Mark Weidemaier’s defensive positioning has been dictated in part by pitchers like Tanner Roark. (Photo by Mitchell Layton/Getty Images)

Under Manager Davey Johnson, the Nationals used defensive shifts less than any other team in baseball. When Matt Williams took the helm this winter, he vowed the Nationals would implement more data into the positioning of their fielders. He even brought a coach, Mark Weidemaier, with him from Arizona to serve as defensive coordinator.

And this season … the Nationals still rank among the least-shifting teams in baseball. It is by design, and recently it has worked – after bungling their way through April and the start of May, the Nationals have been among the best defensive in baseball for the past month.

The Nationals have been more active in positioning fielders than in years past. But rather than aggressive alignments popularized by the Pirates and Astros, among other teams, the Nationals favor more subtle positioning.

“A lot of people talk about the shift,” Weidemaier said. “[Forget] the shift. That’s extreme. We’re going to shade, whether it’s two or three steps, right or left. That’s the key. That’s the real key.

“A shift, that’s extreme. That’s when three infielders take one side. It’s for guys like Big Papi, Ryan Howard. That’s extreme. It’s positioning. We’re going to try to put them in an optimal spot to start, and then move from there according to the charts and research that we’ve done.”

The Nationals plan their defensive positioning from a different standpoint than shift-happy teams. The Pirates either target a certain style of pitcher or train their own to match their defense. Williams comes at it from a pitcher-first perspective. He wants the defense to bend to how the pitcher operates.

“Shifting is one thing,” Williams said. “But we take into account our pitchers and how they want to pitch, how they want to approach. We’re not going to shift just because. We take it to our pitching staff and say, ‘Here’s an option for us. We may want to shift this guy. What do you think?’ We take their input and their feedback and go according to them.”

Since he came off the disabled list, Doug Fister has been key in the Nationals’ defensive meetings. He attended them in San Diego last weekend even though he did not face the Padres.

“That process has shored itself up,” Williams said. “They’re taking more of a lead role in that, saying, ‘Here’s how I’m going to attack him. Here’s how we can play him.’ So we can adjust accordingly defensively. That creates a cohesive plan for everybody.

“We have some really good starting pitching. I, for one, want to play to their strengths. We’re going to try to play to their strengths. That’s the idea. It doesn’t work perfectly every day. But at least we have a cohesive plan going in. That gives us confidence going into a game that we’ll be in the right spot and he can make his pitch effectively.”

On May 12, the Nationals ranked last in the majors in’s defensive runs saved metric at -14. The Nationals have moved up to 12th overall, having now prevented eight runs with their defense overall, according to the formula. The Nationals are plus-22 this month; only four teams have saved more runs with their defense all season.

Along with a better understanding of how the Nationals use the shift, Nationals fielders have regressed to the mean and, simply, worked hard to fix a major flaw. The Nationals vowed they would improve, and they have. They haven’t made an error in a season-high five games.

“I think it was a little bit of an aberration,” Williams said. “There were some weird things. They work hard. I think they’re all comfortable and settled in. The first month and a half was rough. Since then, it’s been good. They’re concerned about it. They take pride in it.”

On most teams, Williams said, only reserves attend voluntarily infield practice on day games after night games. “Any time we’ve done it, generally the whole team has been out there,” Williams said. “That’s a pleasant surprise, and much appreciated.”

“We probably do more early work – groundballs, that type of thing – than any other team,” Weidemaier said. “It shows.”

Weidemaier said the Nationals have also improved in the way they go about pregame practice. They seem more focused to him and “not just mindlessly fielding,” Weidemaier said. He hits infielders groundballs to mimic each play they may see in the games – backhands, high-hoppers, etc.

Anthony “Rendon is phenomenal,” Weidemaier said. “I hit [bleeping] rockets to him.”

Lately, Nationals pitchers and fielders have been boosting one another. Pitchers have rarely walked hitters, which keeps the defense alert. Fielders have been turning more balls into outs, which gives pitchers more incentive to throw it over the plate and let batters put it in play.

“It’s a cumulative effect,” Weidemaier said. “We put the work in. We have our meetings, get guys in the right place.”