Has anyone ever calculated this? 

I know it depends upon a lot of factors such as prestige, distance and quality of the recruit.  Let's assume the baseline is an A+ prestige school went after a no star recruit (D1) that was 10 miles away, how many HV's would it take to get to *very tight*?  This is also assuming that the school is not involved in a battle and the recruit did not list them as their childhood favorite or had a distance preference. 

Also how many more would it take to get to *very tight* for every distance further away and lower prestige for the same recruit?  ie) how many HV's would it take for a C prestige school take for the same recruit?  Or how many HVs would it take for an A+ to be *very tight* with a 5 star recruit?