The 2017 Arizona Diamondbacks were an unexpected delight, an eventual playoff team that was projected to be near the bottom of the NL West before the season. They had star power to burn; with Paul Goldschmidt and A.J. Pollock anchoring the lineup and Zack Greinke and Robbie Ray at the front of the rotation, the team had a top four to rival any team in baseball. After that, though, the drop off was severe. Maybe you could squint and see greatness in Jake Lamb, maybe you believed in the Shelby Miller bounce back, but the depth simply wasn’t there.

Those Diamondbacks made the postseason and won the Wild Card game, fueled by a deadline trade for J.D. Martinez, but their stars-and-scrubs construction was worrisome. Pollock missed time with injury, David Peralta didn’t take a step forward, and the cupboard generally looked bare. While the team’s pitching staff looked more promising thanks to breakouts from Patrick Corbin and Zack Godley, it wasn’t built to last. Corbin was only a year from free agency, Greinke was getting older, and Godley was more league average than a star in waiting.

By the end of 2018, that iteration of the Diamondbacks was no more. Pollock and Corbin left in free agency, Goldschmidt was a Cardinal, and the team made no secret that it was shopping Greinke. For those of you keeping score at home, that’s all their stars other than Ray, and he had underperformed massively in 2018. We baseball fans are pattern matchers, and this pattern is an easy one to spot: it was time for a tank and rebuild.

Well, a funny thing happened on the way to the bottom of the standings. The Diamondbacks, projected for the fourth-worst record in the NL before the season, are clinging to the fringes of the playoff hunt, with a 5.3% chance of reaching the Wild Card game. They’re 75-71, on the verge of putting together their third straight winning season. Most impressively, they’re doing it with an entirely new cast of characters.

Here’s the complete list of Diamondbacks who had 100 plate appearances or batters faced for the team in 2017 and are still around in 2019 (excluding Greinke):

Holdover Hitters, 2017-2019 Player 2017 wRC+ 2017 WAR 2019 wRC+ 2019 WAR Jake Lamb 111 2.5 88 0.2 David Peralta 104 1.9 106 1.7 Ketel Marte 89 0.7 150 6.9 Nick Ahmed 76 0.2 96 2.7

Holdover Pitchers, 2017-2019 Player 2017 ERA 2017 WAR 2019 ERA 2019 WAR Robbie Ray 2.89 3.3 4.30 2.2 Zack Godley 3.37 3.5 6.39 -0.1 Archie Bradley 1.73 2 3.90 0.9 T.J. McFarland 5.33 0.2 5.03 0 Andrew Chafin 3.51 0.7 3.96 0.9

Ketel Marte is a holdover from the old team and one of the best players in baseball this year, but he hardly contributed to their 2017 success. In 2017, in fact, the trade that netted Marte looked quite bad, as Mitch Haniger and Jean Segura had star turns for the Mariners while Marte toiled in Triple-A.

Trades are a wonderful way to discuss the new look of the Diamondbacks. Current GM Mike Hazen joined the team after the 2016 season, and he hasn’t been shy about shaking things up. In fact, of the 13 players who have contributed 1 or more WAR to the team this year, eight were acquired in trade, free agency, or off waivers since the beginning of Hazen’s tenure. That doesn’t count the J.D. Martinez trade or the return for Greinke, either. To look at the new Diamondbacks, let’s look at how Hazen brought in those eight players.

Ketel Marte and Taijuan Walker for Segura, Haniger, and Zac Curtis

Even three years later, it’s hard to say who won this trade. Haniger has been excellent but injury-prone for the Mariners. He played a full season in 2018, but 2017 and 2019 have been interrupted by stints on the IL. Jean Segura posted a 111 wRC+ over two seasons with Seattle before being traded for Carlos Santana and J.P. Crawford. Zac Curtis — well, Haniger and Segura have been good.

The Diamondbacks haven’t been afraid to trade away good young players if they like the return. Segura was a pending free agent (though he signed an extension with the Mariners), but Haniger was still a rookie at the time of the deal. In exchange, the team got one of the best players in the NL today. Marte scuffled with the Mariners in 2016, but had a history of hitting in the minors and could play across the defensive spectrum. He started 2017 in the minors but has gotten better every year in the majors. 2019 might be his career year, but he looks like a star for years to come, and is signed to a team-friendly extension that could keep him in Arizona through 2024.

As for Walker, he’s a pitcher, which means he’s always a risk. After a solid first year in Arizona, he tore his UCL in just his third game of the 2018 season. When he could see the light at the end of the rehab tunnel, he sprained his shoulder capsule, which pushed his timetable for a return back from early this year to most likely 2020. It’s a serious blow for a fun, effective pitcher, though he’ll hopefully be back at full strength next season.

This trade almost deserves its own article, and it’s not even clear if it helped the team on net. Would they have preferred Haniger to Marte over the last three years? Would they have signed Jean Segura to an extension, as the Mariners did? What this trade shows is that Hazen hasn’t been afraid to make challenge trades, sending out excellent players with team-friendly contracts if he thinks the player coming back justifies it.

Eduardo Escobar for Jhoan Duran, Ernie De La Trinidad, and Gabriel Maciel

The Diamondbacks had playoff aspirations in 2018. They were 57-48 when they traded for Eduardo Escobar, two games out of the second Wild Card spot, and only 1 1/2 behind the scuffling Dodgers. Though they missed the playoffs, they signed Escobar to a contract extension at the end of the season, and he’s been excellent this year.

Escobar’s breakout is a modern success story. After years as a serviceable glove-first infielder with groundball tendencies, he overhauled his swing, started hitting fly balls, and became a power hitter. The offensive environment has something to do with it as well, but after never hitting more than 12 home runs in a season before 2017, he’s posted 21, 23, and 34 home runs respectively the last three years. His swing-heavy profile carries some risk, but between making a lot of contact and playing good defense, he projects to be a valuable piece going forward.

Carson Kelly, Luke Weaver, and Andy Young for Paul Goldschmidt

Trading the face of the franchise is never easy, but this trade looks like a win for the Diamondbacks, at least so far. Carson Kelly had been the best catching prospect in baseball for years, but with Yadier Molina signing a contract extension and Andrew Knizner nipping at his heels, he was surplus for the Cardinals. He’s been above average as a hitter and framer, which should be no surprise given his pedigree.

Luke Weaver had a nightmare 2018 with the Cardinals, but has performed at every level, including the majors: he has a 3.89 FIP and 4.8 WAR in 300 career innings. His profile has warts, as he leans heavily on his fastball and changeup and doesn’t have a true breaking ball, but he gets strikeouts and whiffs at a solid rate despite that. He might never develop into a top-end starter, but his changeup and command give him a high floor. Despite an elbow injury that cost him two thirds of the season, he’s the third-best Diamondbacks pitcher by WAR this year.

Andy Young was a throw-in, an older prospect who has done nothing but hit. He projects as depth for the 2020 team. Overall, none of these players are likely to be as good as Goldschmidt was, but two of the three look like above average starters for years to come. By going wide in the return, the Diamondbacks replaced Goldschmidt’s production while setting the team up to compete in the future.

Zac Gallen for Jazz Chisholm

This trade might be even harder to figure out than the Marte/Haniger trade. Zac Gallen took a huge step forward this year, striking out everyone in Triple-A and riding a strong groundball rate to a 1.77 ERA (3.36 FIP) in the land of infinite home runs. That’s significantly better than his previous track record, where he recorded worse numbers in more pitching-friendly environments. He’s been excellent for the Diamondbacks, getting a boatload of swinging strikes and groundballs, and might be their second-best pitcher right now.

Chisholm might be even better than that. A smooth-fielding shortstop with real power who Eric and Kiley currently have as the 29th best prospect in baseball, his ceiling is tremendously high. Also tremendously high: his strikeout rate, which stands at 30.1% for his minor league career. He’s a boom-or-bust prospect, who might be a star but might also never make enough contact to stick. He’s performed well since being traded to Miami, albeit in only a 94 PA sample.

Christian Walker Claimed on Waivers

An older, right/right first baseman with no history at the major league level doesn’t sound enticing, but Walker has been useful for the Diamondbacks, hitting for enough power to make up for his strikeouts. He’s nearly replicated Goldschmidt’s 2019, in fact, and even if he doesn’t keep up his current form, he’s shown he can hit at the major league level. Not bad for a waiver wire pickup.

Merrill Kelly Signed in Free Agency

Signing pitchers who have performed well overseas has worked out for Hazen. The team acquired Kelly on a low-risk, two-year deal with two team options after he pitched well in the KBO. He’s not a star, but he’s delivered a league-average performance, essential for a team that has lost Greinke, Corbin, and Walker for various reasons in the past year.

Jarrod Dyson Signed in Free Agency

The Diamondbacks signed Dyson to a two-year contract before the 2018 season. He was slowed by injury in 2018, but has been adequate if not inspiring in 2019, riding his speed and defense to 1.2 WAR despite a 73 wRC+. He’ll be a free agent after this year, and at 35, he might not be a part of their 2020 plans.

The point of all these transactions isn’t that Hazen has been perfect since taking over the team. It’s not clear who did better in the Marte and Gallen trades, and Jhoan Duran, who Eric and Kiley have ranked 85th overall, might yet make the Escobar trade seem short-sighted. Hazen’s approach, though, has been interesting. In every one of these trades, he’s targeted players with high floors, players who are locks to contribute at least something to the major league team.

The team he took over had vanishingly little depth. In 2016, only five Diamondbacks accrued even 1.5 WAR. In 2019, that number has swelled to 10 with three weeks of the season remaining. Ketel Marte turning into a star has certainly been a pleasant development, but even ignoring that, the team hardly looks like it used to. The 2017 Diamondbacks were paper-thin — injury or ineffectiveness by their stars would be devastating. The current team is essentially that team’s opposite.

Does this style of team construction work long-term? That remains to be seen. The 2020 outfield is wide open, while the infield has, if anything, too many players for not enough spaces. Josh Rojas, part of the return for Greinke, could force himself into the discussion, but he’s still an unknown quantity. Bringing in a free agent (Marcell Ozuna? Yasiel Puig?) seems reasonable, but until that happens, the position feels like a weakness. The Dodgers are a formidable foe, and the NL postseason picture will remain crowded.

Personally, though, I enjoy this style of team building. Between the Brewers and the Diamondbacks, we’ve now seen two teams retool on the fly without a true down cycle by trading for depth and supplementing it with free agency signings. Sure, the Brewers were lucky Christian Yelich became a monster and Arizona is lucky that Ketel Marte took a giant leap forward this year. But luck is involved in any great team, and that, combined with the fifth best farm system in baseball after a potentially franchise-altering 2019 draft, seems like a good starting point. Any strategy that minimizes the amount of time spent not trying to win is great in my book.