It seems to me that the balance of "positional importance" in NFL secondaries in general, and especially with the Pats, has been gradually shifting from CB to Safety as "nickel packages" have now more or less become the default defensive alignment. The Pats even played a 4-safety "dime" almost the entire time in the SB (which is a big part of the "football reason" that Butler didn't see the field, whether folks want to accept that or not).
I think this is all in response to the uptick in the numbers of mobile QBs, plus the increase in the popularity of RPO-type offensive play packages, plus the need to reduce defensive substitutions in the face of the no-huddle and hurry up.
So, the value of a DB who can man-up on a slot WR, as well as on RBs and TEs, plus play the run well enough to be the second LB (effectively) in 4-2-5 alignments has increased tremendously.
The Pats currently have two guys who can handle this (or have): Chung, primarily, and McCourty (at least to a greater degree in 2017 than in the past). Both turn 31 this coming August. Harmon has handled this role some in the past, too, so it's interesting that he appeared to be used more this season as the deep centerfielder, sorta swapping roles with McCourty.
And then there's Richards. Yeah, he's been pretty terrible. That he's the current backup and "dime safety" is unfortunate, but perhaps also an indication of how difficult it may be to find someone who can master this role. However, Richards now has three seasons of experience in the Pats system and has become a key special-teamer (being inserted as the personal protector on the punt unit in Ebner's absence is not insignificant). Plus, until a clear upgrade is actually under contract, Richards is all they have (and he's still relatively cheap).
The "experience" aspect is also not insignificant, in terms of how the Pats may address the position/role this season. It allows the Pats more latitude to try college prospects, perhaps even with an early draft pick. The alternative would be to try to find an affordable NFL player who's covered a similar role elsewhere. Such a guy would still lack experience in the Pats specific system and schemes, however. There would still be a significant learning curve.
Also currently on the roster, the Pats have (former UDFAs) Travis and Jones on future contracts off the P-squad. They've already experienced the transition from college life to NFL life and apparently performed well on the scout team all season. They'll very likely be in the mix this off-season and Camp, with a slight advantage over any rookies, at least at the beginning.
One outside possibility is Bademosi, if he's re-signed. Sure, he pretty much sucked in the safety role in the SB, when he was inserted for Chung temporarily on an emergency basis. However, he has decent size (6006/200+) and athleticism, he's a great tackler on ST, and he performed very well in coverage at CB for two games when both Rowe and Gilmore were injured (and it's notable that opposing QBs continued to pick on Butler instead of Bademosi and Jon Jones in those games). If he's re-signed, it certainly wouldn't hurt to invest in training him as another ST/backup for this role.
Obviously, another alternative would be to seek that (almost mythical) "coverage LB" who also plays the run very well, and is big enough to adequately stuff A and B gaps, as well as to set the edge when necessary. It seems to me that the Pats may be somewhat more likely to pursue both a coverage LB and a Safety upgrade this off-season than in the past.
Meanwhile, at CB, the Pats have:
... Gilmore
... Rowe
... Jon Jones
... Cy Jones (IR, ACL)
and Ryan Lewis, Jomal Wiltz from the P-squad.
Aside from Gilmore, there's not a whole lot of NFL experience in this group. So, the Pats may be more inclined to go with an NFL free agent than a draftee to backfill at CB. Still, I'm doubtful that they'll "go big" or make a trade unless they're significantly concerned about the development/availability of both Rowe and Jon Jones.
