For the Lake Braddock defense, positions exist, but they’re more fluid than on conventional football rosters. Defensive linemen look like beefed-up linebackers. Linebackers sometimes look like basketball players. And to an uninitiated onlooker, it might be difficult to tell which is which.

With many modern high school offenses operating out of the spread and often calling run-pass options, defenses are starting to catch up. To Bruins Coach Mike Dougherty, the antidote is using lighter athletes with increased speed and versatility on defense. He’s not alone.

To counteract the speedy, up-tempo offenses, many defenses have de-emphasized the need for hulking run-stoppers who clog up lanes and make plays with brute force. In their place are quicker, interchangeable athletes who can maneuver in space.

“Our guys are flying all over the field,” Dougherty said during the team’s first week of practice this month. “It’s scary and fun at the same time. I don’t want guys getting their heads torn off [this early in training camp], but it’s fun to watch.”

At Lake Braddock, a public school in Northern Virginia, Dougherty has noticed players becoming leaner and more toned because of a greater focus on training and conditioning. In addition, Lake Braddock is in a cycle in which the players have smaller frames rather than stocky builds.

So teams such as the Bruins are relying on players who can cut quickly and snatch the ball out of the air thanks to their length and agility — not only at defensive back, where those attributes have long been desired, but also at linebacker and defensive end.

At public schools, coaches often ask basketball players to become dual-sport athletes. Sometimes it works; sometimes it doesn’t.

“It is changing drastically. … The one thing that is kind of alarming is the basketball players not taking advantage of this,” Woodbridge assistant coach Gary Wortham Jr. said. “There needs to be a push.”

High school football in the Washington area is still adjusting to the influx of spread offenses. In states such as Texas, which has seen the spread incorporated over the past 10 to 15 years, defenses have had more time to tinker with the ideal system and become blueprints for other teams.

Cody Alexander, a defensive backs coach at Midlothian High in suburban Dallas, has written two books on defending modern offenses.

“Now the arms race is: ‘Can I get a kid that can play in space?’ ” he said, explaining the prevailing strategy. “It used to be that everyone kind of had a home … but now you are getting smaller so that you can compete with the space because obviously if you are faster you can cover more space and probably are a little bit more of a fluid athlete.”

From high school up to the NFL, offenses are frequently spreading the field with three-plus wide receivers to force defenses into mismatches. Those formations, which started at the college level, put stress on defenses to contain players the entire width of the field, and the evolution has made athletic linebackers and slot cornerbacks more valuable.

And high school players — particularly elite ones — are getting more comfortable in these types of situations because of the rise in popularity of seven-on-seven offseason football and passing camps.

“It has changed the game,” said Nick Codutti, offensive coordinator at Tomball High near Houston. “It’s become more of a basketball mentality of ‘I’m going to get my kids in space, I’m going to isolate you, and I hope your athletes are as good as mine.’ ”

That raises an obvious question: If defenses are going small, will offenses beef up again and pound them with the run?

Coaches are always thinking ahead, and some believe there will be a gradual shift in which some offenses flip back to a more traditional, run-heavy style.

“The reaction is always going to be: ‘Let’s get more speed on the field,’ ” said Alexander, the coach and author. “The offense is going to say, ‘How can I get you into a personnel package where you’ve got light guys and now I’ve got heavy guys and now I’m going to run the ball at you?’ It’s that constant cat and mouse.”

Of course, the way for a defense to have all the bases covered is to use players who can do a bit of everything.

In the D.C. area, two of the top players in the 2020 recruiting class are versatile linebackers: Woodbridge’s Antoine Sampah, who committed to LSU, and Mekhail Sherman of St. John’s, who committed to Georgia. Both have the ability to drop back in coverage or stay in the box and defend the run, making them attractive prospects.

Sampah, 6-foot-2 and 220 pounds, thrives in tackling in the open field. The first six plays of his freshman highlight tape were all jet sweeps he stopped from his middle linebacker position. It prompted North Carolina to give him his first Division I scholarship offer.

As much as Sampah is a modern-day player, other recruits are of the same mold.

“The other linebackers that were offered all together when they went on these college visits, [they] all looked like Antoine or taller and leaner,” said Wortham, who noted that Woodbridge’s defensive philosophy is to use fast, lean players. “It was incredible. … This is now becoming the trend.”

Having to contend with potent passing attacks, defenses in college are moving toward base packages that include additional players in the secondary, a trend that has trickled down to high school.

The Big 12 Conference — with defenses looking for answers to stop the league’s prolific offenses — is a laboratory for innovation. Iowa State’s use of three high safeties and Texas’s middle safety defensive look have made their way into high school playbooks. Each scheme relies on an extra defensive back who has more linebacker-type responsibilities, adding another layer of speed and agility to the defense.

Coaches such as Dougherty are watching and thinking of ways to try to make lives miserable for the quarterbacks on Lake Braddock’s schedule.

“Totally different sport," he said, “than I think it was 25 years ago.”

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