Where they rank on defense: Week 10

Posted by ESPN.com's Mike Sando

The 49ers have spent big money on defensive free agents Nate Clements and Justin Smith.

They have used recent first-round draft choices for defensive players Patrick Willis, Manny Lawson and Kentwan Balmer.

The investment has bought them the NFL's 22nd-ranked defense in yards allowed. Two teams have allowed more points than the 49ers this season (partially a reflection of turnovers). The 49ers' defense ranks high in red-zone percentage, but the overall performance hasn't met expectations.

Where NFC West defenses finished in yards allowed last season: Seattle 15, Arizona 17, St. Louis 21 and San Francisco 25.