What once looked like a 49ers weakness now appears to be a strength.
After getting shredded by the Bears and Cardinals in the second and third weeks of this season, the Niners defense looked nothing at all like previous versions under head coach Jim Harbaugh and defensive coordinator Vic Fangio.
The unit was struggling to come together after the loss of nose tackle Glenn Dorsey, linebackers NaVorro Bowman and Aldon Smith and cornerback Tramaine Brock.
But over the past two weeks, both victories, the 49ers defense is excelling once again. Against the Eagles – who feature the NFL’s rushing leader last season, LeSean McCoy -- San Francisco allowed just 22 yards on the ground. Then last week against the Chiefs’ formidable 1-2 punch of Jamaal Charles and Knile Davis, San Francisco allowed just 107 yards.
The Niners now rank No. 2 in the NFL in total defense, giving up just 282.8 yards per game and are No. 5 against the run, allowing an average of only 77.2 yards.
One of the reasons for the success is the play of Ian Williams at nose tackle, Michael Wilhoite, Dan Skuta and Aaron Lynch at linebacker and Perrish Cox at corner.
For Williams, this season has been a sweet comeback.
The former Notre Dame standout won the starting nose tackle job in the 2013 training camp but saw his season come to an end in Game 2.
Now he’s worked his way back and taken over for Dorsey, who should return later this season from injury.
When the 3-2 49ers take on the 1-3 Rams in St. Louis Monday night, Williams will no doubt again be tested.
But in selecting its First Quarter (of the season) NFL All-Star Team last week, Pro Football Focus chose Williams as its nose tackle.
“What’s not to like about Williams?” wrote Khaled Elsayed of PFF. “Maybe he could do with more playing time, but lining up as a more traditional nose tackle gets him extra marks. He’s been a quiet revelation in San Francisco.”
Williams has 10 tackles, a sack and a batted pass in five games, but his contributions go beyond the stat sheet. The 6-foot-1, 305-pounder has been getting penetration, pushing back blockers and allowing the linebackers to make plays. Even with an injured ankle that limited him in practice last week, he was able to play well against Kansas City.
Niners defensive end Justin Smith says Williams is a big reason the 49ers run defense has been successful.
“Trust me, teams are trying to run directly at him,” Smith told the Sacramento Bee’s Matt Barrows. “They’re not getting the movement on him that they want. That’s why they’re going to the edges. He’s strong at the point and he’s fast at pursuing. That’s what makes him a really good nose.”