Infield coach explains why Phillies are confident in run-prevention strategy | Scott Lauber

Last Sunday, after giving up four singles in a row as part of a five-run sixth inning in a 6-1 loss at San Francisco, veteran pitcher Jake Arrieta leveled a scathing critique of the way the Phillies position their infielders. He accused them of employing the least effective defensive shift of any team in baseball and demanded both accountability and change.

Jose David Flores was neither offended nor overly moved.

As the Phillies' infield coach, Flores is responsible for breaking down data on opposing hitters, recognizing their tendencies, and implementing strategy based on the situation in the game. Glance at the dugout when the Phillies are in the field, and you will often see Flores moving his arms like a conductor to let the infielders know where to stand.

Flores didn't need Arrieta to let him know the Phillies have been shift-challenged. He concedes they had trouble in April, in part because the information they were using wasn't always up to date. But the Phillies were already making adjustments that Flores and manager Gabe Kapler insist have produced positive change and will continue to do so long after Arrieta's rant is forgotten.

"Things are said at times without knowing what actually is accurate," Flores said the other day in a wide-ranging interview. "Jake, I understand his point, and he's got a legit point of view. With that being said, we are going to continue to position our infielders how we think is going to be the best way to win a ballgame."

But that doesn't mean Arrieta is wrong.

At a time when non-traditional defensive alignments are all the rage across baseball, the Phillies are among the shiftiest teams. Through Thursday, they had shuffled their defense on 27.9 percent of plate appearances, the highest rate in the National League and fourth highest overall. They're particularly active against lefthanded batters, employing a shift 44.8 percent of the time.

"There are times we are aggressive. There are times that we are not as aggressive. There are times that we're aggressive according to a situation of the game," Flores said. "At times, we do it to get in the hitter's head. Maybe he likes to try and beat the shift and go the other way or try to bunt like [Cubs slugger] Kyle Schwarber did [Tuesday night] on a 2-0 count. If we accomplish that goal, then it was successful."

And that's fine as long as it works. But according to Sports Info Solutions, a service that has tracked and analyzed data on shifts since 2010, the Phillies are last in the majors by a wide margin in terms of runs saved by the shift, with a minus-9 rating entering the weekend. For context, the Tampa Bay Rays had a majors-best plus-17 rating. Almost every team was in positive territory.

Flores explained that the Phillies' analytics staff draws conclusions about a hitter's tendencies based on a breakdown of his most recent 125 at-bats, which are continuously updated in the team's internal network. In April, they were using at-bats from last season, and Flores said some of that outdated data was recorded manually rather than via TrackMan, the pitch-tracking system used by most teams.

"It was not as accurate as what the radar is showing as far as exactly where the ball was hit and so forth," Flores said. "We didn't have a lot of data during the month of April. Now we have more accurate data and that's why now, all of a sudden, you see better shifts and better positioning."

Relatively speaking, at least. The shift cost the Phillies eight runs through 26 games in April and 12 through May 25, according to Sports Info Solutions. Since then, though, they have saved three runs with the shift. Last Sunday, when Arrieta popped off, they actually held the Giants to one hit and turned a double play on seven grounders into the shift.

It's more than just more accurate data. Kapler said the Phillies have changed their shift based on watching their defenders. For instance, they noticed rookie Scott Kingery has better range to his left when he's playing shortstop. As a result, he has been shaded closer to third base to prevent more balls from getting through the left side of the infield.

One thing the Phillies aren't likely to do is change the frequency of their shifting based on the pitcher. Kapler said the team will seek more input from pitchers about various defensive alignments. But just because Arrieta uses his sinker to put the ball on the ground 56.3 percent of the time compared with, say, Zach Eflin's 32 percent ground ball rate doesn't mean the Phillies will shift less during Arrieta's starts.

"If you hit the ball on the ground to the left side of the field, it doesn't matter if it's [finesse Cubs starter] Kyle Hendricks or Eflin on the mound," Flores said. "You're still going to hit a ground ball to the left side of the field the majority of the time."

Flores said the Phillies didn't consider scaling back their shifting when it wasn't working in April. Instead, they worked harder to improve their data. And they will keep refining their process after Arrieta and his teammates are entirely satisfied.

"Can we make adjustments on the run depending on the results we're seeing? Of course," Flores said. "We want to get better. There's always room to get better."