It takes a long time for defensive players to get up to speed in Belichick's system.
It seems to me that it often takes awhile for NFL players to "get" the Pats defensive systems, too, not just college prospects.
By my count, in the 2017 secondary, there were 4 players in their 1st or 2nd season in the system who contributed snaps:
- Gilmore, 1st year, 816 snaps (77%)
- Bademosi, 1st year, 214 snaps (20%)
- Rowe, 2nd year, 259 snaps (25%)
... missed seven games each year
- J. Jones, 2nd year, 439 snaps (41%)
.... also only his 2nd year in the NFL
In the 2017 front-7, there were 11 players in their 1st or 2nd year who contributed snaps:
Van Noy, *2nd year, 710 snaps (67%)
... *was actually only with the Pats for half the season in 2016
Roberts, 2nd year, 558 snaps (53%)
... only 2nd year in the NFL, too
Guy, 1st year, 582 snaps (55%)
Wise, ROOKIE, 543 snaps (51%)
A. Butler, ROOKIE, 473 snaps (45%)
M. Flowers, 1st year, 283 snaps (27%)
... had played only 72 defensive snaps in his entire previous career
Lee, 1st year 281 snaps (27%)
... ZERO previous NFL playing experience on defense
Marsh, 1st year, 266 snaps (25%)
Plus Harris, Harrison, RJF and Reilly.
Not surprising that it took awhile to "gel". Also not particularly surprising (or shouldn't be) that it failed in the SB against a very well-coached offense.
Anyway, when I'm thinking about "rebuilding the defense in 2018", I'm reminded that there was
already significant roster turnover in 2017, but also significant experience gained in the system to build on for 2018.