Who is more valuable: Earl Thomas or Richard Sherman?

In trying to think of something that would be unpopular with Seahawks Twitter, I succeeded:

Is this a blasphemous opinion? Let me go through the arguments for each before closing with a poll.

The Case for Earl Thomas

The case for Thomas is obvious after watching how the Seahawks performed without him after suffering a pair of injuries in 2016, the latter of which ended his season. Danny Kelly has done a great job showing both (a) how good Seattle was at defending passes to the deep middle before losing Thomas:

(b) and how badly they fell off after:

After Thomas went down, the Seahawks allowed several long touchdowns that likely would have been prevented if Thomas were in the game. The lack of Thomas didn’t manifest itself only in preventing deep passes to be completed, but also in preventing long yardage to be picked up after the catch. Here is a missed tackle by Steven Terrell resulting in a huge chunk of extra yards:

The Case for Richard Sherman

If the case for Thomas is so obvious, why are we even having this discussion? The Seattle defense fell apart without Thomas, so Thomas must be the more valuable player, right?

The problem with this line of argument is that we’ve never seen what the current iteration of the Seahawks looks like without Sherman. He was inserted into the starting lineup in 2011 and hasn’t missed a start since. How do we know that the defense wouldn’t fall off just as much without their elite cornerback?

We saw above that Thomas removes the deep middle of the field from an opponent’s passing attack. However, the same is true for wherever Sherman is playing:

Look at #1 on the list above. Fewer than half of passes thrown at Sherman have resulted in catches, with passes at Sherman resulting in 13 touchdowns and 32 interceptions. In the regular season, since 2012, Sherman has accounted for 26 of Seattle’s 85 interceptions (31%), compared to Thomas with 16 (19%). You can say that Sherman should be getting more interceptions than Thomas due to the positions they play, but that doesn’t make those interceptions any less valuable. And there’s still a massive dropoff in turnover generation from Sherman to the other top CBs listed above.

In addition, it is hard to know how valuable being able to shut down opponents’ star receivers. Here are some recent examples:

• Antonio Brown: 10 targets against Sherman: 3 catches, 24 yards, 2 interceptions (this counts an interception on a 2-point conversion attempt). This was right when Brown was tearing through the league. Look at how much of an outlier this game was for him (especially the yards per target column on the far right):

• Julio Jones: 5 targets against Sherman: 3 catches, 40 yards
• AJ Green: I can’t find the target numbers for this one, but after Green scorched Cary Williams on two straight plays, Sherman switched onto Green and Green was never heard from again

If Sherman were replaced with a cornerback who is about as good as Terrell, I’m not convinced that the Seahawks wouldn’t struggle just as badly. Having an elite cornerback is extremely valuable in the NFL, and no one is better than Sherman.

Please vote in the poll and then feel free to tell me how wrong I am in the comments section or on twitter @guga31bb. Since Thomas is younger and plays a position with a more forgiving age curve, he’s probably the right choice going into the future, so let’s assume we’re talking about value to the team from 2012 through 2016 only.