How can you check the quality of a backlink?

[ocelot]

This post is deleted!

[NakulGoyal]

There could be a variety of factors that could influence your rankings and a drop of just 1 keyword is not enough to guage the magnitude of the problem. Did you rankings drop for other keywords as well ? Are you noticing both an upward and downward move in the rankings or just downward ? If downward only, I would suggest you check all your On-page SEO as well as Off-page and do a complete SEO Audit.

Again, don't use a drop in 1 keyword's ranking as a decision maker for other actions.