Tennessee Titans enthusiasts have a love-hate relationship with Chris Johnson. An example of that came when the Titans hosted the New York Jets on Dec. 17, 2012. Johnson had 21 carries for 122 yards. Fans loved Johnson on his 94-yard touchdown scamper. They weren't excited about his other 20 carries: 28 yards.

That inconsistency drives fans insane. Some fans prefer a more-complete running back who relies on more than big plays. They want someone who can grind out the tough yards. If this were compared to baseball, these fans would prefer the five-tool outfielder who doesn't dominate any statistical category over the player who offers nothing more than 40 homers.

The running back pool is fairly shallow. Pro Football Focus has compiled a list of the top free-agent running backs of 2013. Danny Woodhead (10.4) and Steven Jackson (9.3) have the highest ratings. Javon Ringer (-1.7) and Darius Reynaud (-1.1) are toward the bottom of that list.