The ranking score is calculated by the following formula:
( count ^ 1/3 * eng_weight * pos_weight ) / 10,000
It is an indicator which measures how well a particular web siteís ranking. This is calculated after analyzing the position on the search engine by using the keyword/phrase.
count = Number of sites found by the given keyword by the search engine
eng_weight = Engine weight, weight of a search engine you have set in the "Score" tab
pos_weight = Position weight, weight of a position you have set in the "Score" tab