A new Washington batter was introduced Wednesday night at Citizens Bank Park and the three Phillies outfielders instantly reached into the back pocket of their uniform pants.

They weren't looking for sunflower seeds or bubble gum. They were looking for directions.

All season, Phillies outfielders have played with sheets in their pocket that tell them where to stand for each opposing batter. Leftfielder Rhys Hoskins opened his sheet, moved a few steps toward center field, and tucked it away. Centerfielder Roman Quinn glanced at his sheet and walked to his right. Jose Bautista, in the outfield for the first time with the Phillies, paused and counted off his steps.

Each step a player takes originates from data collected by a computer model designed by the Phillies. Bautista reached his spot in right field, and the team's new outfielder was ready. Welcome to Philadelphia.

The Phillies have employed more defensive shifts this season than ever before. They have already shifted more this season than in the last two seasons combined. The shift — which some fear has been the great demise of baseball over the last decade — finally reached Philadelphia this summer thanks to manager Gabe Kapler and his cast of analytically inclined coaches.

"It feels new, and I understand why it feels new," Kapler said. "But every organization does it one way or another. At this point if you positioned your defenders in their 'normal spots' with the knowledge that it's not as likely that it's going to be hit in their normal spot, why? Like, what are you doing? "

It feels new because the Phillies were one of baseball's slowest franchises to embrace sabermetrics before they shifted gears over the last few seasons. That led to this season, when the team leaned on the numbers more than ever before. The fielders move so frequently that it feels rare to see them standing in their typical positions. There is a reason — and a number — behind every step.

How do the Phillies decide who moves where? A reader submitted this question as part of Curious Philly — an online space where you tell us what you want to know — so we found out.

Gathering the information

The Phillies began to embrace analytics in October 2015, when the team hired Dartmouth graduate Matt Klentak to be the general manager. A month later, they launched their own proprietary information system, aptly named PHIL. They built a research and development department and filled it with Ivy League-educated analysts who had worked for companies such as YouTube, Bank of America, and defense company Northrop Grumman.

Last October, the Phillies hired Kapler, who worked in the front office of the cutting-edge Dodgers after a 12-year major-league career. As a player, Kapler embraced analytics before they became widely accepted in major-league clubhouses. Now, the old-school Phillies weren't so old-school anymore.

The team's R & D department created a computer model that uses a range of factors to determine where a fielder should be positioned for each batter. The model accounts for a batter's tendencies, his success against certain pitches, and if the pitcher is righthanded or lefthanded. The model predicts the result of an at-bat, placing a dot where the fielder should be positioned if he hopes to catch the ball.

Sam Fuld officially retired last November after eight seasons as a defensive whiz in major-league outfields. He has an economics degree from Stanford and, like Kapler, always felt drawn to the numbers. He seemed perfect to fill the role of the Phillies' first-ever player information coordinator. His baseball background, combined with his Stanford education, allows him to be an ideal bridge between the players and the people in the research and development department.

A few days before the start of each series, Fuld spends two or three hours reviewing the information from the computer model, which outlines how many steps the fielder should take for each batter. Fuld watches video and combs through data to determine the accuracy of the computer's suggestion.

"It's essentially putting a bit of a human spin on what our R&D group does," Fuld said.

In the beginning, the model was new and imperfect, and corrections were substantial — Fuld often had to change the computer's determination by 10 steps. But the Phillies, Fuld said, have improved the model so much that now he feels comfortable correcting it by just two or three steps.

"We spend a lot of time looking at it," Fuld said. "Obviously, it matters to us. Personally, I know the importance of defense. That's how I had a career. This is something that's really, really important to me. But even if that wasn't the case, we all know the importance of defense and how far that can go to win games."

Using the computer's suggestion and his own outlook, Fuld finalizes the steps the outfielders should take for each batter. He lists each opposing batter on a sheet of paper with the corresponding steps — to the left, right, front, and back — next to their name. It's as easy to read as a lineup card. Those are distributed to the outfielders before each series.

"That's Part A," Fuld said. "And Part B is giving these guys the flexibility to do stuff on their own. There's a 30 mph gust of wind and everything is dying, you have the freedom — and we encourage them — to adjust.

"Whether it's wind, even something they see in a swing, or a guy is making an adjustment and they feel like, say, 'This guy is not seeing Nola's heater and he's going to be extra late on his heater,' then we encourage them to adjust. Part A is the suggestion in the card. Part B is allowing them to be flexible on their own."

Employing it in the game

Fuld is not in the dugout during games. He usually watches from the clubhouse or a front-office suite. Chris Young, the assistant pitching coach, oversees the outfielders' positioning. Young was previously the scouting director for the Houston Astros, who have employed more defensive shifts than any other team over the last three seasons.

Jose David Flores, the first-base coach, oversees the infielders' positioning. He follows a similar pre-series routine as Fuld, determining which opposing batters will see an infield shift and how dramatic it will be. He then presents the plan to the starting pitcher to make sure he is comfortable with how the defense will be aligned. The pitchers are then able to suggest a change based on how they plan to attack a hitter. The aim, Kapler said, is "to have our entire clubhouse confident on how our defenders are positioned."

The infielders do not have cards in their pockets, but instead have a meeting before the series to learn how they will shift.

"Usually, I'll just take a peek in the dugout and if Flo wants us to move over a couple steps, he'll move us from here and there," Scott Kingery said. "But for the most part, we know who we're shifting for. It definitely took a little bit of getting used to, but it was the plan from the beginning in spring training."

The repositioning of the fielders happens almost seamlessly; the players move during the dead time of the game. The outfielders check their sheets while the batter walks to the plate. The infielders move around the diamond before the batter even steps in the box. It happens fast. And if they need adjusting, the 6-foot-4 Young will wave his arms from the dugout to grab an outfielder's attention, or Flores will point to where the infielder should be.

Making revisions

After the game, the computer model that told the players where to stand publishes a "postmortem" for Kapler and his coaches to review. Instead of a dead body, this postmortem inspects the defense. It is a daily audit, determining if the Phillies installed the best practices.

The report, compiled by a member of the R&D department, displays the result of each at-bat. It outlines where the fielder was positioned and compares it with where the computer suggested he play and to where the coaching staff told him to play.

How does the computer model know where the player stood? A fielder's positioning is tracked by radar installed in 2015 in each ballpark by Major League Baseball. The radar's data are available to each team, and each team races to find ways to use it. The Phillies input it into their proprietary system, which digests the positioning information and publishes an easy-to-read report.

"What's cool is if you look at our actual positioning versus what the card said, we've actually done better," Fuld said. "Not only is what our card says doing better than traditional straight-up positioning, but on top of that, where they are actually standing is better than purely where the card told them.

"They're listening to their instincts. They're adjusting for the right reasons. They're looking at wind. They're putting themselves in a better position."

Do shifts work?

According to almost every metric available to the public, the Phillies have one of baseball's worst defenses. They lead the league in errors, have the worst fielding percentage, and are at the bottom of Total Zone Rating and Defensive Runs Saved, two popular advanced stats used to judge defense.

There is much uncertainty in baseball about the validity of public defensive stats. Teams shift much more frequently and much more differently than they did when those stats were established, so it's hard to see if the measures are valid.

"I think there's still a lot of unknowns," Kapler said. "We do the best we can with the information that we have. But we have all of this public-facing defensive-metric type stuff … and our own internal tracking, and none of it feels especially conclusive to us.

"We think there's a lot of flawed data out there. But we are doing our own work on it, and this is Year 1 of the way we're doing it. When we're down the road, we're going to be stronger and better at it. But I don't think we're ever going to completely agree with the public-facing data. Good or bad. It's not like RBIs, where he has 50 RBIs [means] he has 50 RBIs. Everyone is still learning."

On the flip side, the Phillies have allowed fewer runs per game than the league average. The front office often talks about "run prevention." It starts with a solid pitching staff, of course, but must also factor in fielders behind those pitchers. The Phillies are using the numbers to place those fielders where they think the ball will go.

The Phillies' infield shift has struggled because there is less margin for error when you move three infielders onto one side of the diamond. It has proved more difficult to perfect than the outfield. According to FanGraphs, the Phillies' infield shift has allowed the 10th-highest batting average and 11th-highest on-base percentage this season.

The Phillies defense has been a problem. The shift has not been perfect. Could stopping it fix their defense?

"We have considered shifting not at all, we have considered shifting less, and we have considered shifting more," Kapler said. "What we've come to believe, as of right now, we are shifting correctly. That's based not just on my own personal research, or the research done in the clubhouse, but many in the organization spending countless hours cross-checking what we're doing. We want people to call us out. We want the organization to work as a team to find ways that we can be better at positioning our defenders."

It is harder to measure the success of the outfield alignments, but the positioning has not caused many noticeable miscues since early in the season. A bad route taken by an outfielder or a poor read on a fly ball are separate issues. There have been plays this season in which an outfielder checks his sheet and then finds himself in the right position to make what could have been a difficult catch appear routine. The Phillies are clinging to those types of victories.

"It feels good. How can it not? I put a lot of work into it and take a lot of pride in it," Fuld said. "It hurts a lot when it goes the other way. It's hard to know if the pain outweighs the happiness when we are in the right spot.

"It's a lot like gambling. That's why I stay out of the casinos. The pain of losing is too much to enjoy the joy of winning. It's a little bit like that in the outfield. But I try to remind myself that there have been lots of good moments out there."