You look for cracks, even the tiniest ones you can find. Maybe a throw that doesn't come out of his hand quite as quickly or as accurately as before. Maybe something in his footwork that isn't quite as smooth or as precise as it once was. Maybe a certain situation that no longer is handled as perfectly as in one of those Super Bowl-winning/MVP seasons with the New England Patriots.
It isn't there.
When members of the Buffalo Bills' defense watch video of Tom Brady, they don't see the erosion one would expect from a 39-year-old athlete in his 17th NFL season. They see the same Tom Brady they've always seen. They see greatness. They see, according to informal polling of the Bills' dressing room, the best quarterback they've ever watched play the game.
"You are" looking for signs of decline "and you don't see it," said outside linebacker Lorenzo Alexander. "I think a lot of it is he doesn't take a beating, he doesn't take a lot of hits, so he's fresh. Peyton Manning was still a great quarterback (at 39 and in his final NFL season in Denver last year), but he had the neck injury, so his arm started to fade. Tom's arm isn't fading, so he's still able to make all the throws he was able to make when he was 25. But now he's smart. He has all that experience, so it's even harder to kind of game plan for him because he's seen everything."
"It seems like he's playing even better than he was in the past," defensive lineman Corbin Bryant said. "I call it wisdom. He's been in a lot of battles and it seems like he's getting smarter as the years go on."
This stat line pretty much says it all about where Brady is in the so-called twilight of his career: Three games, 101 attempts, 76 completions, 1,004 yards, 75.2 completion percentage, 9.94 yards per attempt, eight touchdowns, no interceptions, 132.6 passer rating.
After missing the first four games due to the #Deflategate suspension that he fiercely contested, he is playing with a clear, though unspoken, vengeance. And now the Buffalo Bills get their first crack at him of the season Sunday at New Era Field.
"He's done it before where he's missed a whole year with an injury and comes back and does the same thing he's doing now," Alexander said. "He still had training camp, still had offseason. He just missed the first four. And then he's getting right back in rhythm. He's been with those guys for so long, same scheme, so he's not really missing anything. Just insert him back in and it's, 'OK, this is how we're doing it,' and everybody jumps on board."
Brady was on the final game of his punishment when the Bills faced the Patriots on Oct. 2 in Foxborough, Mass. The 16-0 victory counts as much as any of the Bills' three other wins, but it does carry an asterisk. The losing quarterback was Jacoby Brissett, a third-string rookie making his second career start because of an injury to No. 2 quarterback Jimmy Garoppolo.
The Patriots' offense had some obvious limitations that day, with offensive coordinator Josh McDaniels having Brissett work with about half the field on pass plays and operate at a more methodical pace with greater protection in order to give him the best chance to succeed. The Bills' defense took full advantage of that.
Things will be very different Sunday.
"We know what we're going to get," coach Rex Ryan said. "I mean, we're assuming we're going to get way more what Brady does. They play more up-tempo, so you're going to get more no-huddle, you're going to get way more empty (backfield). So we've got to have a great plan for them and, hopefully, we can somehow keep them off-balance."
That didn't happen when the Bills faced the Patriots in the second game of the 2015 season. Brady threw for 466 yards and three touchdowns in a 40-32 victory. Although the Bills sacked him twice and hit him five times, he consistently frustrated their pass-rushers with his ultra-quick release.
Another problem for Buffalo's defense was that it made it too easy for Brady to make his pre-snap reads. "If he knows what you're in, you're in trouble," Ryan said. "I think, when he scorched us the first time, he knew exactly what we were in."
The game plan of simply matching up with receivers and winning one-on-one battles rather than trying to disguise coverages backfired.
"We knew we made a big mistake by doing that, by letting him know what coverage we were in and just forget it," defensive back Nickell Robey-Coleman said. "Like just play backyard football, whoever's open throw it to him. Nah, we can't do that. He complicated us, so we got to bring a little hell to him."
Said defensive lineman Kyle Williams, "We've got to be able to show different things and then play something different (than what he thinks he's seeing). It's kind of a cat-and-mouse game with him."
In the Nov. 23 rematch at Gillette Stadium, Brady threw for only 277 yards and one touchdown. The Patriots won, 20-13, but the Bills did a far better job of harassing the legend.
Despite sacking him only once, they hit him 10 times and repeatedly forced him to hurry throws. At one point, Monday Night Football cameras captured Brady having a meltdown on the sidelines.
"What do you do to a guy that's seen everything and he's already a Hall-of-Famer?" Alexander said. "The only way you can do it is by making him uncomfortable and making him human, and that's by getting to him with a four-man rush."
Alexander wasn't with the Bills last season, but that won't be the only difference Brady will see from their defensive front. As well as his scheme worked against Brady last November, Ryan knows that he had better make some alterations or his defense could be carved up as it was in last year's first game against the Patriots.
"You don't want to present the same picture, because once he's seen it, he's got great recall and he's got the skill to beat you," Ryan said. "Hopefully, you can paint a different picture."
The Bills have 21 sacks in seven games, as many as they had all last season. Alexander, who leads the NFL with nine sacks, gives their pass rush a new dimension and a perfect complement to fellow outside linebacker Jerry Hughes.
Defensive tackle Marcell Dareus is expected to play his first game of the season after a four-game suspension and three games nursing a hamstring injury. He should contribute to the Bills' ability to generate inside pressure, as well as helping the edge rushers have less blocking attention.
Dareus also should help the Bills do something that was a major fail in last week's loss at Miami: stopping the run. Buffalo's defenders still haven't rid themselves of the bitter taste of Jay Ajayi's 214 yards.
The Patriots have a top-notch back of their own in LeGarrette Blount, but when the teams last played, the Bills -- thanks largely to the 18 tackles of linebacker Zach Brown -- held him to 54 yards.
Job One Sunday is preventing Blount from having an Ajayi-like performance, because that, at least in theory, will help the defense turn up the heat on Brady.
"You've got to be a professional," Alexander said. "You've got to throw (the Miami game) out. It's like having a bad play. You can't continue to think about that bad play if you want to move onto the next one. So it's our jobs, as leaders in this locker room -- Kyle Williams, (Leger) Douzable, and myself -- to let guys know, 'Let's leave that where it was. Sunday, we're done with that, that wasn't us, let's move forward. But if you continue to think about it, you're about to walk into a buzz saw because we have a great team, probably the best team in the NFL right now, that's about to walk in.'
"So that's why we really didn't pay too much attention to that, because we don't really want to watch that game and allow it to linger into this week."
With the ageless wonder coming to town, the Bills don't really need anything else to think about.