NFL

New corner helping Giants’ D focus on ‘ball or nothing’

Talk about your middle-school shenanigans. Notebooks, papers, pens, even drinks. If it was in your hands it was fair game as you walked through the halls. It all got slapped at and, without a firm grip — Wham! — there it goes, all spilled out onto the floor.

“Not open container drinks but like Gatorade,’’ Zack Bowman clarified.

It is not yet a way of life around the Giants as it was with the Bears, but Bowman is trying to inject the lessons he learned in Chicago into his new team, trying to instill that uncanny knack for getting your hand on the football and stripping it out of the grasp of the opponent.

“Knack? I think it’s more of like a mentality, you have to want to do it,’’ Bowman recently told The Post. “Once you have the will to want to do it then it’s a habit.’’

Line up Perry Fewell and the other 31 NFL defensive coordinators and every one of them will insist they preach turnovers and ripping the ball loose. But some teams and certain players are always better at it than others. The Giants last season weren’t bad at it. Their 29 takeaways (17 interceptions, 12 fumble recoveries) tied them with four other teams for the eighth-highest total in the league. The Bears in the past decade have been masters of the takeaway, though, and Bowman wants to take it to the next level with the Giants.

“We took pride in that,’’ Bowman said. “We had a grading scale that if you didn’t do it, it got marked against you. You got Charles [Peanut] Tilliman who is one of the all-time greats in forcing fumbles as a cornerback. Having the opportunity to play with him, learning from him, seeing the things he’s doing, one of the first things I asked myself is ‘Why not me? How come I can’t go out there and do the same things he’s doing?’ ’’

Bowman is one of the under-the-radar additions the Giants hope pans out for them. After six years with the Bears he signed a one-year contract for a base salary of $730,000, a cornerback added to a free-agent haul that already includes Dominique Rodgers-Cromartie and Walter Thurmond III.

Bowman, 29, will be used in certain defensive packages and is a big corner, big enough at 6-foot-1 and 196 pounds to serve as a linebacker in passing situations. He also immediately becomes one of the core players on special teams, where he is exceptional.

In training camp, Bowman seemed to get his hands on nearly every pass, knocking it away, deflecting it, grabbing it. He led the Giants with two interceptions in the preseason and had one called back by a penalty. He started only 23 games in six years with the Bears yet has 10 career interceptions. He also has two fumble returns for touchdowns on special teams.

“I used to play receiver back in the day, believe it or not,’’ said Bowman, who is from South Carolina and played in college at Nebraska. “Once you drop too many balls you’re the defensive back.’’

Giants defenders dispossess Steelers QB Martavis Bryant.Paul J. Bereswill/NY Post

In Chicago, Bowman said Lovie Smith and defensive coordinator Rod Marinelli stressed and taught ball-stripping techniques while linebacker Brian Urlacher, always seated in the first row in the meeting room, would not allow anyone to walk by without taking a swipe at their belongings.

“It just kind of carried over,’’ Bowman said. “Guys are walking down the hallway, they got stuff in their arms and guys would walk up behind them and hit it out of their arms. It was habit.’’

The main goal, Bowman said, was not to get a “loaf’’ marked on your sheet, a demerit handed out if the coaching staff deemed you were not running hard to the ball, not hustling.

“You won’t see any loafs on my paper,’’ Bowman said. “If you don’t see me running there’s something wrong.’’

The Giants have noticed.

“That was pointed out here by Perry as soon as [Bowman] got here,’’ defensive end Mathias Kiwanuka said. “He follows through at the end of every play with the intent to get the ball out. It’s something we should probably all pick his brain because you call it knack, you call it effort, whatever it is he just does it. That’s one of those things you got to tip your hat to because the guy, he’s focused.

“You see it out here, when you see someone do it over and over you think ‘OK, that’s something I got to add to my game.’ ’’