Las Vegas Raiders running back Ashton Jeanty dealt with plenty in his rookie season, from Chip Kelly changing course on his stance to running behind a struggling offensive line.Nonetheless, despite the challenges Jeanty faced in Year 1, he was still able to produce for the Silver and Black. Last season, the Raiders star posted a 70.4 overall PFF grade as he carried the ball 266 times for 975 rushing yards and five touchdowns while forcing 61 mis…