Obviously Jimmy Graham is a phenomenal talent but in figuring out how valuable he's going to be to the Seahawks this year we need to do some thinking about how he'll be used in the offense and how that matches up with his skillset.
I know some are concerned about the blocking, but I'm much less so--I figure he's going to be used in a lot of 12 or even 13 personnel where he's split wide as a 6'7" mismatch WR and Willson and/or McCoy are tight to the formation. He'll be useful to the run game even if he just runs decoy deep routes to occupy a couple DBs (and catch PA bombs if they cheat off him), but also this can manufacture lots of "easy" blocking opportunities for him where he's just enveloping a CB that he physically dwarfs or cracking back on an unaware LB, rather than ever asking him to stand up a strongside DE the way Miller did.
The bigger concern is that much of his passing game value in New Orleans has come from volume rather than rate stats. This past season in a down year (injury issues plus fall off for their offense as a whole), he was still 10th in DYAR (total value) for TEs but just 19th in DVOA (per play value) on 125 targets. 2013 he was 1st in DYAR but 12th in DVOA on 143 targets. 2012 he was 9th in DYAR and 23rd in DVOA on 135 targets. He's pretty much always been top-2 in TDs for TEs, but also always been top-2 in target volume.
It's not easy to find him 130+ targets on the Seahawks. If we look at pass-catchers as a whole the single-season target leader for the RW era is a tie between 2013 Tate and 2014 Baldwin with 98 each--for TEs it's 2013 Miller with 56, but I think it's fine to say Graham is our new #1 WR for the purposes of this calculation. So generally we've had one guy around 100 targets, one guy around 70, and a few others (including TEs and RBs) in the 40-50 range.
Would we be properly maximizing Graham's value if we just plugged him in for that #1 option's 100 targets, with Baldwin getting 70 and the rest scattered among Kearse/Willson/draft pick/Lynch/Richardson when healthy? If we take his 2013 (86/1215/16) as a best-case production scenario, but then prorate it to 100 targets (ignoring for the moment whether there's any efficiency/volume tradeoff), it's more like 60 catches for 800 yards and 10 TDs. If you think 2014 (85/889/10) is a reasonable floor and prorate it, you'd have 68/711/8.
The TDs still look great and obviously he can be a redzone weapon for us, but I think most would be disappointed if we traded Unger and a first for 60-odd catches and 700-800 yards (ie just duplicating what Baldwin puts up as a low-volume #1). So how could we find some more targets in this offense?
Option I: take them away from other pass targets? Probably not. Wilson's thrown the ball around 400 times a season since he's been here, so the #1's already getting a quarter of the looks. I don't think we want it to be a third of them, as part of the "point guard QB" ideal we've strived for is spreading the ball around and finding the open WR rather than forcing it to one guy and getting too predictable.
Option II: pass more at the expense of the run? I'm not sure this is where we want to look either. We just paid Marshawn a lot of money to come back (and want to find opportunities for Turbin and Michael as well), and the run is a key part of our identity and scheme (keeps us out of 3rd-and-longs, puts us in favorable field position, keeps the defense rested, sets up explosive plays via PA, etc.).
Option IIa: pass more at the expense of QB runs? This is more likely. Wilson had 118 carries last year (after 90+ his first two years) and we will probably want those to diminish over time. Plus if he has a big-bodied target in Graham that he can always find on scrambles, he won't have to run on so many of them. Side note: he also took 42 sacks last year, many when he couldn't find any open WRs. It'd be great if we could turn some of those into pass attempts as well by finding Graham as a hot route. If you could turn 40 runs + sacks into passes, that could be 10 or more extra targets for Graham.
Option III: run more total plays at same run/pass balance? This is ideal, at least depending on how we get there. One way is to convert more 3rd downs and stay on the field, which Graham could be great for. Last year in his down year he had still 54 first downs (61 the year before). The most for a Seahawks WR in Wilson's time here was Baldwin's 42 last year (most from a TE was Miller with 18). If he can extend a couple drives a game for us it's win-win-win (more targets for everyone, more carries for the run game, and more rest/better field position for the defense). The other way to get more snaps is to snap the ball faster--we've generally avoided the hurry up except when needed (since at least a slow three-and-out gets the defense a little more of a breather than a fast three-and-out...) but if we knew we were better about sustaining drives we might be able to safely play with a little more tempo (compounding the number of extra opportunities).
I still don't think there's any way Graham gets to that 140-150 target range he did in a couple of his Saints seasons, but if we can work RW's total number of pass attempts to 500+ by decreasing QB runs and sacks and by sustaining drives, there's a possibility of getting him to 120+ (this is all assuming he's the unquestioned #1 rather than a co-#1 with Baldwin or a further new acquisition), which probably puts him in line to produce something like his "bad" 2012/2014 Saints numbers: ~85/900+/10. That'd be the unquestioned best receiving season for a Seahawk since 2007 Bobby Engram.