The Big 12 lost several top running backs this offseason, including Doak Walker Award winner D'Onta Foreman. But there is still a talented crop of rushers in the conference. But who are the best of the best? Let's take a look.1. Justin Crawford, West VirginiaCrawford is the returning leader in rushing yards per game in the Big 12 even though his 163 attempts last season were less than any of the other top eight finishers in the category.