Shootout expert T.J. Oshie says three-on-three in overtime could be ”a cool thing.” (John McDonnell/The Washington Post)

To Washington Capitals defenseman Matt Niskanen , it felt like a “summer shinny scrimmage,” six bodies swirling around with endless room for breakaways and unobstructed one-timers. This was the NHL’s new three-on-three overtime, and the organized chaos resembled that of a fire drill.

“That doesn’t feel like really hockey,” Niskanen said.

Opinions on the three-on-three overtime format are mixed. Skill forwards are expected to enjoy the increased space. Defensemen and goalies are not. The general consensus is that it’s a better way to resolve a game than a shootout, and with so much room on the ice, fewer games will need to be decided by one.

Every team will have three preseason games go to a five-minute, three-on-three overtime regardless of the score. Those games for the Capitals are the preseason opener vs. Carolina on Monday, then at Boston on Tuesday and against Boston again Oct. 2. Coach Barry Trotz plans to experiment with different strategies to find out what works best.

“We just want to have a plan, just like we do five-on-five or four-on-four,” Trotz said. “We’ve got to have a plan for that as well. We’re starting to build a framework, but we don’t have enough data to go, ‘This is what we want to do for sure.’ ”

The expected personnel are two forwards and one defensemen, though in a scrimmage Sunday, Washington experimented with two defensemen (Niskanen and Karl Alzner ) and a forward (Brooks Laich ) as a sort of prevent defense to a Russian trio, forwards Alex Ovechkin and Evgeny Kuznetsov and defenseman Dmitry Orlov. Sending out three forwards also is a possibility.

The Ovechkin, Kuznetsov and Orlov group appeared to be playing a man down at times in the defensive zone, with Ovechkin waiting for a breakaway by the offensive blue line. After trying a few “out of the box” things, Trotz said the Capitals would probably “tone it down” for preseason games.

The American Hockey League had a three-on-three element to its overtime. So at the start of training camp, one bit of advice Trotz got from the Hershey coaches was “you’re going to get a really good chance, and you better score on that chance because if you don’t score on that chance, you’re giving up a bigger chance the other way,” he said.

With the three-on-three format, the AHL had 75 percent of its games that went past regulation time decided in overtime this past season. The number was 35.3 percent in 2013-14, when it played a four-on-four overtime format.

Hershey Coach Troy Mann said there’s consideration for employing strategic bench positioning on line changes, putting the three players up next at the end of the bench closest to the defensive zone because teams will defend the goal farthest from their bench in overtime — a “long change.” Since it’s so fast-paced, shift lengths also are a concern. Mann said a shift over 45 seconds could lead to noticeable fatigue.

“It’s not meant for it to go on very long,” goalie Braden Holtby said.

The Capitals will have the advantage of having a goaltender who can handle the puck. Holtby’s ability to make a long pass to the red line or the far blue line will be a threat. Players also could pass it back to him to keep the possession alive, which also could buy time for a risk-free line change.

Winger Marcus Johansson said it’s “more hockey” to resolve a game in three-on-three rather than a shootout. Like Niskanen, center Nicklas Backstrom said it reminded him of pickup games he had played as a kid, but “then you only played three-on-three in one zone, so you’ve got some more space now.”

Ask new Capitals right winger T.J. Oshie what he thinks of the new format, and there’s an unexpected tinge of disappointment from a skilled forward who figures to thrive in that setting. Oshie’s most memorable feat was his shootout heroics against Russia in the 2014 Sochi Olympics, when he single-handedly lifted the American team to a win with four shootout strikes during the preliminary round.

Oshie said he doesn’t think many games will go to a shootout anymore, adding with a laugh that it’s “unfortunate.” But after three-on-three scrimmages Sunday, Oshie got his wish when the two teams practiced a shootout. He glided his stick from one side of the puck to the other, scoring effortlessly through the five hole.

“There’s some skilled players here, so I’m just going to try to scratch the lineup for the three-on-threes,” Oshie said. “I think it’ll be a cool thing.”