From Michael Holley's War Room, a quote on the draft by Bill Belichick.
>“The first-rounders are the guys, obviously, with the fewest questions. In the second round, a lot of times you find players with first-round talent but not first-round performance or production, if you will,” he says. “Then in the third round, you see guys who are maybe better football players than a lot of guys in the second round, but not as maybe overall talented, in terms of measurements. So I think there’s a certain bust factor, if you will, in the second round. That’s just in general.” (478)
The second round is when Belichick takes risks. Ignoring the last two drafts, because it's probably too early to evaluate those players, by my count the Patriots have hit on starting caliber players 10 out of 24 picks, a rate of 41.6%. That's pretty decent considering that the first round hit rate between picks 21 and 32 is about 47%. The draft is a bit of a crapshoot and even the best front offices get it wrong more than 50% of the time across all picks.
For what it's worth; War Room is a pretty good look at how Belichick (and his personnel tree) evaluate players and value their resources.