that jumped out at me too!
i actually expected it to be the opposite with more homeruns set up in Chan's offense, my recollection being his long runs were much longer then, mostly because they were systematically queued up.
i think, rather, what we're meant to discern from these numbers is that his bad runs went WAY up under marrone. two seasons ago i did a map of spiller's runs which showed, as we expected, that the bulk of his runs came at the extremes. i think in 2013 and 2014, he had a tremendous number of really bad carries which pushed the percentage of his overall production further and further to the top. make sense?
An easy way to determine this would be to look at the percentage of his zero to negative yard runs from 2011 through 2014 give me 10 minutes.
As expected: https://goo.gl/vPhpg4(warning, some of these numbers are ASTONISHING)