Football is a live-action version of chess, of course, and disguising your plays and keeping your opponent guessing is the foundation of the sport.

Game plans and special plays are protected like nuclear codes, and ­every offensive coordinator in the NFL covers his mouth with his play sheet when calling a game, in case the other sideline happens to have lip readers.

But you don’t have to have insider knowledge to be able to guess what’s going to happen on the field. Rob Gronkowski, believe it or not, gives away what’s about to take place.

When you watch the Patriots, or any other NFL game, take special note of the tight end before the snap. Where is he aligned? Which player is covering him? When he goes in motion, is anyone following him?

The tight end position, more than any other player on the field, is the “tell.’’

If Gronkowski is split out wide but being covered by a cornerback, the defense is probably in zone. If Gronk­owski is covered by a linebacker or safety, the defense is in man coverage.

If Gronkowski goes in motion and his defender follows him across the formation, the defense is in man. If he goes in motion and the defense simply shifts or rotates, then they’re in zone coverage.

Identifying those nuances is half the battle for any quarterback, and is part of what makes Tom Brady an all-time great. Brady is able to move his pieces around until he has a full read on the defense, then adjust his receivers accordingly.

Identifying those nuances is especially important for Jimmy Garoppolo, who is nascent in his NFL education and doesn’t have a wealth of experience to rely on like Brady does. And Garoppolo has a good sidekick in Gronk (or in last week’s case, Martellus Bennett).

“Gronk’s a great indicator for the quarterback, especially when you’re playing against a team that does a lot of multiple things on defense,’’ former Patriots executive Michael Lombardi said recently on WEEI.

Lombardi uses the example of Gronkowski’s 22-yard touchdown catch against the Seahawks in Super Bowl XLIX. The Patriots split Gronkowski to the right side by himself, and he was followed out there by linebacker K.J. Wright, who is not exactly known for his coverage skills. Brady identified the man-to-man coverage, saw the obvious mismatch of Wright on Gronkowski, and connected on a fade pass for a touchdown that almost seemed too easy.

“When Gronk lines up out there and K.J. Wright is with him, every quarterback in the world knows it’s man to man,’’ Lombardi said. “If there would’ve been a corner out there on him, then they would’ve known zone.’’

In the Patriots’ offense, the running back can sometimes be a “tell.’’ Usually it’s James White, who might go in mot­ion from the backfield to the slot, or vice versa. The defense’s adjustment to White’s motion often gives away its coverage. But on most plays the tight end is really the indicator, and has the toughest job and most responsibilities in the offense other than the quarterback, according to Bill Belichick.

“That’s the guy who does all the formationing,’’ Belichick explained in this week’s Sports Illustrated. “The running back is usually in the backfield. The receivers are receivers. But the tight ends could be in their tight end location, they could be in the backfield, they could be flexed. They could be in the wide position. To formation the defense, those are the guys you’re going to move. It’s moving the tight ends that changes the defensive deployment.’’

Former Patriots receiver Wes Welker said the Patriots will often approach the line of scrimmage with two passing plays — one for man coverage and one for zone. It’s then up to the quarterback to sniff it out.

“Whenever they put the running back outside, and they see a linebacker is on him, then they motion him inside, now it tells everybody, ‘OK, we have man to man coverage,’ ’’ Welker said on Friday. “Now you see the quarterback, ‘Alert! Alert!’ They have two plays at the line of scrimmage — one against zone and they have one against man — and now they’re going to the man route, and it’s going to be the rub, pick-type deals, to really help those guys get open where they’re not running a zone route against man. They’ve really evolved that offense to where, pick your poison on what you want to do.’’

And we saw Garoppolo do just that last Sunday night against the Cardinals. He noticed rookie cornerback Brandon Williams playing press-man coverage on Chris Hogan with no safety help over the top. Garoppolo screamed “Alert!’’, snapped it shortly thereafter, and calmly completed a 37-yard touchdown pass to a wide-open Hogan.

“Jimmy saw the single coverage out here, press coverage, so we ended up making a little adjustment to the play,’’ Belichick said on his weekly film review. “Great way to finish that first drive — not just on the long pass, but just the overall recognition and operation of the play.’’

LONG AND SHORT OF IT

Difference yet to show in kickoffs

The NFL competition committee voted to move touchbacks on kickoffs to the 25-yard line this season, with the hopes of encouraging more receiving teams to simply take a knee and reduce the number of kickoff returns. However, critics of the rule said the opposite would hold true — that the rule would actually increase the number of kickoff returns, with kickoff teams opting to kick the ball high and short and tackle the ball carrier inside the 25.

Let’s take a look at the numbers. In Week 1, the NFL saw 103 touchbacks on 165 kickoffs (62.4 percent). For the 2015 regular season, the touchback rate was 55.96 percent.

But wait! Anyone who follows the NFL knows that the ball is easier to kick in September than it is in November and December. We went back and looked at Week 1 of 2015, and the touchback rate was 66.9 percent (111 touchbacks in 166 kickoffs).

So for now, both sides are right — there were more touchbacks last week than there were on average during the 2015 season, but fewer in Week 1 this year than last year.

Count the Patriots as one team that is trying for returnable kickoffs. Last Sunday, four of Stephen Gostkowski’s six kickoffs were returned by the Cardinals, and he had a brilliant kickoff in the first quarter that was fielded in the front corner of the end zone and returned only to the 11-yard line.

“We’re going to make them earn however many yards they get,’’ Bill Belichick said last week. “We’re going to make them earn them. We’re not going to give them a quarter or 25 percent of the field. We’re going to make them earn every yard that they get the ball out to.’’

Several other kickers had the same philosophy. Sebastian Janikowski, who has perhaps the strongest leg in the league, had five of his seven kickoffs returned. Blair Walsh had five returns in seven kickoffs, Nick Novak had five returns in six kickoffs, and Connor Barth and Steven Hauschka had all three kickoffs returned.

But five kickers were content to boot the ball out of the end zone every time, including San Diego’s Josh Lambo, who had seven touchbacks.

ACCOUNTING DEPT.

Patriots’ cuts

A handful of notes about the Patriots’ roster and salary cap in light of the cuts from training camp:

■ Even with a 39-year-old quarterback, the Patriots are the eighth-youngest team in the NFL, with an average age of 25.68. The average team age is 26.11. The Ravens are the oldest (26.77) and the Browns are the youngest (25.06).

■ The Patriots are carrying about $13.7 million in dead salary cap money. Jerod Mayo accounts for the largest chunk ($4.4 million), followed by Dominique Easley ($2.9 million), Scott Chandler ($2 million), and Brandon LaFell ($1 million).

Among the noteworthy roster cuts: Running back Donald Brown counts for $336,240 in dead money, Terrance Knighton for $329,290, Keshawn Martin for $206,240, Josh Kline for $256,240, Aaron Dobson for $223,800, Markus Kuhn for $146,240, and Bryan Stork for $125,490.

■ The Patriots had to pay out injury settlements to players who got hurt in training camp. Defensive tackle Frank Kearse earned a $201,412 settlement, the equivalent of eight weeks pay. Linebacker Kevin Snyder earned $117,529 (six weeks pay) and running back Tyler Gaffney got $25,828 (one week pay). The players were released from the Patriots’ injured reserve but cannot sign with another team until after their settlement runs out.

Chandler is receiving $1 million in injury protection for the major knee injury he suffered last year. A player is eligible for up to 50 percent of his salary if he suffers an injury in a game or practice and then fails the preseason physical for the next season.

■ Rob Gronkowski and Nate Solder have financial reasons to get back into the lineup as soon as possible. Both missed out on a $31,250 roster bonus last week by sitting out the Arizona game with injuries.

■ Easley made the Rams’ 53-man roster, meaning the Patriots will get a salary cap credit in 2017 for every game Easley is with the Rams this season. Easley makes $35,294 per week, for a maximum of $600,000. If the Rams cut Easley after eight games, for example, the Patriots will get a cap cut of $282,352.

ETC.

Biggest loser? It’s not so bad

Rams coach Jeff Fisher has taken a beating for his team’s flat performance in a 28-0 loss to the 49ers and in the process passed Don Shula for the third-most regular-season losses in NFL history with 157. And Fisher might hold the ignominious title of the NFL’s biggest loser soon enough — he’s only eight behind Dan Reeves, whose 165 losses are the most in NFL history.

But appearing on this list isn’t so terrible. More than anything, it shows that Fisher has been good enough to coach long enough to compile enough losses. Tom Landry is No. 2 all time with 162 losses, and Tom Coughlin, George Halas, Chuck Noll, Chuck Knox, Mike Shanahan, and Curly Lambeau round out the top 10. However, Fisher’s .518 winning percentage is the lowest among the top 10, followed by Coughlin at .531.

Bill Belichick has a .665 career winning percentage and is 15th in losses with 113. Belichick has 224 regular-season wins, two behind Lambeau for fourth all time.

Extra points

Through the offseason, training camp, and Week 1 of the NFL season, 25 players have suffered torn ACLs, according to the Twitter account ACL Recovery Club. The list includes Chiefs pass rusher Justin Houston, former Patriots tight end Tim Wright, current Patriots tight end Mike Williams, Chargers receiver Keenan Allen, and of course, Vikings quarterback Teddy Bridgewater . . . Hard to feel sorry for a guy making $17 million this year, but it’s tough seeing Darrelle Revis get toasted for two weeks in a row, once on national TV. Might be time to move Revis to safety, like Rod Woodson and Charles Woodson before him . . . Six games last week were decided by 2 or fewer points, the most such games in any weekend in NFL history. Raiders-Saints, Bengals-Jets, Broncos-Panthers, and Giants-Cowboys were all decided by 1 point, and Patriots-Cardinals and Seahawks-Dolphins by 2 . . . Interesting to hear Brett Favre rave about the Patriots and call Jimmy Garoppolo’s performance against the Cardinals “outstanding’’ last week on SiriusXM NFL. Back in July, Jerry Glanville told us that Garoppolo reminded him a lot of Favre, in terms of his “fire’’ and “spirit inside of him.’’ Glanville drafted Favre for the Falcons in 1991 and coached Garoppolo at the East-West Shrine Game in 2014 . . . Drew Brees, who plays at the Giants on Sunday, is only 35 passing yards behind Dan Marino for third most in NFL history (61,361) . . . Josh Norman used to shadow Julio Jones, Odell Beckham Jr., and many No. 1 wide receivers last year in Carolina, so if Norman isn’t shadowing Antonio Brown, that’s on Washington defensive coordinator Joe Barry . . . Considering the Browns just lost Robert Griffin III for half the season to a shoulder injury, would they be so crazy to try to trade for Garoppolo after Tom Brady returns from suspension? The Browns studied Garoppolo intensely in the 2014 draft, and he had some big supporters inside the organization (owner Jimmy Haslam ordered the team to draft Johnny Manziel instead). The NFL trade deadline is Nov. 1 at 4 p.m. . . . Jeers to the NFL schedule makers for making the 49ers play a 1 p.m. East Coast game on Sunday against Carolina after playing a 10 p.m. Monday game last week. The Panthers will have nine days of rest while the 49ers have five days of rest plus a cross-country flight . . . Las Vegas got one step closer to landing the Raiders on Thursday when the Southern Nevada Tourism Infrastructure Committee voted unanimously to recommend raising the city’s hotel tax to raise $750 million for a 65,000-seat domed stadium to lure the Raiders. The NFL, the Raiders, and casino mogul Sheldon Adelson have proposed to pick up the other $1.1 billion or so in stadium costs. But the Raiders still have a long way to go before they can move to Las Vegas — the tax hike needs to be approved by the governor and state legislature, and a move from Oakland to Las Vegas has to be approved by at least 24 of 32 NFL owners . . . Tim Tebow told the Washington Post last week that concussions were one reason why he decided to pursue a baseball career instead of football. Tebow also said concussion concerns were why he never switched to fullback or tight end when he couldn’t cut it as an NFL quarterback. “I think there’s definitely a piece that, this is for real. Concussions are real,’’ he said. “One day, do I want to have grandkids and be able to hang with them and go play ball and play catch with them? Absolutely. So is that something that’s in the back of your mind? Yeah.’’

Ben Volin can be reached at ben.volin@globe.com. Follow him on Twitter @BenVolin, Material from interviews, wire services, other beat writers, and league and team sources was used in this report.