On Sunday, the Washington Nationals became the first team to clinch a division title in 2017. The Nats, currently 20 games up on second-place Miami, led the division nearly wire-to-wire, but it hasn’t been as easy a journey as the standings made it look.

Any Nationals title challenge would have to be built on great seasons from Max Scherzer, Stephen Strasburg, Gio González, Bryce Harper, Anthony Rendon, and Daniel Murphy—and that’s been the case in 2017, when those players have been healthy. But GM Mike Rizzo and manager Dusty Baker have had to rebuild the team’s complementary pieces continuously and on the fly.

This year’s Nationals recall the famous paradox, the Ship of Theseus: If you took a ship and replaced each plank of wood one by one, how much could change before the ship was no longer the same thing it started out as. The answer: more than you’d think.

At the All-Star break, the Nationals bullpen was a shambles: 29th in baseball in ERA-, 25th in win probability added, and tied for sixth in blown saves with 14. After letting closer Mark Melancon walk in the offseason, Washington had planned on using a Blake Treinen–Koda Glover–Shawn Kelley troika in the late innings, but by the break, all three had an ERA above 5.00, as did free-agent pickup Joe Blanton, who’d posted a 2.65 ERA in 156 innings over the previous two seasons. The only Nationals reliever with an ERA below 3.00 was journeyman Matt Albers, a dad-like 34-year-old Texan who, entering this season, had spread a career 6.2 K/9 and 97 ERA+ across 604 big league innings in 11 seasons for six teams.

Kelley has a 7.99 ERA thanks to 12 home runs allowed in 23.2 innings. Glover is likely out for the year with back and shoulder injuries. And Treinen lost his job in the second week of the season, running his ERA up to 5.73 by the time he was traded to Oakland in July.

A good bullpen can’t make a bad team good, but for a good team, a bad bullpen can be a death sentence. A couple of blown saves can be the difference between finishing out of the playoffs at 90 wins or in the playoffs at 92, or—as Washington has found out in its two five-game LDS losses and one four-game LDS loss since 2012—the difference between winning and losing a playoff series.

So on July 16, Rizzo traded Treinen and two prospects to Oakland for Sean Doolittle and Ryan Madson, then picked up Twins closer Brandon Kintzler at the trade deadline. In two weeks, Rizzo had acquired three 30-somethings with significant closing experience. Doolittle and Kintzler are both All-Stars, and Madson has two 30-save seasons under his belt, plus two World Series rings for his work as a setup man in Philadelphia and Kansas City.

None of them knew what they were getting into.

“You just saw whatever was on the highlights,” Kintzler said. “I knew Albers was having a great year, maybe they just had some blowups at the wrong time.”

Doolittle, playing in the other league and on the other coast, learned that he was supposed to save the season when he faced the Washington media for the first time.

“Every question that I got was something about the way the bullpen had been performing up to that point,” Doolittle said. “That’s why I’m glad I came over with Madson and I’m glad we added Kintzler, because so often it’s the case when you make a midseason acquisition that the expectations that get placed on that guy are a little far-fetched or unfair. Since there’s three of us, we can all shoulder that and work off each other and help each other out.”

Kintzler also appreciates having two other veteran closers to lean on, even if only one of them can pitch the ninth at a time.

“I think when there’s just one guy, you’re supposed to be the savior, but they brought three of us over and put us in roles right away,” Kintzler said. “It took a couple times in the seventh inning for me to settle down—obviously throwing in the ninth for a few years, it’s a bit different.”

Coming over with Madson also helped Doolittle—who’d spent a decade in the Oakland organization—acclimate to a new clubhouse. Doolittle played with Ryan Zimmerman at the University of Virginia, played on Team USA in 2005 with Scherzer and catcher Matt Wieters, and spent some time with González in the A’s farm system, but apart from those relationships from the distant past, he was entering a locker room full of unfamiliar faces.

“The analogy I’d use is it’s like switching schools in the middle of the year,” Doolittle said. “You want to earn the trust and respect of your teammates but at the same time, when we came over here, this team was solidly in first place. There were a lot of things going right—you don’t want to come in and change the vibe of the clubhouse. In the first couple weeks, you lay low and figure out where you fit in.”

Doolittle’s fit in as Washington’s closer, and since the trade, he’s appeared in 24 of the Nationals’ 51 games—all wins, with 24 strikeouts and a 200 ERA+ in 24 innings. He’s perfect in 17 save opportunities. Madson, who missed time with a sprained finger on his throwing hand, is 3-0 since he joined the Nationals. Kintzler is 2-0 with a 184 ERA+ in 18.1 innings since the trade.

Since the break, Washington’s bullpen is tied for eighth in ERA-, and has a win probability added of 4.75, the best in baseball over that time. The Nats relievers’ collective second-half WPA leads second-place Baltimore by more than the Orioles lead 18th-place Pittsburgh. That guarantees nothing for the playoffs, but the Nationals bullpen is pretty good for now, thanks to three players who weren’t in the organization two months ago.

Washington’s big offseason acquisition, Adam Eaton, tore his ACL back in April stepping on first base. Three and a half months later, Bryce Harper hyperextended his knee on a similar play. Shoulder and toe injuries have limited Jayson Werth to 55 games, which means the Nationals have been without their entire starting outfield at times down the stretch. In mid-August, backup outfielder Brian Goodwin, who’s posted a 105 OPS+ in 278 PA, went down with a groin strain and still hasn’t come back, while shortstop Trea Turner, who finished second in Rookie of the Year voting last year while playing mostly center field, missed 51 games with a broken wrist.

“Injuries are gonna happen,” said Howie Kendrick, who came over from the Phillies in a July 28 trade. “There’s obviously a few key guys—Werth, Harper, Scherzer—but when those guys come back, that just makes our team that much better. For any winning team, you’re going to have to have guys step in.”

For nine years, Kendrick was the starting second baseman for the Los Angeles Angels, and one of the game’s more underrated players. In 1,081 games with the Angels he hit .292/.332/.424, giving him the 37th-highest WAR total among MLB position players over those years, but for all his consistency, Kendrick earned only one All-Star invitation and three points’ worth of MVP votes. In 2015, he moved up the freeway to the Dodgers, where he held down second base for four months before losing his position to Chase Utley. Since then, Kendrick’s reinvented himself as a utility player, playing five different positions, plus DH, since the start of the 2016 season. This year, Kendrick’s hitting .332/.385/.500 in 288 PA, including a .322/.371/.554 line since the trade from Philly.

Kendrick’s started 23 games in left field for Washington, essentially making him Werth’s replacement, and despite having no explanation for why he’s having a career year at age 34, Kendrick is out-hitting Werth by 167 points of OPS.

“Same game, same stuff, just different environment,” Kendrick said. “I just prepare the same way and do the same things every year. Whether you have more success or less success, you can’t foresee that stuff.”

While the Nationals had to make a trade to fill Werth’s shoes, they’ve replaced Eaton from within; 26-year-old Michael Taylor, in his fourth big league season, has started 88 games in center field. Coming into this season, Taylor was a useful, if flawed player. In 2015 and 2016, Taylor hit 21 home runs in 748 plate appearances and stole 30 bases in 36 attempts and played good defense in center. But he also hit just .229, without enough power to justify giving a player with a .281 OBP and a strikeout rate in the 30s anything more than a role as a fourth outfielder.

This season, Taylor is one of dozens of players who’s benefited from hitting the ball harder and higher than ever before. His hard contact rate of 34.5 percent is a career high, and his ground ball–to–fly ball rate of 1.27 is a career low. Taylor’s reached career highs in home runs (16) and all three triple-slash categories (.274/.322/.497), which makes him well-suited to sit at the bottom of the lineup and drive in Rendon, Murphy, and Zimmerman after they’ve driven in Turner, Harper, and Wilmer Difo.

In addition to filling holes in the outfield, Kendrick and Taylor provide depth that, particularly considering the injuries the Nationals have suffered at the top of the order, has been the key to sustaining the highest-scoring offense in the National League.

“When you’ve got 1-2-3 [in the order] out, but 4-5-6 is still there, and the other guys step in, it’s a pretty good team,” Kintzler said.

With such a large lead in the division, the Nationals have the luxury of treating injuries to key veterans as extended auditions for youngsters or bench players, and in Taylor’s case, they’ve found the starting center fielder they hoped they were getting by trading for Eaton.

“I think the way we’re looking at it as a young kid is going to get a chance to show what he’s got in certain situations, and that’s great,” González said. “It gives him time and gives him a little cushion to work with.”

Even though the rotation’s been a strength for Washington this year, Nats starters haven’t had an easy go of it either. Scherzer and Strasburg have fought off nagging injuries, and no. 5 starter Joe Ross went down in July with a torn UCL and is out for the season.

Before Ross went down, the Nationals had dipped into the free-agent pool and picked up a familiar face: Edwin Jackson. In 2012, Jackson threw 189.2 roughly league-average innings for Washington, en route to the Nationals’ first division title. The following January he signed with the Cubs as a free agent, led the league in losses, and hasn’t qualified for an ERA title since. He earned himself his release in July 2015, which means he missed out on the franchise’s exciting playoff runs of the past two seasons.

This is the 15th season of a storied but itinerant big league career that started on his 20th birthday in 2003. Over that time, Jackson has been traded six times—including twice in the same day in 2011—and has signed seven free-agent contracts with six franchises since February 2012. All told he’s played for 11 different big league teams, including the Baltimore Orioles, who gave him three relief appearances in early 2017 before releasing him in mid-June.

The amount Jackson’s moved around obscures the fact that he’s accomplished a great deal in his 15 seasons: He’s won one World Series, pitched in another, thrown a no-hitter, made an All-Star team, and earned more than $80 million. So one wonders why he kept going after being tagged as not good enough to start for the Orioles, which is as damning a label as you can put on a pitcher.

“Love of the game,” Jackson said. “Love of being out there and competing at the highest level and playing against the best. The love of competition and camaraderie, being in the clubhouse—this is like a fraternity. It’s a family. It’s an orphanage. It’s a group of people coming from all walks of life, different backgrounds, different lifestyles—everyone’s coming in here to jell and be a family for seven or eight months out of the year.”

The Nationals gave Jackson, who hasn’t been a league-average starter since his last go-round with the club five years ago, a shot in the rotation, and he’s rewarded their faith with a 115 ERA+ in 58 innings over 10 starts.

“Edwin’s been fantastic,” González said. “He’s been a workhorse, carrying a lot of the load, and he’s been a lot of help since he’s been here.”

Jackson came up as a power pitcher, a hard-throwing fastball-slider type, but his 6.7 K/9 ratio and 94 mph heater aren’t special in this day and age, so he’s turned into a prototypical cagey veteran. Jackson is throwing his four-seamer just 35 percent of the time this year, a career low, and Brooks Baseball has tracked six distinct pitches from him this season—most starters throw four. Jackson says he owes his success so far this year to throwing strikes and trusting his defense to make plays behind him, and so far they have.

Jackson says all of this with a playful, almost mischievous twinkle in his eye. It’s the look of someone who knows he’s playing with house money, who’s seen his career flash before his eyes so many times that he isn’t scared of pitching in a pennant race anymore.

“Pressure’s what you make it,” he said. “At this point I’ve been in every situation. Pressure is not being with a team in spring training and having to see if I’m going to pitch this year. I feel like I’ve got nothing to lose and everything to gain.”

Every Nationals player I talked to said, in one form or another, that chemistry made it easier to overcome those injuries. Doolittle pointed out that winning builds good chemistry as much as the reverse is true, but the Nationals integrated midseason acquisitions like Kendrick, Jackson, and the three-headed relief monster; they nurtured young players like Taylor; and rather than panic when their stars got hurt, they cultivated a “next man up” attitude that staved off the fatalism you’d expect from a team that’s suffered three first-round exits and an August collapse in the past five seasons.

The Nationals have navigated the Ship of Theseus by managing expectations in a manner that itself looks paradoxical: Although the team as a whole expects to win, no individual player is expected to do all the heavy lifting on his own.

“Everyone who’s able to fill in a spot can’t think about who’s down,” Jackson said. “You have to think about the task at hand, and that’s to go out and win ballgames. That’s the approach everyone’s taken—you don’t have to step up and be the person you’re replacing, you just have to step up and do your part. Nobody has to go out and feel like they have to be Superman, just because you’re replacing someone who was an All-Star.”

Rather than worry about when Harper’s coming back, or whether Scherzer will get hurt again, the Nationals are imagining how good this team can be at full strength.

“Those are guys who are going to be back, and when they come back healthy they’re going to be unstoppable,” González said. “I wouldn’t even see it as ‘down’ as much as just getting some rest.”

For that reason, Jackson likes Washington’s chances better now than he did the last time he was in town.

“No disrespect to the 2012 team,” he said, “because we had a great team and great team chemistry, but I think this team is more talented—this team is stacked when everyone’s healthy.”