[Brett_Tabke]

It's the norm for results to vary month to month with most search engines. Google has had the most stable rankings of all the se's. When they do tweak the algo like they did last month it can impact everyone.

Pretty much continued over here:

[webmasterworld.com...]

[Randex]

Google apparently did more than tweak the algo.
A lot of very serious impacts have been discussed in these
forums.
Fair? By whose definition?