But to execute all of this within a 40-second time frame is no small feat. The chain of communication is wrought with potential breakdowns — from Josh McDaniels speaking with coaches in the press box, to McDaniels calling the play into Brady, to Brady communicating effectively to his 10 teammates in the huddle, to Brady setting the blocking scheme at the line of scrimmage, to receivers going in motion, to all 10 players hearing any audibles from Brady, and finally to everyone hearing the proper snap count.

HOUSTON — It always looks simple enough. The Patriots huddle up, Tom Brady calls a play, the players align themselves into a formation, Brady barks out a few calls, then he takes a snap and hands the ball off to LeGarrette Blount or completes a pass to Julian Edelman.


“Communication goes on throughout the whole game — personnel groups, play calls, on the ball,” Edelman said. “You have to be able to communicate in a split second at all times. That’s what practice is for, and that’s what we try to prepare for in practice.”

RELATED: Interactive graphic: 40 frantic seconds

We spoke at length with McDaniels and other members of the Patriots to get a feel for how much goes into one simple play call:

■ 40 seconds on the play clock

The players pick themselves off the ground from the previous play and head back to the huddle.

Per NFL rules, McDaniels, the offensive coordinator, is the only person allowed to directly speak to Brady in his headset, and Brady is the only offensive player allowed to have a radio in his helmet. As many as three quarterbacks on game day can have an active radio in their helmets. For players who play both quarterback and another position, they must have two different helmets.


While only McDaniels can speak directly to Brady, all of the offensive coaches (plus head coach Bill Belichick, of course) are on the same frequency. And they are constantly communicating with McDaniels throughout each play.

When the play clock hits 40, the three coaches in the press box get to work. Director of personnel Nick Caserio is the most indispensable.

“Nick Caserio’s been talking to me for the better part of 10 years,” McDaniels said. “He tells me where the ball’s at, what hash it’s on, what’s the down and distance. He’ll say, ‘Left hash, second and 7 at the 33.’ Then sometimes I’ll call the personnel, then he’ll say, ‘Hey, they subbed nickel in.’ He’ll continue to communicate with me until the end.”

Assistant quarterbacks coach Jerry Schuplinski and coaching assistant Nick Caley are also charting the Patriots’ plays, the opponents’ plays, and constantly relaying information to McDaniels through Caserio.

“The other guys are charting different things, keeping tabs on the defense, charting our stuff offensively what we’ve done, a lot of different things that they take care of,” McDaniels said. “And then Nick’s the one that’s doing most of the communication.”

Once in a while, the coaches talk over each other. But the more they practice the communication, the more they know when and when not to speak.

“There’s a little bit of that,” said McDaniels. “Most of the time we try to avoid it.”

The Patriots have a system of hand signals in case the headsets don’t work, but they don’t use them often.


“Maybe [to indicate] some personnel, but not a lot,” McDaniels said.

■ 35 seconds on the play clock

After the players have huddled, McDaniels presses the button on his hip and starts communicating with Brady. It takes about 3-5 seconds to communicate a play call, and that includes letting Brady know which players are coming into the game and which players need to hit the sideline. The Patriots will be penalized if they ever have more than 11 players in the huddle.

“Some of that is signaled from the sideline, but there’s always a line of communication where I’m telling him what’s happening, so that he’s aware of the substitution and he can help facilitate that whole thing,” McDaniels said.

The players entering the game don’t know the play that’s about to be called. Often times the Patriots call two plays, giving Brady the freedom to choose one at the line based on the defensive look.

“Nobody knows the play except Tom,” McDaniels said. “I hit the button, tell him what’s coming in terms of personnel, then I’ll tell him the play, then he’ll call the play. It’s a process.”

■ 25 seconds on the clock

The Patriots break the huddle and approach the line of scrimmage. McDaniels continues communicating with Brady — perhaps the defense has just substituted in an extra cornerback, or watch out for the A-gap blitz.

“It’s not an every-play thing, but there’s definitely some times where I can say, ‘Heads up for this, they sub this in, whatever it is,’ ” McDaniels said. “Those never hurt.”


■ 20 seconds on the clock

Brady starts to assess the defense and make his calls. The most important call Brady makes is something fans hear on every play — which player (identified by number) is “the Mike!”

On some teams, the center makes that call. The Patriots entrust Brady with this responsibility.

What does it mean to identify the “Mike”? Brady is reading the defense to find the “Mike,” or middle linebacker, and it instantly sets the protection for the five offensive linemen.

McDaniels and the linemen were a little guarded about how they go about identifying their assignments. But in general terms, left guard Joe Thuney knows that he’ll have the player to the left of the Mike. Right guard Shaq Mason knows that he has the player to the right. And so on.

“Every play, you’ve got to have a pattern of blocking, certain guys blocking certain people, so we’ve got to get that organized,” McDaniels said. “It starts with somebody being the Mike linebacker, and then everything else plays off of that. There’s a lot of communication that will take place after that up front, that generally sets the protection, and they go from there.”

■ 15 seconds on the clock

Per NFL rules, McDaniels’s communication with Brady shuts off once the play clock strikes 15. The box on McDaniels’s hip buzzes, and the line goes dead. (If Brady snaps the ball with more than 15 seconds remaining, McDaniels’s headset goes dead at the snap.)


Brady continues reading the defense and making more calls.

He’ll send a receiver in motion, often to determine whether the defense is in zone or man coverage. If a defender runs with the receiver, it’s man. If the defense simply slides and adjusts, it’s most likely zone.

Or he’ll see a one-on-one matchup he likes — say, Chris Hogan on a certain cornerback — and motion Edelman away from Hogan’s matchup to open up that side of the field. Or he’ll motion Edelman to the edge of the offensive line to crack-block a defensive end on a running play.

When Brady feels confident that he has checked into the right play, and has the matchups he wants, and the protection is set, he’ll finally say, “Hike.”

Obviously, this process does not come together overnight. The Patriots work on their communication from the first day of spring practices in April.

“All day, every day,” McDaniels said.

On the defensive side

Communicating on the defensive side of the ball is a bit different. There is less huddling and no audibling, and crowd noise can play a factor when the Patriots are playing at Gillette Stadium. Hand signals are key, both from defensive coordinator Matt Patricia on the sideline and among the players on the field.

“You would think it would be easy for Matt P to call in a play and for you to just say it and that’s it,” said linebacker Dont’a Hightower, the Patriots’ primary defensive signal-caller. “But it takes time in practice.

“I had a lot of that in 2013. I feel like that’s what really helped me and pushed me in this direction. It’s something that [Elandon Roberts], he had to get used to Matty P talking to him in his head while he’s getting ready to play.”

On defense, teams are allowed to designate two players per game with communication helmets, identified by a green dot on the back. Hightower has it when he’s on the field, Kyle Van Noy has been the backup recently, and Roberts and Shea McClellin have handled it as well.

The green dot on the helmet — in this case Dont’a Hightower’s — indicates the player authorized to communicate electronically with the sideline. Getty file

“We kind of feed off each other, and had to get used to Dont’a’s Southern drawl,” quipped cornerback Logan Ryan. “Once we got used to that, it flows pretty smoothly. He’s not as bad as Van Noy. I hope he doesn’t have the green dot.”

The primary and the backup each have two helmets ready for the game — one with the headset and one without.

The backup must report to the umpire when he enters the game with a headset helmet. If both players are out of the game, no one on the field may wear a headset and the Patriots must communicate through hand signals.

“The communication at times is a little bit challenging if the green dot is on one guy and he’s not in there, then it falls to somebody else,” said Belichick. “They do a good job of that. Our safeties do a good job with that communication as well, so we’ve been able to handle it.

“But it’s a little bit of a challenge when the same person is not in there for every single snap as far as that part of it goes.”

While Brady is the only communicator on offense, it’s more of a collaborative effort on defense, with safeties Devin McCourty and Patrick Chung playing a key role.

“We’re all in on it, especially as the game gets going and we’ve got corners chasing good receivers all around the field,” McCourty said. “Sometimes they don’t make it all the way back into the huddle, so sometimes I’m deep and Chung is there and Chung turns and gives me the call and I get it out to the other guys.

“As safeties, we’re always responsible for everybody getting in the back end. We try to do that to take some of the pressure off High [Hightower] — taking care of all the guys whether it’s four or five of us in secondary at a time, and let High worry about the guys in front of him.”

“It all gets spread inside-out,” Ryan added. “We’re going to get it from Dont’a, and he’s going to spread it to the safeties, and they’ll spread it out maybe to me and I’ll spread it to the corners in a hurry-up situation.”

Three months after subtracting Jamie Collins and giving Van Noy, McClellin, and Roberts more playing time, the Patriots feel their defensive communication is flowing well.

“It’s a lot better,” Hightower said. “I think guys have gotten comfortable. I think we’ve kind of got that chemistry kind of built.

“There have been times now that me and KV [Van Noy] can kind of just look at each other and we kind of know what to expect, what we’re thinking.

“Whenever you get that, you can play a lot faster and kind of anticipate things. I think we’re finally at that point.”

RELATED: Interactive graphic: 40 frantic seconds

Ben Volin can be reached at ben.volin@globe.com. Follow him on Twitter @BenVolin