When Jim Harbaugh was head football coach of the Stanford Cardinals, he would ask his players to name the one thing you have to do to make an NFL team.

They would answer: you have to be talented. You have to work hard.

And Jim would reply that working hard and being talented weren't enough.

Instead, he would tell them, "The one thing you have to do to make an NFL team is take another man's job away from him. And those men really like those jobs."

As we approach training camp, we must all realize that the battles revolving around each position are not merely trivial matters. Instead, players embroiled in these competitions will be duking it out for playing time, for roster spots, and -- ultimately -- for their livelihoods.

And with the average career length for running backs being just 2.57 years -- the shortest among all skill positions -- these players just might have the most to gain and lose from these contests.

With that being said, let's take a look at five situations where the running back pecking order will be heavily contested this offseason and which players will have the most at stake in these battles.