There are times when a contemporary coaching guru will swipe through an iPad containing his boundless digital playbook, craft the ideal game plan and make the perfect call at the precisely the right time.

“As a coach, you think you’ve invented something,” Vikings offensive coordinator Pat Shurmur said. “But I have this old Paul Brown playbook I got when I coached the Browns. It’s 2, 3 inches thick from the 1940s or ’50s. You think you’ve done something unique and then you look in that playbook and see the same play handwritten by a player copying what Paul wrote on a chalkboard.”

Same game, but different in so many ways.

On Sunday, the Rams (7-2) and Vikings (7-2) — old rivals who decided two NFC title games in the muddy snow of Met Stadium four decades ago — will fight for playoff positioning when they meet on plastic grass under a windowed roof at U.S. Bank Stadium.

Both teams are top 10 in scoring and points allowed. They’re prime examples of a faster, more wide-open game directed by coaching staffs that number into the 20s rather than the six who coached the Vikings during Bud Grant’s era.

Heck, even some of the age-old phrases are outdated.

“Back in the day, if you cut a guy, it was, ‘Bring your playbook,’ ” Redskins coach Jay Gruden said. “Now, it’s, ‘Bring your iPad.’ We don’t even give out playbooks anymore.”

Grant still has an office at Winter Park and has witnessed the technological evolution of the NFL “playbook.” At 90, he admits he doesn’t grasp it all but said he wouldn’t have objected to iPad technology half a century ago.

“It looks to me like it might be a lot easier,” he said.

What a mouthful

As a West Coast disciple, Shurmur has reached into his playbook and had his quarterback make this particular 14-word play call:

“Red Left Switch Tight Close Z Right, Sprint Right G, U Corner Halfback Flat,” Shurmur said. “The words ‘Red Left Switch Tight Close Z Right’ is the formation and motion. ‘Sprint Right G’ is the name of the protection. ‘U Corner Halfback Flat’ is the route concept.”

“Then it got even longer,” said Jon Gruden, Super Bowl-winning coach, “Monday Night Football” analyst and fellow West Coast guy.

“We started killing plays in the huddle against certain looks. The quarterback would say all that and then something like, ‘Orbit to Trips Right, let’s go 97 Wanda Zoro Kill it with 358 Cannon.’ ”

Even some West Coast loyalists realized that was too much verbiage.

“Now, that call could just be, ‘Sprint Right G Star,’ ” Shurmur said. “Players today are coming out of college learning how to communicate with fewer words. Plus, coordinators now want to affect the game with tempo. And if you want to push the throttle, you have to cut the verbiage.”

Meanwhile, spread across the kitchen table at Jerry Burns’ home in Eden Prairie this week were stacks of handwritten notes and plays from when Burns was Grant’s offensive coordinator in four Super Bowls.

There are calls as concise as “2 Sucker Screen Left” and “Statue Liberty Right” and “Purple 771.”

“Burnsie is the master of this stuff,” Grant said. “When I got the job in Winnipeg [in 1957], I already knew Burnsie [who was at Iowa]. I decided I wanted every player to have his own playbook. Burnsie came up and formulated my first playbook. He knew his stuff and he could write legibly.”

Handwriting skills aren’t exactly a high priority anymore. In today’s Vikings locker room, 13-year veteran guard Joe Berger is considered old-school because he can remember when coaches gave players DVDs of games to take home.

“He said you’d have to go through the game to find the plays you needed to watch,” backup guard Jeremiah Sirles said.

Today, NFL teams have digital staffs that break down every play, store it and make it instantly available for every situational query a coach or player will type on his iPad.

“Back in the day of reel-to-reel film, they might have tried to splice the tape,” Shurmur said. “But there was only one copy. A third down in the red zone, do you put that in the third-down cut-up or the red-zone cut-up?”

Those days are unfathomable to today’s players.

“The last paper playbook I saw was my junior year at Nebraska,” said Sirles, a four-year veteran. “Now, at the swipe of your finger on the screen, you can see what the play looks like in X’s and O’s, then videos of how it looked against an over look, an under look, how it worked against every kind of defense.

“You get a clear look at it and then you go out and rep it in practice. It’s pretty cool.”

Grant’s first playbook

Grant enlisted in the Navy right out of Superior (Wis.) Central High in 1945. He was assigned to Great Lakes Naval Training Station in Illinois, where he played football for Brown.

“That was the first time I ever saw a playbook,” Grant said. “I was pretty impressed by Paul’s organization.”

Grant went from there to the University of Minnesota and on to the Philadelphia Eagles as a first-round draft pick.

The Eagles started 2-0 in 1951 when coach Bo McMillin had surgery for an ulcer. Stomach cancer was found, ending McMillin’s coaching career and thrusting Wayne Millner to head coach. He went 2-8.

“The players didn’t have a playbook,” Grant said. “The coach had one folded up and in his back pocket. After [McMillin] was gone, we’d be practicing and you’d ask a question about how to run the play. The coach would have to reach into his back pocket, unfold the playbook and look it up.”

Historians believe playbooks didn’t exist in the league’s early days, when passing was rudimentary at best for most teams.

“Back then, you basically had four plays,” said Joe Horrigan, executive director of the Pro Football Hall of Fame. “You had four backs lined up in a T formation. Defenses basically just had to guess which of the four would run the ball in what was a straight-ahead power game.”

A pivotal moment in the evolution of the playbook came on Dec. 8, 1940, when the Bears and Redskins met in the NFL Championship Game in Washington, D.C.

That season, Chicago’s George Halas was using the T-formation with a man in motion, essentially creating the flanker position and confusing defenses with more of a finesse attack.

Redskins owner George Preston Marshall mocked the Bears’ style. The Bears won 72-0 while completing seven of nine passes.

“As the game evolved,” said Horrigan, “the offensive playbook had to evolve. And the defensive playbook followed.”

Vikings coach Mike Zimmer has seen the playbooks evolve into a constant back and forth as offenses and defenses take turns being the cat and the mouse.

“More so in today’s NFL, it’s how can you pressure, how can you take advantage of weaknesses, how can you disguise your coverages,” Zimmer said. “Back in the day, when I first started, teams pretty much always played what they normally played. Today, there’s a lot more disguise, a lot more trickery, I guess.”

Computer age

Jon Gruden believes he was the first quality-control coach in league history.

“It’s 1990 and I get hired by the 49ers,” Gruden said. “I’m the first guy I know of that made the playbook in computers. [Offensive coordinator] Mike Holmgren hired me and gave me a summer project while he went on vacation. He said, ‘Learn how to use this Macintosh SuperPaint 1.0 and we’re going to start our game plans on a weekly basis with your drawings.’ ”

With the ability to cut and paste on the computer, Gruden could adjust the plays to match all the different formations, motions and personnel groupings that flowed from Holmgren’s imagination.

“Five, six months later, I got ‘2 Jet Flanker Drive’ in my computer drawn 32 different ways just by cutting and pasting,” Gruden said. “Mike would do his corrections and add coaching points that I’d have to fix. I’d be in there all day and night. That’s why coaching’s not for everybody, bro.”

Erin Burns, Jerry’s daughter, remembers when her father always seemed to be doodling on whatever scrap piece of paper he could find.

“We’d be at a restaurant waiting for our food, and Dad would get a thought, grab the placemat and start scribbling,” Erin said. “I think I knew all the X’s and O’s by the time I was 5.”

Burnsie said things “were always popping into his head.”

“You’d grab something, write it down and the next day you either liked it or sometimes realized why it wouldn’t work,” he said. “You can’t be changing things all over the place. You want to be organized in your playbook.”

Doing so certainly has changed over the years.

“It’s amazing,” Erin Burns said. “My dad wouldn’t even know how to turn a computer on.”