Bill Belichck has many credos. You don't hang around as long as he has, and seen as much success as he's seen, without establishing a few.

One of them stood out in the aftermath of Sunday's rollercoaster victory in Pittsburgh: Everything matters. Every play. Every. Little. Thing.

He alluded to that point after the game, referencing an important late-game kickoff that was lost in the madness of the final two minutes. He harped on football's butterfly effect -- how every play is a game-changing one -- again Monday morning.

"I think the message for us is just every play’s important and every situation’s important," he said. "You’ve just got to be prepared for all of them. You never know which ones are going to come up."

In this edition of the grades, we'll go out of our way to zero in on the little things. The minutia. The tackles. The blocks. The punts. The hand signals, even. Because they matter, however small. And when you stack them up, one on top of the next, you could end up with something significant. Something like home-field advantage throughout the playoffs, potentially.

Click through for this week's marks. 

The numbers won't jump off your screen -- 22-for-35 for 298 yards, a touchdown and an interception -- but Tom Brady was, in spurts, both elusive and accurate. The truly poor throws or decisions were minimal. He was nearly picked in the first quarter by TJ Watt on a receiver screen, but Brady knew he had a free play after Cam Heyward jumped offsides. His third-and-nine throw at the end of the third quarter fell incomplete when he was starting to feel the Steelers front breathing on him. He pumped when he didn't need to, he ignored a wide-open Phillip Dorsett, and he was drilled by Stephon Tuitt, leading to a punt. His first throw of the two-minute drill, the one that was nearly picked, was batted at the line. Not on him. Brady's interception was ugly. He should not have let that one go with Javon Hargrave bulldozing Shaq Mason into his lap. But the good far outweighed the bad. As a deep passer, Brady hit five of seven attempts for 148 yards, including a well-placed 43-yarder to Cooks on the first Patriots drive, and multiple clutch dimes to Rob Gronkowski in single coverage. The fourth-and-one slant to the big tight end was preceded by a little hand signal to Gronkowski, and it resulted in a big-time completion. The 50-50 (or was it 95-5?) throw dropped in over Gronkowski's shoulder in the second quarter was another money toss. And the quick-strike touchdown pass to Cooks featured one of the many important little things Brady did in this one, namely stepping up to avoid pressure, and making a perfect pass on the move. Can it be considered an on-the-run throw for someone who moves at Brady's speed? It was close, and it was one of his best moments on a night littered with pretty good ones. 

The Patriots averaged 4.6 yards per carry, picking up 79 yards and two scores on 17 carries. What Dion Lewis provided was particularly impressive, ripping off 5.2 yards per attempt and piling up 67 yards and a touchdown on the ground. The game-winning eight-yard score left him with two Steelers to beat (after Rob Gronkowski and Dwayne Allen wiped out their assignments). He slipped through one potential tackler and beat the other to the goal line. Rex Burkhead had more trouble finding space as he managed just 12 yards on four carries before leaving with a knee injury. His absence may force the Patriots to rely on Lewis more, something they've been reluctant to do in part because they want him fresh for the stretch run. James White, surprisingly, couldn't free himself against a Steeler defense that is downright poor at the linebacker spot. He seemed to suffer some kind of lower-body ailment early on but remained in the game. 

There were a handful of sneaky good plays from this group. But only a handful. Brandin Cooks' touchdown should only earn him continued trust from Tom Brady when the Patriots are near the goal line, because he -- wait for it -- did his job during a scramble drill, bailing out his quarterback by uncovering at the last possible second. His skill set isn't best used in tight like that, but that was one of his better plays of the night. We already know he can run by people, as he did in the first quarter to pick up 43 yards on a deep corner route, so the touchdown was a little change-up from the norm for him. Otherwise, this group was mostly quiet. Danny Amendola (two catches, 23 yards) came through with a quick whip route on a third-and-three to pick up a first down. Kenny Britt checked in with a catch on two snaps for seven yards, effectively not puking on his shoes in what was probably the biggest game of his professional career. The one obvious blemish from this position was the Cooks illegal touch. Brady dropped a pinpoint pass deep down the field to the burner, but he was pushed out, came back and caught it. Can't do it. In that situation, Cooks will probably be the first to tell you he has to do a better job of stacking his defender off the line to ensure that he won't be knocked into the sidelines. 

I can't recall a non-Tom Brady individual performance that was as dominant as Rob Gronkowski's at the end of this game. Yes, there have been plenty of games like the one James White had in Super Bowl LI, with next-level production. And there have been moments where one player's athleticism is simply too much. For instance, 2007 was peppered with Randy Moss takeovers. But rarely has one player so thoroughly dominated a game in so many facets. What Gronkowski did was Jordanesque. His 168 yards -- 69 of which came on the game-winning drive -- were a career-high and the third time he's broken the 160-yard mark in his career. He has the Steelers defense to thank, in part, for covering him with just one defender, usually safety Sean Davis. But that's the risk the Steelers ran. They wanted to play more man because Brady shreds their zones. They opted to use a deep safety -- sometimes over the top of Cooks and sometimes over the top of Gronkowski as a true safety valve -- as well as a "rat" player in the short-to-intermediate area. They had help floating around; itt was just rarely where it needed to be. Pittsburgh clearly would've been better served outright doubling Gronkowski from snap to snap and forcing Brady to go elsewhere. Gronkowski looks healthy, making catches on passes floated over his shoulders and fired at his ankles look as easy as the ones that hit him in the numbers. His quickness at the line beat Davis for a critical two-point play, and it beat corner Artie Burns on a slant for a critical fourth-down conversion. He dropped a would-be touchdown during the first drive of the second half. James Develin also had a drop. And Dwayne Allen had a false start penalty. But what Gronkowski was able to do -- and we haven't even mentioned the powerful block he put on Stephon Tuitt, working in conjunction with Dwayne Allen's pancake on Davis to pave the way for Dion Lewis' go-ahead score -- was enough to wipe away any of the negative plays this group submitted. Easy "A."
 

Another week, another test for the interior of the Patriots offensive line. Cam Heyward and Stephon Tuitt are arguably Pittsburgh's two best defenders, and they were a handful. Brady was pressured on 15 snaps, and that duo combined for 11 pressures on its own. Nate Solder was solid on the left edge (no sacks or hits), and his subtle signal to Joe Thuney with just under two minutes remaining allowed him to pick up a zone pressure, while Thuney stepped left and picked up Tuitt. Little things . . . On the opposite edge, despite allowing one of the team's two sacks, Cameron Fleming continued to hold his own on the right side in place of LaAdrian Waddle (13 snaps). Thuney, meanwhile, gave up a sack to Heyward, and he allowed Heyward to collapse the pocket when Brady's late fourth-quarter pass was tipped and nearly intercepted. Shaq Mason was the guilty party when Javon Hargrave pressured Brady into his fifth pick in four games, and Mason allowed Tuitt to get into the backfield and hit Brady on a tackle-end stunt. David Andrews was mostly stout, though it appeared as though the ground he lost to Heyward on a Dion Lewis run in the third quarter forced Lewis to do some dancing behind the line of scrimmage before he lost three yards.

The failed extra point could have been a crucial mistake by the Joe Cardona, Ryan Allen, Stephen Gostkowski operation, but there was more good than bad from this group as it came through with critical field-position plays in a game that came down to the final few yards. Trevor Reilly and Jacob Hollister got things going with sound kick coverage to open the game, giving the Steelers a long field and preventing any kind of momentum-building start. Ryan Allen's boot and Matthew Slater's sliding save (and delicate bat-back) pinned the Steelers inside their own territory at the end of the third quarter, helping lead to another long field and an eventual punt. Gostkowski's kickoffs were on point, including one that was tracked down at the 22-yard line by Nicholas Grigsby before Pittsburgh's final drive. Grigsby continues to show up on a weekly basis ever since being plucked off of the Ravens practice squad less than a month ago, and Belichick pointed out his tackle as a critical one after the game. His point? If the Steelers had much more yardage on that return, who knows if JuJu Smith-Schuster's long catch-and-run might've ended in the end zone? 

Though Le'Veon Bell came away with 117 yards on 24 carries, the porous nature of the Patriots run defense seemed to fall more on the shoulders of Patriots linebackers and defensive backs than it did on the big bodies up front. With Alan Branch out, Ricky Jean Francois saw some time and came up with a pair of run stuffs and drew a hold. Malcom Brown was in on a whopping six stops, and Lawrence Guy had a pair to go along with his sack. Eric Lee still had his issues on the edge in the run game, but he came up with a pair of near-sacks, and the Patriots pass rush got a big boost from the return of Trey Flowers. He had seven total quarterback hurries, meeting Deatrich Wise at the quarterback for a sack. Flowers was occasionally burned in coverage, used in that capacity because of missing pieces at the second level, but he gave the front some life. Wise, for his part, had was may have been his best game since September, coming up with the shared sack, another hit and a run-stuff. 

Let's start with the good. Le'Veon Bell was bottled up at the line of scrimmage late in the third quarter, strung his run out to the sideline, and was tracked down by a hustling Elandon Roberts, who finished with six tackles. David Harris made a strong on Bell earlier on the same drive. Otherwise, it was hard to find much positive. And given the ball control the Steelers exhibited, much of what they did in the run game seemed to fall on those manning the second level. There were missed gaps -- or gaps that were hit too aggressively against the ever-patient Bell, as seemed to be the case on Bell's third-quarter score -- that led to key gains. You could tell this group, still without Kyle Van Noy, might be in for a long day when on the first play from scrimmage Harris seemed to have Le'Veon Bell in man coverage and lost him for a 22-yard reception. Roberts was blocked easily on the next snap and Bell picked up five yards on the ground.

When it comes to the grades, critical plays in key moments will always carry more weight than plays at other points. That's why, despite helping allow the Steelers to convert on 10 of their first 13 third downs, this group's grade is where it is. The Eric Rowe deflection, coming moments after he was left with no one to cover (whether that was a hiccup on his part or not) on the Jesse James' non-touchdown, was monumental. As was Duron Harmon's pick, simple as it was. The tackling from this group late was mostly good, with the JuJu Smith-Schuster long catch-and-run being the obvious exception. Jordan Richards and Devin McCourty both could have attacked that one differently, stopping it before it became an emergency situation. But Harmon retreated quickly enough to catch Smith-Schuster before the goal line. And his tackle on third down on Pittsburgh's previous drive -- he picked up McCourty's communication just before the snap and crashed down to tackle Smith-Schuster out of a bunch look to force a punt -- was one of the more underrated plays of the game. Malcolm Butler submitted what may have been the most underrated play, tackling Darius Heyward-Bey in bounds and keeping the clock running as the Steelers scrambled to figure out what to do in the final seconds. His day became a little easier when Antonio Brown went down with an injury, but seemed to rebound from a tough outing in Miami in Week 14. Stephon Gilmore, meanwhile, took a step back. His breakup in the first quarter was nice, but he lost his leverage on Martavis Bryant and was overpowered at the end of the first half (and, yes, he got away with a push-off) to give up a touchdown. Gilmore had a run stuff on Pittsburgh's second-to-last drive, but the Steelers seemed to take advantage of him in the run game on sweeps. After seeing that on tape, it would come as little surprise if the Bills tested Gilmore as a force player this weekend.