Why do some Keywords collapse in SERPS?

[Zippy-Bungle]

I've been working my way up SERPS with some fairly uncompetitive keywords and have been comfortable with them in the 5-10 range. This week I have watch a number of them drop back to the mid 50s.

Why?

[benjaminmarcinc]

HI, Are you talking about the local serps? It might have been the new algorithm change that was recently updated. I have notice some updates as well.