The Chiefs have worked hard all season to make improvements in every phase of the team. But as they close out the 2009 season, a gigantic flaw has emerged: run defense.

Compared to how badly they had been getting gashed, Sunday was actually a step in the right direction. In a narrow loss to the Bengals, Kansas City allowed 144 yards on the ground, 133 of them to Cedric Benson. But over the course of the club's last four efforts, it has now been burned for 235 rushing yards on average.

While the Chiefs certainly have made progress in other aspects of the game, defending the run has been their Achilles' heel down the stretch, and they now rank 31st in rushing yards allowed on the season. Regardless of what the rest of the team is doing, the run "D" is holding everyone else back.

Head coach Todd Haley was encouraged with the defense's overall performance in Sunday's hard-fought defeat to playoff-bound Cincinnati, but fixing a broken defensive front will be one of his top priorities this offseason after what went down in the final month.

The PFW spin

Although the Chiefs weren't embarrassed Sunday like they were the previous week against the lowly Browns, who ran for an incredible 351 yards, they still struggled with a quality back in Benson. Even though he was dealing with an injury, Benson still had a productive day against a defense that knew he was going to get the ball yet couldn't stop him.

Kansas City's inability to contain the run has limited the progress of a team that at times appears headed in the right direction. After its pass defense was exposed early in the season, the club did a respectable job correcting some of its issues and now ranks in the top 20 against the pass. Similarly, the Chiefs couldn't run the ball at all early on, but with Jamaal Charles in the backfield and some better blocking up front, they now have a dangerous rushing attack that should carry over into 2010. And while QB Matt Cassel has obviously had his ups and downs, his grasp of the offense is getting stronger and should improve a great deal after he has a full offseason to work in the system.

Against the run, however, the Chiefs have regressed. That has allowed opponents to sustain long drives and control the clock, tiring out the defense and keeping the offense off the field. Constantly getting gashed on the ground has had a demoralizing effect on the entire defense. It's no coincidence that K.C. has lost its last four contests.

If defensive coordinator Clancy Pendergast is given another season to further implement his 3-4 scheme, GM Scott Pioli will need to get him better, more physical players up front. The Chiefs went with somewhat of a hodgepodge linebacking corps in 2009, which clearly didn't cut it. They need tough, fundamentally sound 'backers in the middle who can shed blocks and stuff opposing rushers at the line of scrimmage, something they didn't have this season.

Considering how poorly it finished '09, the Kansas City run "D" has nowhere to go but up next year. The maturation of the defensive ends should help. Glenn Dorsey was effective in his first season as a 3-4 end but should only make strides as he learns the nuances of the system and gains more experience. Similarly, rookie Tyson Jackson didn't contribute much in Year One but now has a full season as a starter under his belt, which should be very valuable to him making more of an impact in '10. A step forward from this pair would be huge for the defense in general.

So now it's on Pioli and Haley to first decide if they want to keep this scheme, then go out and get players who can make the defense a more effective unit next season. They obviously have their work cut out for them, but a few shrewd moves could go a long way in returning the "D" to respectability.