Dissecting Most Crucial Matchups in 49ers' Week 9 Contest with Rams

Running the ball and stopping the run are staples of the San Francisco 49ers under Jim Harbaugh. To dominate the trenches against the St. Louis Rams in Week 9, they'll have to make some adjustments from their 31-17 Week 6 win in St. Louis.

In that game, the Niners were outrushed 93-89. They were bailed out by Colin Kaepernick's best performance of the season and Janoris Jenkins' mind-numbing mistake on Brandon Lloyd's 80-yard touchdown catch right before halftime.

The Niners undoubtedly dominated the second half, but who knows what would've happened had the first half ended 14-3 instead of 14-10. 

Getting the ground game going, and taking pressure off Kap in the process, will be one of Sunday's keys. Protecting Kap and taking advantage of St. Louis' injury-ridden offensive line will also have an impact. 

The following matchups—either player vs. player or player vs. positional grouping—will play a big role in determining Sunday's outcome.

Justin Smith vs. left side of Rams' line

Offensive tackle Jake Long suffered a torn ACL on Sunday. The injury will keep him out for the season. 

Center Scott Wells and guard Roger Saffold are also banged-up. Suffice to say, the Rams' offensive line is mess right now.

The last player it'd want to face is Justin Smith. 

The five-time Pro Bowler is capable of wrecking a offense's running game and passing game. 

He'll get his shots at rookie Greg Robinson, who will be starting at left tackle in Long's place. 

	On Run Plays	On Pass Plays	Overall
Smith	+11.3	+0.3	12.2
Robinson*	+0.8	-1.9	-0.2

Smith did enough damage with three quarterback hurries and two stops (solo tackles on plays Pro Football Focus deemed were offensive failures) in the first meeting. The Rams, who already had plenty of issues moving the ball in Week 6, can't afford to have Smith dominating the trenches even more. 

Joe Staley vs. Robert Quinn

Like the 49ers (with Smith), the Rams have a player capable of ruining an offense's game plan all by himself. 

Robert Quinn has 32.5 sacks in his last three seasons. He's had three sacks in his last two games. He's one of the most dominant pass-rushers in the league. 

However, Joe Staley has owned him since the start of the 2013 season:

Date	PR Rating	Hurries	Sacks
Week 4, 2013	-0.8	2	1
Week 13, 2013	-0.7	3	0
Week 6, 2014	-2.2	0	0
Totals Since '13 Week 1	+69.5	64	22

With Quinn quiet, the 49ers have comfortably beat the Rams in their last three meetings. Kaepernick has tossed six touchdowns and zero interceptions in those games. 

If Staley wins that matchup again, the 49ers might just have another huge offensive performance. 

Frank Gore vs. Rams front seven/eight

The Rams sold out against the run in Week 6. And they got the desired effect—they took away Frank Gore (16 carries for 38 yards). 

However, they were repeatedly burned by Kaepernick's passing (343 yards and three TDs on 35 attempts). 

I expect the Rams to reduce their aggressiveness in stopping the run to focus more on limiting big plays in the passing game. If so, Gore must be more efficient. 

In the Week 6 game, Gore wasn't all that productive even when he faced seven or fewer defenders in the box:

Defenders in Box	Carries	Yards
7 or Fewer	9	37
8 or More	7	1

That has to change for the 49ers to consistently move the ball against the Rams...or any NFL defense. 

The good news for San Francisco is left guard Mike Iupati (concussion) has been cleared to play, per Matt Maiocco of CSNBayArea.com. 

The 49ers have yet to play a full game with their starting guards (Iupati and Alex Boone) and tackles (Staley and Anthony Davis). 

They'll have their hands full getting the ground game going against defensive linemen Aaron Donald (plus-11.6 PFF run grade) and William Hayes (plus-6.1).

Prediction

When the Rams run the ball effectively, they have the potential to give good defenses problems. 

They had the 49ers on the ropes in Week 6 in the first half. They beat the Seattle Seahawks the next week behind 102 rushing yards. 

But with their offensive line banged-up and the 49ers healthier from their bye, the Rams are going to have issues running the ball. And that will allow San Francisco to tee off on Austin Davis, who was sacked seven times against the Kansas City Chiefs last week. 

With the second half of Week 6 still fresh in my mind, I have no reason to suspect an upset. Unless Quinn takes over the game, I see the Niners winning rather comfortably at Levi's Stadium.

49ers 27, Rams 13 

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