Real Sports had a segment on a HS Coach in Little Rock who pretty much refuses to punt, and always try's onside kicks. Based on his logic the value of having the ball always out weighs field position and the odds will work out in his favor over the long haul. One example was 4th and 5 from your own 5. The field position gain didn't really reduce the odds that the other team would score if you kicked it, and the odds of picking up the first down more than offset that. His team has punted less than once per year since about 2008 and has about 8 different onside kick formations. They also have multiple state titles in that period. RS backed up his argument with an economist who ran some stats at the NFL level and determined that if you're outside your own 40 you should go for it on 4th down every time if YTG is 8 or less. The message was 1) Coaches are stuck in their ways and 2) They aren't paying attention to statistics. Kind of the Billy Bean story of football.