I thought last season that Biffle had the best shot at it. I also thought that Sprague would figure into the deal before the season played out.
At this point I can't give a real edge to anyone. Early last season many figured JJ had it locked up and we all know how that turned out.
Biffle and McMurray with their experience and the teams behind them are the front runners. Jack has the 'sperience, though he has a history of trouble, but the team likely does not match up to the other two.