There are some really great running backs in college football currently. Some include Mark Ingram, Ryan Williams, John Clay, DeMarco Murray and Dion Lewis.... speed,size,weight,strength,and quickness all vary between these backs. Running backs like Mark Ingram or John Clay from Alabama and Wisconsin, are more power backs. The way they think is that they want to run over you rather than around you. They are usally larger than most backs and carry alot of weight. They prefer to stay running between the tackles. Notice that both the teams they are on are both pro style rushing teams, because they dont have the speed to cut it outside they run it inside to set up the pass which means a lot of carries for Clay and Ingram. Power runners can take hits and will stay in games, but usally they are the one delivering the deadly blows. Having the defense take those blows will eventually wear them down and make them tired giving linemen an easy job to make holes. Even though Mark Ingram does not have he real size of a power back he still is one of the most powerful runners in the leauge, if not the most. Clay has the size, and the weight but isnt very fast which hurts him when he is in open space. As you saw from last year speed kills, from running backs like C.J. Spiller out of Clemson, and Noel Divine from West Virginia. With Spiller gone speed went from a machicne gun to a pistol, at least at tail back. Still three backs are left with outstanding speed, Demarco Murray ( Oklahoma) Noel Divine, and Jeff Demps ( Florida ). Speed players would like to run around you and past you rather than going right at you. They are small and very light such as Demps whom is 5 foot 8 inches and only 180 pounds. They like to bounce it outside and use their quick feet to turn the corner. All three of these backs are on spread offenses because they need to see the open space and run right through it. All three of them are also good pass cathers and great special team players. They won't get you the best yards per carry average, but will have a chance at taking it to the house everytime they touch the ball. My personal favorite are the balanced runners like Dion Lewis and Ryan Williams. They can do either one, and coaches love them.If i had to pick the best it would be them.