Here's one of those things that I don't think I've pointed out enough - or clearly enough. That CK really has come a long way in his indentification of run alignments and fronts.

Here the Saints come out in a 4-3 under front with the "open" or "weak" side DE in a "wide 9" set. You've probably heard the term, "wide 9" talked about. It refers to the DE lining up, instead of the traditional "7" technique - outside shade of the TE, but widened out by an extra couple of feet into a "9" technique. But, since there's not double TE or, in the this case, TE, the wide set outside the EMLOS it's a "wide 9" set.
The numbers I've put on the pic refer to the "technique" or position each of the guys are aligned as.
A little football 101 - the 4-3 under is determined by the "3" technique moving to the weakside and the strong side DT in a 1 technique position with the "sam" or strong side OLB coming up over the TE. In this set, you'll also see the 2 LB's stacked over the Guards. The benefit of this formation is that it covers all the run gaps and prevents T/G combo blocks on a the strong side and makes it harder to pull a guard towards the strong side.
To combat this, CK could be heard on the broadcast make a call and motion Boldin in, what he does is, presumably, change the side the play is designed to go to.

Ck motions Boldin in to hold up the wide 9 technique. Boldin will end up blocking out on his man who followed him, but, he causes the EMLOS hold up just a bit to give Boone a great angle on the EMLOS.

Staley and Iupati get a devastating combo block on the "3" technique, and move the LOS.

You see the wall the O-line is creating and Boone is gonna get a good kickout block with McDonald leading up in the hole.

The lane opens up and McDonald has a good head of steam on a defender.

McDonald does good job of leading through and somehow Iupati blew his guy all the way upfield. Staley also did a good job of sealing off the interior defenders. We get a solid 11 yard gain on the play. That is run game beauty.
This is where Ck has made a lot of strides. It was one thing I noticed a lot when A. Smith was here, he did a great job of consistently getting us into good running looks and calls. Since CK has been here, haven't seen it as much called from the LOS. He's making good strides here to identify the alignment and adjusting the run call.