That question has been asked almost as much as who will the Colts target in the draft and free agency.
There is no answer at the moment, and there may not be one until training camp or even up until Week 1.
It's not that the Colts are keeping it a secret. They don't have an answer, either, because the two running backs under contract -- Richardson and Ballard -- are both dealing with injuries.
Ballard tore his ACL in practice early last season, and Richardson had a shoulder procedure after the season ended. Richardson isn't expected to miss any of the offseason workouts, and the goal is to make sure Ballard is ready for training camp at the end of July.
Ballard rushed for 814 yards during his rookie season in 2012. The main reason the Colts acquired Richardson is because Ballard suffered the knee injury prior to the Week 2 game against the Miami Dolphins. Richardson ran for a disappointing 458 yards last season.
“At any point in time you'll know how we do things with the Colts, it's the best players play,” Colts general manager Ryan Grigson said. “Iron sharp as iron. We're going to try to have the most competition at each position group and whoever wins that spot is going to be the starter and it's who is going to get us to that next level, which is Super Bowl XLIX and that's the mindset. You're either all in or all out."
Who starts won't mean much if offensive coordinator Pep Hamilton has his way. He wants to have a two-headed attack in the backfield. There are few teams in the NFL -- Minnesota is one of them -- that can rely on just one running back to carry the load.
Richardson had a team-high 157 carries last season and Brown had 102 attempts.