One of my initial thoughts immediately after the game was, "the defense played well, but our corners stink". After reading Kegbearer's excellent article on the defensive effort, I re-watched some of the game, and decided that the cornerbacks didn't play too horribly outside of a few blown coverages. Unfortunately, I wasn't able to really verify what I thought I was seeing, as the All-22 film doesn't come out until Wednesday. After reviewing the All-22 film, I think my revised opinion was right; our corners actually played pretty darn good football. Here is a breakdown of the 26 defensive plays from the first half, with a focus on the cornerbacks.
Please Note: I didn't keep track of penalties, so the number of plays might not add up with the official boxscore.
Play 1: San Francisco comes out in a two WR set, on Claiborne's (L) side. Claiborne lines up on the line. Carr remains over on the right side, indicating zone coverage. The play is a WR screen to the inside receiver, Claiborne does a good job holding his position against the blocking WR, and Rolando McClain comes over to make the stop. Minimal gain. Of note, Wilcox is in position to make the tackle immediately after the catch and misses the tackle.
Play 2: Bunch formation to Carr's (R) side. Claiborne plays press man. Claiborne has really good coverage, but is called for a penalty. I personally think all contact was within 5 yards, but Claiborne has a reputation and will not get the benefit of the doubt on any close penalties, especially with the increased emphasis on defensive holding this year.
Play 3: Both corners play press man. Claiborne completely misses on his press, and actually falls down. Carr does a good job rerouting but gets beat inside (something that happened to him a lot this game) for a big gain. Dallas actually had really good pressure on this play. Which is a good and bad thing; pressure from the line is good, but last year there was a lot of talk about how if we just started getting pressure it would really help our corners. It did not on this play.
Play 4: San Francisco's first TD. Claiborne looks to be in man coverage, with zone on the other side. Claiborne plays his coverage well. Carr carries one defender into the deeper zone, and passes him off as the receiver goes towards the middle. As that is happening though, TE Vernon Davis goes past the short zone being played by Wilcox and into the intermediate zone Carr has vacated. Wilcox doesn't drop into the deeper zone, even though there is no longer a receiver to threaten the short zone, and Carr can't recover fast enough, resulting in a TD. It's not necessarily a blown coverage, more like a well executed offensive play, but afterwards Wilcox looks at Carr and taps his chest as if to say, "my bad".
Play 5: San Francisco has recovered a fumble and now has the ball on the 2-yard line. And Harbaugh, stupid coach that he is, out-thinks himself and decides to pass! (Sorry for the snark, I couldn't help myself). But yes, the 49ers do indeed pass on first and goal from the two. The 49er's come out with a multiple TE set, bunched together on the right side. Vernon Davis initially blocks down, but then releases. Wilcox doesn't notice and doesn't drop to cover him. Justin Durant does notice and begins heading in that direction, but is on the opposite side of the formation and he can't get there in time. Touchdown.
Play 6: San Francisco comes out twins left. Carter slides over to cover. Claiborne is playing on the line, Carter is about 5 yards off. Run play.
Play 7: Again, twins left. Safety comes down on the coverage. I'm not sure what is said, but it appears Claiborne makes some kind of coverage call. Both players are off the line. QB scramble to the right side, minimal gain.
Play 8: Another twins left. Carter comes over in coverage. Claiborne plays on the line. It looks like man coverage, both players play well; incomplete pass.
Play 9: 49er's come out with 3 WR, slot to the left. Claiborne gives a big cushion (about 10 yards), Carr plays up on the line. Claiborne immediately drops deep on the snap, looks like he is playing deep zone with the nickel back playing underneath. Carr is playing the short zone. He gets beat on the comeback route, but by the time his receiver gets open Kaepernick has already thrown the ball to a crossing TE. The TE is crossing in front of Durant who is actually dropping in the opposite direction. Durant slips while changing direction, but recovers to make the tackle.
Play 10: The 49ers come out with a bunch formation to the strong side. Claiborne is playing on the line on the weak side, and we have a single high safety (the other safety walks down towards bunch formation). Run play for minimal gain.
Play 11: San Francisco comes out in an empty backfield. Balanced formation with two TE on either side of the line, and two receivers outside. Dallas is in nickel, with DB's playing about 5 yards off. Good coverage, pass is complete on a little slant to TE in front of McClain.
Play 12: San Francisco is in 3-wide with the slot to the left. Dallas responds in their base defense with the LB cheated out towards the slot. 3-yard cushion by the DB's. It appears to be man coverage, and San Fransisco runs a read option with the QB keeping the ball for a minimum gain.
Play 13: San Fransisco again comes with 3-wide, slot to the left side. Both DB's play with about a 9-yard cushion. Carr plays underneath zone, Claiborne drops deep. Completion to the underneath zone on the left side. This was an interesting play, the zone was vacated by a blitzing Durant with Carter coming across the formation to cover it. Carter can't get wide enough and the receiver catches near the sideline for eight yards.
Play 14: 49ers come out with a single WR to the strong side. Carr plays close to the line. The play is a straight up option play to the right. The pitch is forced and Carr does a good job fighting off his block to tackle the option man for no gain.
Play 15: San Francisco comes out with three backs in the backfield, and the split end to the left with a tight split. Not sure if it's Claiborne or Moore covering him. Whoever it is, the coverage is pretty bad. The WR runs a crossing route, about eight yards deep. The cornerback is playing man, over the top about half a yard, with the linebackers in zone underneath. That's not too bad, but the corner gets beat inside so he's trailing by about a yard and a half. Luckily Carter is blitzing and gets the sack.
Play 16: Another 3-wide slot left formation. Again Claiborne gives about a 10 yard blanket and drops into deep coverage, with the nickel (Moore) playing the shallow zone. A receiver comes into Moore's zone, and he runs with him for a bit before passing him off to Claiborne deep. As that is happening Kaepernick takes off and scrambles into the zone vacated by Moore for a minimal gain.
Play 17: This is a 3rd and long play with everyone playing a deep prevent. San Francisco drops the ball underneath for a minimal gain, 4th down.
Play 18: After another interception San Francisco gets the ball back with good field position. They come out with a bunch formation right, split end left. Claiborne and Carr play press coverage. Pass is incomplete, and is hurried by a blitz from Justin Durant.
Play 19: San Francisco comes out in a two tight-end set. Both Claiborne and Carr play press man, and do a really good job of rerouting their receivers. Pass is completed for a minimal gain to the TE.
Play 20: San Francisco comes out with trips right. The safety comes down to cover, and Carr is playing with about an 8-yard cushion. Carter cheats over from his SAM position but appears as if he will blitz. Run play to the left for a small gain.
Play 21: San Fran is 3-wide and for the first time the slot lines up on the right side. We generally saw the nickelback come in when the slot was to the left but this time we stay in our base defense with sliding over to cover. Claiborne is on the line playing press-man, Carr is playing about five yards off. San Francisco runs left. I'm not sure if Claiborne is actually blitzing on this play or just reads the run very quickly, but he immediately shoots in, and splits the gap between two blockers to meet the running back in the backfield. Unfortunately he can't make the tackle, but he slows the play down long enough for Barry Church to get there and make a stop for no gain.
Play 22: San Francisco lines up bunch right. Claiborne is in press coverage on his man. Carr is playing about seven yards off the bunch. The safety walks up in coverage and a linebacker (or nickelback, I can't read the number) is a little of the line. Claiborne gets beat with a quick inside move, but is able to recover and has good coverage. Off the bunch there is some interesting stuff going on. It looks like the safety is playing man and goes with his receiver. The nickelback/linebacker blitzes off the bunch formation, and another linebacker comes over to fill the zone. Carr drops to a deeper zone. I don't know if Carr drops too deep or if the help linebacker drops too slow and shallow but a receiver finds the empty spot between them for a long gain.
Play 23: Another three wide slot left formation. Dallas stays in their base formation with two deep safeties and the linebacker coming over the slot receiver. Claiborne and the LB give a five yard cushion. San Francisco runs left. The LB (I think it was Carter) is unable to get off his block. Claiborne is able to hold his ground, and shed the block to make the tackle. Five yard gain.
Play 24: Again with the three wide formation this time slot right. Claiborne is giving a five yard cushion, Carr about three. Base defense, cover two. Zone coverage, completion to Anquan Boldin crossing in front of the linebackers.
Play 25: San Francisco comes out with three WR's all to the left of the formation. Carr is on the line to the right, lined up outside the TE. Claiborne is playing with a 10-yard cushion, and the LBs cheat over to the left side. Play is read-option run up the middle for 10 yards.
Play 26: Exact same set up, by both offense and defense, with the exact same result, ending in a touchdown.
Putting it Together:
Dallas actually ran a much more complex coverage scheme than I initially thought, with a mixture of man and zone, (and some zone/man combinations!). It was interesting to note that, much like Seattle does with Richard Sherman, Carr and Claiborne each played a side of the field, and did not follow the wide receiver. Dallas also wasn't hesitant to blitz off of coverage and use a linebacker to drop into the vacated zone, something I've never heard of Marinelli doing before.
I'm also not sure if it's something we'll see going forward. All three of the biggest pass plays in the first half came off of some confusion in the zone handoff; whether it was not dropping deep enough on the shallow zone to hand the receiver to the next zone, or dropping too deep while passing a receiver off and not being able to recover when another receiver entered your zone. Regardless of where the mistake was, San Francisco did a good job of flooding zones, not all at once, but with staggered routes, forcing our corners and safeties into making bad decisions vertically. Is this the result of our starting corners missing so much time in training camp?
Outside of those few blown coverages, our corners did a pretty good job. Claiborne tripped once when he missed a press and got beat inside once, but was able to recover. More importantly, he showed some impressive physicality in the run game, which was a big question coming into the season.
I actually thought, at least in the first half, that Claiborne outplayed Carr. Carr seemed to be just a step too slow on any real change of direction move. When he was able to redirect the opposing WR he did a good job, but I thought he struggled more in his zone awareness than Claiborne. On the plus side though, he also showed good form and aggressiveness in the run game.
I haven't broken down the second half yet, but after watching it a few times I do have a few quick observations. We played much more zone in the second half, probably because we were playing to stop the run game. And while Carr and Claiborne get a lot of flack as bad zone defenders, they didn't play terribly. Neither made any splash plays, and they allowed a lot of catches, but in theory that is what you are supposed to do in zone, allow catches in front of you, and don't let anything behind you. By and large that's what our corners did. It's an aggravating scheme to watch, but there are reasons for it, and our corners executed it fairly well.
In conclusion, observing the corners more closely reinforces the general takeaway from Week One: The defense played much better than expected. I'm still somewhat concerned about our zone coverage, but was pleasantly surprised by how Claiborne played in the running game.