The Jamaal Charles Factor

A strong case could be made that Kansas City's Jamaal Charles has been the best running back in the NFL the past few years. In 2010, he had 1,467 yards. His 2011 season was cut short by a knee injury after two games. He rebounded in 2012 with 1,509 yards. In 2013: 1,287 yards, with 12 touchdowns. Dating to 2008, Charles's career average is 5.5 yards per carry.

Jamaal Charles

This year, hampered by assorted injuries, Charles's number of carries is down, just 182 carries, or 14.2 per game, but his average yards per carry is still a lofty 5.2 for 950 yards, which comes to 73.1 yards per game through 14 games.

Charles has nine touchdowns, which is third in the league among running backs (Le'Veon Bell is tied for fifth, with 7 TDs).

Make no mistake: Charles is key to Kansas City's offense, and he remains a great running back. Still a breakaway threat, Charles has had six runs this year over 20 yards, two over 40 yards, and a longest run of 63 yards for a touchdown.

One knock on Charles, though, is his four fumbles this season. His backfield running mate, Knile Davis, also has four fumbles. Eight fumbles in 14 games from two running backs? That ain't good. By comparison, Le'Veon Bell has zero fumbles.

On the other hand, Charles and Davis score touchdowns: Charles's nine touchdowns are complemented by Davis's six touchdowns.

At 5'10" and a solid 225 pounds, Davis was clocked at 4.37 in the 40-yard dash at the 2013 NFL Combine. He was a third-round pick out of Arkansas. While Charles is a smooth, shifty glider, Davis punches through holes with impact in a straight-ahead, power/speed combination that makes him tough, extremely tough, to knock off his feet.

Davis had a 70-yard touchdown catch-and-run last Sunday against Oakland. Davis is also a lethal kickoff returner -- very dangerous.

Charles and Davis will be a challenging duo for the Steelers to shut down.