PHILADELPHIA -- Gabe Kapler on Monday afternoon offered an interesting peek into a notable change the Phillies made to their offensive approach.

Stay on the fastball. Hit the fastball.

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The Phillies might have seen the early returns to that seemingly simple adjustment in a 13-7 victory over the Mets at Citizens Bank Park, which snapped their season-high seven-game losing streak. The Phillies had lost 10 games in the National League East standings during a recent 6-16 stretch, but they picked up a game against the Braves with the win.

“We know that hanging breaking balls, you don't have to sit on, you don't have to look for them or try to hit them. They sit up there, they spin,” Kapler said. “You can be on the fastball and blister a breaking ball. If you talk to our players or any players for that matter, they'll tell you the same.”

The Athletic wrote Monday that the Phillies have a lower slugging percentage against fastballs in the strike zone in 2019 (.489) and 2018 (.464) than 2017 (.505), when they lost 96 games. Their weighted on-base average on fastballs in the zone is lower in 2019 (.331) and was lower in 2018 (.318) than in 2017 (.342). Their wOBA on fastballs 94 mph or harder in the zone is lower in 2019 (.282) and 2018 (.314) than 2017 (.321).

It has been a major factor in the Phillies’ underachieving offense.

Kapler offered a reason why the Phillies might not have been hitting fastballs the past two seasons. They might have been looking for something else.

“One thing we've toyed with is thinking about looking for specific pitches in counts and I think there's some value to it,” he said. “But to simplify things right now, I think we get on the fastball, we stay on the fastball, we never come off it and we look to not miss our pitch.”

The Phillies were 9-for-15 (.600) against fastballs on Monday. Big hits included Bryce Harper’s run-scoring double in the second, Scott Kingery’s leadoff single in the fourth, Harper’s run-scoring double in the fourth, Maikel Franco’s two-run homer in the fifth and J.T. Realmuto’s one-out triple in the sixth.

The Phillies’ 13 runs in the series opener topped their offensive output in their previous five games.

“Sometimes you’re going to get the job done and sometimes you’re not,” Harper said. “Tonight, we were able to do that. We were able to get on [Mets left-hander Steven Matz’s] heater and hit some pitches out of the ballpark and score runs when we needed to and pick up [Zach] Eflin. We just did our job tonight. We know what kind of lineup we can be if we can do that and score some runs and stay positive and finish this half out.”

Had there been too much instruction, too much thinking before and during the Phillies’ plate appearances?

“The answer is we don't know,” Kapler said. “We are always trying to hit the sweet spot with our players. No two of them are built exactly alike, just like none of us in this room are built exactly alike. This is not rocket science. It's not some revelation someone came up with today to get on the fastball and stay on the fastball. This is something that most teams preach and something we've preached in the past. But it is a really good time to simplify a message for an entire group of hitters that we have historically done damage on that pitch and we will get back on track and begin to do damage on that pitch again.”

The Phillies had been searching for other ways to end their funk, too. They rolled out a pitching machine to spit out curveballs for an early batting-practice session. Realmuto, Andrew Knapp, Sean Rodriguez and Brad Miller participated. Miller even purchased a bamboo plant to put in his locker because he hoped it would bring the team good luck.

Maybe it all worked. Maybe it was coincidence. The next three games against the Mets, who are battling more off-the-field issues than anybody, will crystalize that picture. But the Phillies needed this win on Monday.

“It’s been frustrating. It’s been tough,” Segura said. “When you’re losing games, it’s no fun. When you’re winning, it’s fun.”

“We executed on our game plan to keep things light today and to come in with a little swagger,” Kapler said. “Sometimes the swagger pregame leads to a swagger in game. I think we got some of that back tonight and I think we’re on the right track.”