The West Virginia football team has made many changes through Dana Holgorsen’s tenure as head coach. The change made at the running back position may be the biggest of them all. Here are the differences each year under Dana Holgorsen.2011 406 rush attempts – 541 pass attempts2012 451 rush attempts – 537 pass attempts2013 427 rush attempts – 466 pass attempts2014 563 rush attempts – 534 pass attempts2015 622 rush attempts – 429 pass attempts2016 574 rush attempts – 409 pass attemptsTakeaway: The Mountaineers have become a more balanced offensive team over the past six years. Dana Holgorsen has always been recognized as a seasoned pupil of the Air Raid offense created by Hal Mumme, but he has since left that table to better compete in the Big 12. Teams like Oklahoma State, Texas, and Oklahoma have thrived as perennial Big 12 leaders behind both a stellar passing and ground game. Understandably, the addition of Will Grier under center has led to a strong sense of nostalgia to days when the Mountaineers averaged 502 yards of offense in 2012, but one thing has become clear. The Mountaineers cannot win a Big 12 Championship without a balanced attack. Just last year, the Oklahoma Sooners rolled out receiver Dede Westbrook, quarterback Baker Mayfield, and running backs Samaje Perine and Joe Mixon en route to its 46th conference title.The Mountaineers finally have a chance to bring home its own Big 12 title with the stable of running backs it has returning. ESPN Big 12 writer Mitch Sherman recently ranked this West Virginia group as the best of the Big 12 regardless of position. Let's break down the Mountaineers ball carriers and what to expect in 2017.Justin Crawford (Sr.)- There is undeniable cause Crawford was named the 2016 Offensive Newcomer of the Year. The JUCO product was brought to Morgantown to aid Rushel Shell in his attempts to replace Wendell Smallwood, but it was Crawford himself who did the heavy lifting by season's end. For 2016, he rushed for 1,177 yards on 162 carries including a career-best 331 yards against Oklahoma. He averaged 90.5 yards a game and found paydirt on four occasions. Look for Crawford to average more than 100 yards per game and over 10 total touchdowns now that he is the lone feature back for the Mountaineers.Kennedy McKoy (Soph.)- McKoy has already been named the most versatile back of the bunch by Holgorsen. The sophomore has a perfect blend of speed and power to produce great results for the Mountaineers. As a true-freshman, McKoy rushed for 472 yards on 73 carries while adding four touchdowns. His experience as a freshman will serve as a great springboard into 2017 as McKoy becomes the perfect compliment to Crawford. It wouldn't be surprising if the sophomore rubs elbows with a 1,000-yard season.Martell Pettaway (Soph.)- Like McKoy, Pettaway will also contribute as a change of pace back for the Mountaineers, however, this pace includes bowling you over en route to a touchdown. The biggest back by weight, Pettaway will be heavily relied on in the red zone now that Rushel Shell has graduated.Tevin Bush (Fresh)- Despite a loaded backfield, Bush's escapability should allow him to see the field early. While Mountaineer fans haven’t seen him in action, Bush will give the fans plenty to be excited about. In high school, Bush had over 2,500 all-purpose yards as a senior. Look for him to find his niche early as a return man and in the slot while his counterparts eat up a lot of the carries.