“Most [players], they kind of tell you who they are,” says Scott Servais, the Angels’ assistant GM of scouting and player development. “[Nelson Cruz] is the ultimate exception to the rule.” In Servais’s current role, Cruz is a threat: the big bat in Seattle blocking the Angels’ path to the playoffs, and the best hitter in the American League to this point, with a ridiculous .351/.406/.715 line and an MLB-leading 16 home runs. But in Servais’s former role as the Rangers’ senior director of player development, Cruz was a pet project — one that, at the time, seemed unlikely to pan out.

Like a lot of baseball rules, the one Servais is citing is unwritten, but no less real than the ones that cause brawls and bruised batters. He’s seen the studies, and the consensus is clear: Old minor league players aren’t prospects. The average major leaguer debuts at age 24, and a 28-year-old rookie is nearly three times as likely as a 21-year-old rookie to wash out after one year. It follows that one can learn a lot about a player from his birthdate without knowing anything about his ballpark, background, or build. For high school draftees, a year can mean the difference between being a bust and making the big leagues. And even in the upper levels, a few years can separate an exciting stat line from an identical one that’s easily dismissed. By necessity, every player development director is part instructor, part actuary, pulling for each player but also keeping an eye on the clock. As Ron Hopkins, a current scout for the Pirates and the Rangers’ former scouting director, puts it, “Most guys, by 29, they’re either established or coaches.”

For much of his career, that calculus seemed to exclude Cruz from consideration as a star. Nothing about his background says he belongs among the best hitters in baseball. But he crashed the former top prospects’ party, and now he’s lingering long after we figured he’d leave. And with every swing, he looks less out of place.

Cruz was established by Hopkins’s age-29 cutoff, but only barely: He turned 29 halfway through 2009, his first full season in the majors. Technically, that was his age-28 season: The standard cutoff for seasonal age is June 30, and Cruz was born July 1. Any appearance of youth that quirk of the calendar conferred was probably appreciated, because Cruz was behind the curve as soon as he signed with the Mets as an amateur free agent out of the Dominican Republic in 1998 for the small sum of $15,000.

“[Cruz] got started late in the game,” says Mariners GM Jack Zduriencik, who signed Cruz to a four-year, $57 million deal in December. “He was a highly touted basketball player, and so he was just one of those kids that took a little while to get the game going. When he originally signed with the Mets, the scout that signed him, Eddy Toledo, used to always keep him out of games when the hierarchy would come down from New York, because he was a talented kid but he was still somewhat on the crude side.” Cruz’s lack of polish persisted well into his pro career. “I remember seeing him in the Midwest League in 2003, and while you could see the physical talent, he had no idea what he was doing in the batter’s box,” says SB Nation prospect analyst John Sickels.

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Cruz was traded three times before he broke through. The first trade, at the 2000 waiver trade deadline, sent Cruz from New York to Oakland for utilityman Jorge Velandia. Four years later, Cruz’s stock still hadn’t appreciated past utility-bait, and Oakland moved him to Milwaukee as part of a package for Keith Ginter. That’s a depressing sentence just to type, but Cruz alone couldn’t bring back Ginter, who hit .161/.234/.263 for the A’s the following season and never made it back to the big leagues. The other guy Oakland gave up, Justin Lehr, had ranked 20th on Baseball America’s A’s top prospects list entering 2004. Cruz couldn’t crack the top 30.

In 2005, his first season with Milwaukee, Cruz posted a combined .289/.385/.537 line across Double-A and Triple-A, which was enough to earn him Milwaukee’s minor league player of the year honors, a brief September call-up, and a jump to eighth on the Brewers’ prospect list the following spring. Cruz was still nowhere near an overall top-100 ranking, but his higher placement may have helped catch the eye of Rangers GM Jon Daniels, who asked that Cruz be included when his team traded Francisco Cordero and complementary players for Carlos Lee at the end of July 2006.

“We certainly saw a potentially starting major league corner outfielder,” says FanGraphs author Tony Blengino, who was then the Brewers’ assistant scouting director. But, Blengino adds, “I don’t think any of us thought he’d become what he became.” The Brewers had Corey Hart, and Ryan Braun, who was atrocious at third, wasn’t long for the infield. “At the last minute it was like, ‘OK, if you want to make this trade, we need Cruz,’” Blengino says. “It was one of those things where we had some depth of younger, we thought higher-upside players to play the outfield corners.”

In October 2011, then–Baseball Prospectus lead prospect writer and current Astros director of pro scouting Kevin Goldstein previewed that year’s Tigers-Rangers ALCS with “scouting hindsight,” recalling how each player on the postseason roster had been perceived in the minors. Goldstein’s blurb about Cruz said, “Some skills there, but he’s kind of older and on his fourth organization for a reason.” Cruz’s early results with the Rangers reinforced that perception. Cruz had been batting .302 with 20 homers in Triple-A at the time of the trade, but he hit .223/.261/.385 in 41 major league games after reporting to Texas. The pattern continued the following year: Cruz gained and lost an everyday job, hitting only .235/.287/.384 in 333 big league plate appearances despite recording a 2014-esque .352/.428/.698 line in almost 200 Triple-A plate appearances in the same season. At the end of 2007, Cruz was 27 years old, squarely in the physical prime for most players, but had a career .666 OPS in almost 500 plate appearances, half of them accrued in hitter-friendly home parks. The satanic OPS was overkill; Cruz’s MLB experience had been hellish enough.

The really perplexing part was how much better Cruz should have hit, particularly in 2006 and 2007, in light of his other-end-of-the-spectrum minor league stats. Cruz’s offensive performance in the majors fell far short of the figures suggested by ESPN analyst Dan Szymborski’s Major League Equivalencies, which use empirical data on all players who switch leagues to estimate what a player’s minor league line would have translated to in the majors. The table below contains the MLEs for each of Cruz’s extended stays at a minor league level from 2004 to 2008. “MLE OPS” is the translation, and “MLB OPS” is the actual result.

The Pacific Coast League, where Cruz spent his time in Triple-A, is an offense-friendly environment. Even so, based on the numbers, Cruz should have helped the Rangers at the big league level before he did. His peekaboo bat baffled everyone. “Every time we sent him down, the next night he played, he’d hit a home run or two,” says Rudy Jaramillo, the Rangers’ longtime hitting coach, who admits that he couldn’t tell whether Cruz would ever click. “He was unbelievable.”

Early in 2008, Cruz bottomed out: After he slumped in spring training, the Rangers decided to break camp with switch-hitting he-man Jason Botts, a 27-year-old with a career .665 OPS. Not only had Cruz lost the battle, he’d been bypassed by a player whose big league stats were as underwhelming as his own. Because Cruz was out of minor league options, the Rangers had to place him on waivers to send him back to Triple-A, which forced them to expose him to the entire, talent-hungry league. For a $20,000 fee, any team in baseball could have claimed him and plugged him into its lineup later that day. No team thought he was worth it. “Nobody felt like this guy could hit,” Hopkins says. “Scouts aren’t stupid, and teams aren’t. They could see the size, the tools, and the raw power. He had sample sizes, and they weren’t good — lots of strikeouts.”

Cruz could have taken the hint and left to play in Japan, as Botts, who played only 15 more games in the majors, did later that year. Instead, Cruz decided to stay. And the Rangers could have given up on him, accepting the growing belief that he was a “Quadruple-A” hitter who could feast on mistakes and punish minor league pitching but would always be too undisciplined and strikeout-prone to succeed against the elite. Instead, Servais saw someone worth saving. “There were some things with his swing that weren’t working,” Servais says. “We had exhausted all of our options and outrighted him off the roster. … When he was back in Triple-A, kind of his last go-round, being the director of player development at the time, it was kind of a last shot sitting down and asking him to make changes in his swing. Physical changes, not just approach.”

Servais asked Cruz to try two things. The first was opening his stance, turning his body toward the pitcher like Andres Galarraga, another hitter who had reinvented himself (and who, with an assist from Coors Field, became one of only three players to hit 40 homers for the first time at an even more advanced age than Cruz was when he managed the feat¹). Servais suspected that the pitches Cruz flailed against revealed the root of his problems. “When the ball was down, out over the plate, he was fine. He could handle the pitches. It was just when the ball was elevated he cut his swing off a little bit, so it was an opportunity to see the breaking ball a little bit better, getting him in a more consistent athletic position when he got to the hitting position.”

But the biggest thing, Servais says, was “flattening out his swing so he could catch up to the plus fastballs at the big league level. When they got elevated, he was always underneath the ball. This helped him get flat through the ball, and that’s where his power had a chance to play.” Before the changes, Cruz “was more or less crashing with the ball in a sense, trying to run into it,” Jaramillo says. But Cruz was strong enough that he didn’t need to have Charlie Brown’s swing path to power the ball. He just needed to make contact.

A mechanical makeover is more likely to stick when in-game improvement comes quickly. In Cruz’s case, it did. He hit .380/.537/.785 with nine homers in April 2008 and slowed down only slightly over the rest of the Triple-A season. When he returned to the majors in August, his performance finally carried over, matching the statistical translations and then some. Jaramillo credits a mix of mechanics and mental maturation, too intertwined to untangle. “You start repeating those good mechanics and timing and you end up getting confidence,” Jaramillo says. Jaramillo guarantees that before the mechanical changes, when Cruz’s stats still seemed like the product of a split personality, “the swing was two different swings. One was tension-free and the other was straight tension.”

Hopkins recalls that legendary scout Mel Didier — who helped make Gary Carter a catcher, signed Andre Dawson, and served as a senior adviser for Texas in the 2000s — was among those in Cruz’s corner when the outfielder’s future was in doubt. Servais says there was something of an organizational schism surrounding the slugger’s abilities. “I think the people that had been with him through the minor league level had seen so much production that it was really hard for them to think this couldn’t work with this guy at the big league level, even though obviously the big league manager, general manager, and stuff really were like, ‘This isn’t gonna work.’ But I guess that’s why you have minor league people. That’s why you have player development people willing to try new things and never exhaust hope. … This wasn’t just an ordinary guy. This was a guy who could hit a ball 450 feet if everything was right.”

Naturally, much of the credit goes to Cruz, who’s coachable, persistent, smart, and athletic, a mixture of makeup and physical skill that allowed him to adjust in a way that a set-in-his-ways slugger like Wily Mo Pena wouldn’t. “[Cruz is] one of my favorites just because he was willing to try it,” Servais says. “So many guys say, ‘It might not work, I might embarrass myself.’ He was just like, ‘Heck, I’m going to go for it.’ That’s hard to find in today’s game.”

Since 1950, only 17 players have had their first 500-plate-appearance season at age 28 or later, like Cruz, and hit as well as he did in that first full-time year and the following five years, as measured by Baseball Prospectus’s Batting Runs Above Average. Most of the players ahead of him fit into understandable boxes. Some were catchers (Jorge Posada; Mickey Tettleton; Chris Hoiles; Darren Daulton) who often break in late because of their position’s greater defensive demands. Some were injury-prone (J.D. Drew) and underappreciated or mismanaged (Jose Cruz, Ben Oglivie). Some were international free agents (Hideki Matsui) or players who missed time because of military service (Jim Lemon). Some were mid-’90s Indians who were blocked by bigger stars (Brian Giles,² Jeromy Burnitz). Not many took so long because they flopped as convincingly as Cruz did in his first couple of cracks.

The best recent comp might be Ben Zobrist, a better overall player than Cruz who has some things in common with him: Zobrist hit well in the minors but experienced the same early major league stumbles that seemed to vanish following a swing change. Cruz had a .230 True Average over 477 PA in his first three partial seasons; Zobrist had a .228 True Average over 530 PA in his. Since 1950, 48 players have finished their third MLB season (of any length) with a True Average of .240 or worse and gone on to accrue at least 3,000 PA. As one would expect, it’s an uninspiring group. Cruz’s career stats haven’t yet been dragged down by a decline phase, but for now he leads the list. As Servais says, he’s an exception.

Despite Cruz’s belated success in Texas and Baltimore, the deal Seattle gave him was widely panned, more for the fourth year that will keep him under contract past his 38th birthday than for the money needed to secure the short-term upgrade he was bound to provide at one of the Mariners’ perennial soft spots. “He won’t hit 40 homers again, obviously, and I’ll go out on a limb and say he won’t again reach 30,” Blengino wrote in a well-reasoned post that seems overly pessimistic in hindsight.

Thus far, though, Cruz has propped up the Mariners, producing 25.3 percent of the team’s total Weighted Runs Created.³ No other player has accounted for as large a portion of his team’s production in 2015, which reflects well on Cruz and poorly on most other Mariners ([cough] Robinson Cano [cough]). For a few years early this decade, Safeco Field was one of the hardest places for right-handers to hit home runs, but it’s played closer to neutral over the past two seasons following left-field fence adjustments. Park factors might not apply to Cruz the way they would to a typical player: As Adam Jones said before Tuesday’s game, in which Cruz returned to Baltimore and drove in three of Seattle’s four runs with a fly ball over the left-center-field fence, “Put him in the Grand Canyon and he’d hit it out of there, too.” Of 136 players who’ve hit at least 15 fly balls for which we have distances recorded by Statcast, only Bryce Harper and Chris Davis have topped Cruz’s average of 355.3 feet.

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Cruz has already exceeded expectations after breaking in late. Now he’s defying the aging curve in a different way. “Someone might look at Nelson Cruz and say, at this age, based on typical-type players, he could see a decline,” Zduriencik says. “But he just seems to be like one of those guys that is just really kind of hitting his stride. … I think what this might suggest is that he keeps himself in great shape, he’s a great liver in terms of how he handles himself, his rest, his preparation for the game, and this is going to continue for a while. There was a selling point on bringing him to Seattle, which is he is not your typical 34-year-old. He’s a guy that is a little bit younger based on his career, certainly on his lifestyle and how he carries himself.”

When a GM feels the urge to splurge, it’s easy for him to convince himself that the player he wants is exempt from unbreakable laws. In Cruz’s case, though, it sounds slightly less like wishcasting, in that the typical aging curve has never done a great job of predicting his career. Age is supposed to increase injury risk, but after making six trips to the 15-day DL from 2009 to 2011, Cruz has missed a total of three games because of injury since. Of course, if Grantland had a comments section, one could undoubtedly scroll down and see someone speculating about whether Cruz, who was suspended for 50 games in 2013 for taking a banned substance as part of the Biogenesis sting, has found another artificial fountain of youth. Statcast can’t sample Cruz’s blood chemistry, but he’s never lacked strength: Hopkins, who saw Cruz at age 21 in 2002, says that even then, “He caught your eye because he was big and had raw power, and when he ran into a ball he could hit it a long ways.” And performance-enhancing hitting sessions with Servais aren’t banned by the Basic Agreement.⁴

“Every year, there’s a player that shows up in spring training, plays real well, and somebody will bust out the old Quadruple-A player label,” Blengino says. “And sometimes it applies.” Cruz could have walked away with that label — and had the Rangers been a better team at the time, Servais says, the struggling slugger might not have had a choice. But there’s always been one thing about Cruz that makes teams willing to forgive his flaws. “He was old for his level all the way,” Blengino says. “But he hit the crap out of the ball.”

Thanks to Rob McQuown for research assistance.

1. The other two: Hank Sauer and Cy Williams.

2. Giles’s six-season BRAA total dwarfs all of the other late bloomers’: The gap between him and the second-ranked Drew is bigger than the gap between Drew and no. 34 Shane Mack. In that period from 1999 to 2004, Giles was the 10th-best hitter in baseball.

3. Last year, Freddie Freeman led all players in personal wRC share, generating 19 percent of the runs produced by the moribund Braves.

4. Luckily for Servais, the Angels are almost the only team that Cruz hasn’t crushed.