Cornerbacks:
JON JONES - He's no Logan Ryan, but he's been pretty good.
... As the "new guy" last season, he was targeted on 11.6% of his snaps. At roughly the same total snaps this season (428 v. 439 in 2017), he's being targeted on 8.9%, roughly the same rate as JMac (8.7%) and Gilmore (8.6%). [JC Jackson, as this year's "new guy", has been targeted on 11.8% of his 110 snaps.]
... Jones' catch rate allowed is up a bit (53% v. 49%), YPC is the same (13.2), flags/tgt up (5.3% v. 3.9%). His "breakup rate" (INT+PBU/tgt) is slightly down (18.4% v. 19.6%), but his tackles/snaps is up (8.9% v. 8.2%). His TDs/tgt is way up (7.9% v. 3.9%), but he's allowed only one big scoring play (Westbrook, WK-2, 61 yds off a pick play).
... He's also effectively tied for 4th most-used guy on ST with Grigsby (avg 16.2 ST snaps/game).
... He's also credited with a couple of pressures and a run stuff, plus drawn a HOLD on the pass rush.
... He's RFA in 2019, so there's certainly no reason to let him walk.
JMAC - Quietly pretty good as starting LCB, essentially replacing Butler.
... He's been targeted slightly less (8.7% of snaps v. 8.9% for Butler), while allowing a 50% catch rate (Butler was 51% in 2017), and only 2.1% TD/tgt (v. Butler's 7.6%).
... He's had a similar "breakup rate" so far (16.7% v. 16.3% for Butler), a higher YPC (15.8 v. 13.7 for Butler), but hasn't been flagged yet (Butler's 2017 rate was 4.3% of tgts).
... JMac' tackles per snap has been good (7.2% v 5.8% for Butler), and he has contributed 95 ST snaps, while Butler contributed 0 last season.
GILMORE - Generally excellent until the Titans game. By far, the best RCB the Pats have had in a long time - maybe ever.
... His tgt rate is up a bit over last season (8.6% v. 8.3%), but his catch rate allowed is way better (40% v. 54%). His YPC is better (12.1 v. 14.2). His TD rate is slightly worse (5.2% v. 4.4%). His breakup rate is also way better (22.4% v. 13.2%), and his "flagged rate" is a bit better (6.9% of tgts v. 7.4%) in spite of the Titans game.
... Gilmore's tackles/snap is down (4.9% v. 6.1%), but he also has a sack and 2 FFs.
JC JACKSON - If not for being flagged 3 times (23% of his tgts), his numbers would be pretty good, for a rookie, and an upgrade over Rowe so far.
... Jackson has been targeted on 11.8% of his 110 snaps (v. 8.1% of 136 snaps for Rowe). He's allowed a 46% catch rate on 13 tgts (Rowe was 64% on 11 tgts), and a YPC of 14.7 (Rowe was 15.1). Jackson has also allowed 0 TDs, while Rowe allowed 2. Jackson has at least "dabbled" with ST (5-10 snaps/game), whereas Rowe played only 13 total ST snaps since the start of 2017.
... It seems unlikely to me that Jackson will be able to boot JMAC out of a starting role this season, but it may be a different story by the beginning of next season.
DAWSON - I haven't seen enough of Dawson at an NFL level to pigeonhole him as a "slot CB" or a boundary corner - or even as a pure CB at all. However many snaps he gets the rest of this season, I wouldn't be surprised if he gets at least a taste of pretty much every role in the secondary. Where he fits best in the secondary probably won't be known until next season (all of which is assuming that he's actually any good at the NFL level at any position).
Overall, I'd say that Cornerback is in pretty good shape as a group with one elite boundary guy starting, one solid veteran boundary guy (placeholder) starting, a good slot starter, and two promising rookies. They haven't been anywhere near "lockdown", and have given up too many splash plays, IMHO. But, they've allowed only 7 of 21 passing TDs and have 5 of the Pats 11 INTs (8th in the league).
