tedster - 6:20 am on Feb 15, 2011 (gmt 0)
I thought this was a helpful video. The question comes up a lot, and those of us in the webmaster community couldn't see the bigger patterns very clearly.
It still leaves me a little hazy about the difference between an algorithmically applied penalty and an algo change that caused a natural ranking drop - one that's not a penalty. But I guess we're not supposed to perfectly understand everything. I can fill in the blanks pretty well, I think.