The Seahawks run defense has been among the top of the league, not just this season, but every season since Pete Carroll got here (except 2010 after Red Bryant's injury). Scatbacks have occasionally been a problem, but Frank Gore is everything but that. And yet, this happened: 175 net rushing yards on 32 tries for a 5.5 yard per carry average. Frank Gore ran for 131 yards on 16 carries, an average of 8.2 yards. What's more, per ESPN, 107 of his 131 yards came before contact.

What in Frith's name happened here?!

The stats alone tell some of the story. Big gashing runs tend to point specifically to "gap containment" problems. Gap discipline is the concept that every offensive line "gap" needs to be covered by a DL or LB player. Gap containment was a weak point for the 2011 Seahawks only on the outside, never on the A and B gaps (between the two defensive tackles). Yet it's between the tackles that the 49ers pounded Seattle into the ground. And the untouched yards already indicate the rest of the story: Total offensive line dominance.

In last week's audibles at the line on Football Outsiders, Vince Verhei noted the 49ers are "absolutely destroying the record for [Adjusted Line Yards] this season. They're gaining five or more yards on half their carries. Yes, they're probably going to come down to earth before long, but for one-third of a season they've been like nothing we've seen in decades." Well, they're not coming down yet, Vince. This is as good a showcase of runblocking as I've seen since the '05 Seahawks line, easily matching the Vikings of a few years back or the Texans of last season.

How did they do it? Well, for one there was a lot of smart play-design. They'd use trap-blocking (letting a DL pass the line of scrimmage unblocked to "trap" him out of the play) effectively, did nothing but effectively scheme pull-blocks, and beat us on tosses. More than great play design, it came down to the fact that the 49ers almost never needed to double any Seahawks DL, which would consistently leave offensive lineman free to block downfield.

By design, multiple OLers would pull free to block downfield, and LBs aren't often going to win those matchups. The speed at which they'd run these pulls and Gore would hit the hole was astounding. But equally astounding was seeing the center Goodwin winning on his own against Brandon Mebane, or how they'd use a tight end to single-block out DE Red Bryant.

Just let that sink in.

A tight end blocking Bryant on his own and getting enough of him to keep him out of the play. Bryant may have had the worst game I've seen him play since Pete Carroll arrived, but Brandon Mebane and Alan Branch weren't much better.

It's true the game was a tale of two halves, but the main adjustment from the 49ers on offense was for Alex Smith to stop trying to look for the downfield stuff, and instead take well-designed underneath outs. The run dominance from the 49ers was a constant throughout the game, the only difference late was that the defense was too gassed to even put up a fight. The Seahawks got dominated by the best run-blocking offensive line in football, and there's no one even close.

2-3-SF 28 (14:17) F.Gore up the middle to SF 34 for 6 yards (L.Hill, K.Wright).

Delanie Walker helps LT Joe Staley to keep out Chris Clemons by chip-and-releasing. Red Bryant is doubled on the other side by the RT Anthony Davis and TE Vernon Davis. Vernon also chips before the RT seals Bryant out. RG Alex Boone singles up on Branch, getting low and stopping his momentum. The key blocks happen in the middle, as LG Mike Iupati #77 and C Jonathan Goodwin #59 double up and drive Brandon Mebane back. Driven back, Iupati effectively seals out Mebane, which frees up Goodwin to get a piece of Wagner.





The gap between Mebane and Clemons is very inviting for #21, Frank Gore.





2-4-SEA 44 (3:08) K.Hunter right end to SEA 35 for 9 yards (K.Chancellor).

FB Bruce Miller #49 motions before snap. C Goodwin #59, RT Davis #76 and LG Iupati #77 all pull out immediately at the snap. Miller singles up with Clemons. RG Boone singles up with Mebane and holds. LT Staley mauls (possibly holds) Branch. Bryant is simply ignored as the play is run away from him and they don't fear his backside pursuit. The two LBs playing off the line don't play this one great. Hill correctly reacts to the pull-block by following the linemen but is too slow to factor in. Wagner doesn't recognize the play as fast, hesitates and thus arrives late.

Goodwin takes care of Hill. WR Kyle Williams #10 blocks out Sherman very well. WR Michael Crabtree #15 gets *just* enough of Wright to keep him out of the play, a little less there and this play would have been dead.

RT Anthony Davis #76 goes downfield and takes out Wagner. With 5 OLers, 1 FB and 2 WRs the 49ers have accounted for the entire Seahawks front 7, with Iupati with no one to block and Bryant left unblocked out of the play. Wagner's block does get in Hunter's way, which slows him down and allows Chancellor to wrap him up.

This is as well as you can execute a crack-toss. Because of the size of Seahawks CBs and the speed of our LBs, they shouldn't work so well against us, but like screen passes they are something this defense needs to work on.

1-10-SF 16 (11:58) F.Gore left guard to SF 19 for 3 yards (K.Wright).

49ers OL slide-blocks left. RT Davis pulls left as TE Davis blocks out Bryant, RG Boone easily handles McDonald, C Goodwin tries to pull into open field as Boone trap-blocks Mebane inside. LT Staley just straight-up mauls Clemons. Goodwin blocks out Wagner, but Miller misreads the play to the outside while Gore hits the B-gap, leaving Wright free to tackle him. Had Miller not misread, this is another potential big gain.





1-10-SF 40 (9:32) F.Gore left guard to SF 46 for 6 yards (B.Mebane).

This one is not pretty. Seahawks have 8 in the box, with Earl Thomas looking to blitz the A-Gap, and Wright looking to blitz from the offensive left. Vernon Davis takes care of Wright, while Thomas appears to read pass and is surprised by the handoff. RT Davis blocks out Bryant low and hard. Branch is trapped inside and hit hard by the fullback #49. RG Boone #75 pulls and gets Wagner, while LG Iupati #77 finishes off Thomas by sealing him out, but Thomas had essentially taken himself out of the play already.

LB Mike Morgan #57 misreads the play complete and drops to the offensive right flat. Gore is essentially home free, but Mebane fights off the block by C Goodwin for the tackle, while Browner is also there for the stop. Good individual play by Mebane on a play where several defenders misread badly and just mess it up.

1-10-SEA 37 (7:58) F.Gore up the middle to SEA 26 for 11 yards (L.Hill).

LT Staley ignores Clemons to block downfield, while LG Iupati #77 pull-blocks right. Mayock calls Iupati's block a key block, and by play-design it should be. C Goodwin again beats Mebane 1-on-1, while the RG and RT trap Branch by letting him shoot inside. Iupati is supposed to block out Branch on this trap-play, but Branch trips to take himself out, which means his block becomes superfluous. TE Delanie Walker #46 single-blocks out Bryant. Again, by play design 3 guys are free to block downfield. Staley doesn't get anyone, but #75 Boone and #76 Davis hit Bobby Wagner and Leroy Hill.





However, Hill recognizes the play and effectively keeps Davis' block off him to make a shoelace tackle on Gore. This is an outstanding play by Hill in a situation most LBs would lose.

2-7-SEA 23 (6:44) K.Hunter left end to SEA 25 for -2 yards (K.Wright).

Staley pulled out to block KJ Wright, but Wright got juuuust enough for Hunter to kill this play.





No analysis here, but just noting this to give some props to Wright, who probably had the best game of this dominated front 7 with two tackles for a loss.

2-12-SEA 45 (14:20) F.Gore left tackle to SEA 8 for 37 yards (E.Thomas).

The Seahawks are in nickel with Jeron Johnson in for Leroy Hill. 49ers lined up four-wide to invite a pass defense and the Hawks bite on it hard. The DL is a speed-rush package of Irvin, McDonald, Jones and Clemons. Wright and Wagner get lured close to the line. LT Staley and LG Iupati pull-block and Staley's block on Wright in particular is quick, hard and effective. Their pre-snap matchups Clemons and Jones are trapped inside, with RG Boone pulling loose to pick em up as needed. Boone hits an already tripped Jones, while Clemons misses a chance to attempt a tackle by over-committing to the pass-rush. Clemons is the free man here, but this miss is not so much his fault as it is the wrong defensive playcall. RT Davis guards but doesn't need to block Irvin, C Goodwin stonewalls McDonald, while the WRs release, which pulls both the cornerbacks and Kam Chancellor out of the play.

This is a pure playcall win. The Seahawks were reading pass, and the 49ers could effectively block out the front 6 without needing any extra blockers, particularly because the well-executed trap play takes out two Seahawks players (Clemons and Jones) at the price of one blocker (Boone). The three receivers right means Chancellor has to cheat that way or leave a man free.

This play is a nice microcosm of why the 49ers ran on us so well: great play design in trap and pull blocking, and rarely needing to double up on guys, particularly because of the speed and decisiveness in which they run these plays. Earl Thomas' TD-saving tackle is nothing short of miraculous.

The question is not "did the Seahawks get dominated in the trenches?" -- they most certainly did. The question is, what do we take from this? Well, there is some concern at the effectiveness of trap plays and the effectiveness of crack-toss or screen passes against this defense. But honestly, I'm not seeing major reasons for alarm there. The 49ers are simply unmatched league-wide: they have an OL that can single up against any of our huge guys and win, they have outstanding blocking tight ends, and they have a fullback and running back tandem in Gore and Miller that are quick, decisive and have excellent timing.

If they could've run all day on us this game would have been much more one-sided, it's mostly Alex Smith's arm and Kendall Hunter's inferior running that kept the Seahawks in on it. The real story here is the excellence of the 49ers offensive line, and not so much anything troubling in the Seahawks front 7. Even on the rematch at home I don't expect it to be this easy for the 49ers. Keep the LBs further back with better gap discipline and utilize Kam Chancellor in the box (DC Bradley never did, for some reason) and you're looking at a different ballgame.

It may seem puzzling to readers that I'm not more frustrated and worried at such a dominant performance from the opposition. Well, I am frustrated, because it's not fun to watch as a fan. But I'm not worried, because to me this looks more like a one-off storm of perfect circumstances than revealing any major, structural problems. Minor problems, yes. And even with those problems, and with those gaudy running stats, the defense allowed only 13 points to an offense that's averaged 23.5 over the season. Annoyed? Yes. Worried? No.

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