Colts’ hidden treasure: Running backs

Examining a position group that could exceed its preseason expectations:The Colts head into training camp with a lot of holes. Even groups that might qualify as strengths have questions -- are Dwight Freeney and Robert Mathis going to fare as well playing at least some of the time as outside linebackers? Will rookie tight ends Coby Fleener and Dwayne Allen going to be as good as expected?It’s not easy to pick a spot that could overachieve, but I’ve settled on running back.