themaninthejar - 4:34 pm on Mar 14, 2013 (gmt 0)
Google's help section has this to say about Average Position:
"To calculate average position, we take into account the top ranking URL from your site for a particular query. For example, if Janeís query returns your site as the #1 and #2 result, and Davidís query returns your site in positions #2 and #7, your average top position would be 1.5."
Not quite sure what to make of that...