He liked the way the players competed and saw many of the techniques and fundamentals carry over from the practice field to the game. The rushing attack produced solid results. The defense held its ground. And the coverage teams played well.
All in all, not a bad start, even if Belichick put his trademark we-can-always-get-better tag along with the analysis.
Of all the encouraging signs, it was the performance of the new-look New England defense that had to have Belichick most pleased, or as pleased as a coach can be this early in the preseason.
For a short stretch at the start of the game, Belichick's defensive vision for the revamped unit came to life.
This is a faster, more athletic defense, the result of subtracting one 290- to 300-pound defensive lineman and replacing him with a player 30 to 40 pounds lighter who could be categorized as either a defensive end or an outside linebacker depending on how you view the scheme. Belichick said earlier in the year that NFL football is being played more in space, which puts a higher premium on players who can run, and that's partially why he's reduced the bulk this year.
Yes, the Patriots still have big bodies Vince Wilfork (6-foot-2, 325 pounds) and Kyle Love (6-1, 315) at the heart of things at defensive tackle. But the rest of the starting front seven Thursday was rounded out with ends/outside linebackers Chandler Jones (6-5, 260) and Rob Ninkovich (6-2, 260) and linebackers Dont'a Hightower (6-3, 270), Dane Fletcher (6-2, 245) and Jerod Mayo (6-1, 250).
Outside of Fletcher, who was subbing in for projected starter Brandon Spikes (6-2, 255), this is a likely facsimile of what can be expected when the Patriots open the season Sept. 9 in Tennessee.
It was a defense with a different look than what Saints quarterback Drew Brees remembers facing in past years.
"I remember when we played them in '09, we'd watch a game one week and it was 3-4, and then you'd turn on the film the next week and it's all 4-3. And so you're just sitting there going, 'How do they determine how they are going to play [and] when they are going to play it?'" Brees said, adding that it forced the Saints to prepare for both.
"Sure enough, in the game we did see a little bit of both, but it seemed like [Thursday night] they were a little more exclusively 4-3 from what we saw out there. I think a lot of that is based off of the personnel you have and how you are building your team."
Brees hit on one of Belichick's big offseason alterations on D and how the changing NFL game has seemingly altered his value of defensive personnel, thus leading to a different approach in how he's built the 2012 Patriots.
One might sum it up this way: Bigger isn't always better if it compromises your athleticism.
Last year, Belichick signed Shaun Ellis (6-5, 290) in free agency and projected him as a starter at left end. This year, Ninkovich is projected to start there, and what a difference between the two -- Ninkovich is a nonstop, high-motor guy.
As for the whole 4-3 versus 3-4 debate, Belichick's defenses will almost assuredly never do just one thing, so it's a safe bet to assume that the 3-4 will be mixed in at some point. By having five starters in the 250-to-270-pound range, there is built-in flexibility based on the versatility of those players.
But as Brees pointed out, in the early parts of Thursday's opener Belichick used mostly 4-3 and things couldn't have gone much better for the Patriots, the unit forcing back-to-back three-and-outs to open the game before Brees' night was over. This was the same New Orleans offense -- minus dangerous tight end Jimmy Graham, of course -- that marched 77 yards for a touchdown to open last Sunday's Pro Football Hall of Fame game against the Arizona Cardinals.
The Patriots' defense proved tough enough against the run (2 rushes, 7 yards) and athletic enough against the pass (1-of-4 for 4 yards), both in coverage and with the pass rush.
"I thought we played competitively against both the running and passing game," Belichick said after his film review.
Mayo, in particular, was one of the best defenders on the field. Yes, that was him running downfield with Saints receiver Lance Moore on the second play from scrimmage, forcing Brees to hold the ball longer than he wanted to and go through his progressions before ultimately firing an incomplete pass because the solid coverage allowed the energized rush a little extra time to slice through the pocket.
Belichick has said it for years -- a good defense is one that marries the coverage with the pass rush. Good coverage helps the pass rush. And in turn, an aggressive pass rush helps the coverage.
If the Patriots can play like they did Thursday, combining both elements, a defensive turnaround might be a realistic possibility for 2012.
It's a new look -- less bulk, more speed.
The opening act was encouraging.