X factor: Felix Jones, Cowboys RB

In the 2008 draft, the Cowboys were trying to decide between a feature running back in Illinois' Rashard Mendenhall or a complementary back in Arkansas' Felix Jones. With Marion Barber having just made his first trip to the Pro Bowl, the Cowboys went with Jones, and it appears that they made the correct choice.

After losing a large portion of his rookie season to injuries, Jones emerged as the Cowboys' biggest X factor on offense in '09. He's the home-run threat that offensive coordinator Jason Garrett had been missing in the running game. Jones is not a running back who needs 20 carries to find his rhythm. He can break open a game on one carry, and that's what makes him one of the most-dangerous players left in the playoffs.

In back-to-back weeks, he put an overwhelmed Eagles defense out of its misery with long touchdown runs in the third quarter. In Week 17, he took a toss around the left side for a 49-yard touchdown. And in Saturday's wild-card playoff game, Jones broke free for a 73-yard touchdown to make the score 34-7 and end any hopes of an Eagles comeback.

Of course, the rally cry in Dallas now is to increase Jones' carries. It's a knee-jerk reaction that is completely unnecessary. Jones doesn't require a lot of carries to be productive and you don't want to expose his relatively slight frame to a lot of punishment. The offensive linemen on this team love him because he gives them more margin for error. With Barber in the backfield, linemen need to stay with their blocks for an extended amount of time in order for him to accelerate through a hole. All Jones needs is a tiny seam and he's off to the races.

Jones hasn't yet become a breakout star in the league, but he gives the Cowboys rare speed at running back. With the ability to run the ball early in games, quarterback Tony Romo has found a lot of open receivers in the first half. More than any other player left in the playoffs, I believe Jones best fits the description of an X factor.