Where to rank Aledmys Diaz among MLB shortstops

It was not that long ago—thirteen months ago, in fact—that the St. Louis Cardinals, a largely competent and almost certainly above-average organization in terms of player evaluation, considered Ruben Tejada a more viable option to play shortstop regularly for their Major League club than Aledmys Diaz.

Diaz did not just exceed expectations in 2016—he shattered them. Although considered a mild disappointment for the first two seasons of his four-year, $8 million contract, as he had not reached the Major Leagues, Diaz easily justified the entire cost of the contract (not to mention the additional benefit of club control beyond the length of his initial deal) with his 2016 performance. By FanGraphs Wins Above Replacement, the rookie shortstop, in his age 25 season, was worth 2.7 wins, tied for 13th among MLB shortstops, though this is somewhat misleading—only one shortstop, Trevor Story of the Colorado Rockies, was worth as many or more fWAR as Diaz with fewer games or plate appearances (and barely—Story stood at 2.8). By Baseball Reference WAR, Diaz cracked the top ten, with none of the nine names ahead of him playing in fewer games than the surprising shortstop.

A reasonable fear entering 2017 was that Aledmys Diaz would regress—after all, in just one season, Diaz went from so lowly regarded that the Cardinals were willing to expose him to waivers all so that Dan Johnson (ultimately, I decided against adding an exclamation mark after his name, but you may mentally do so if you’d prefer one for effect) could join the team to being the second-best offensive shortstop in baseball as measured by wRC+. That Diaz was better than Ruben Tejada was a safe conclusion—but that he was a 132 wRC+ hitter?

So far in 2017, Aledmys Diaz has not been as productive as he was in 2016, though this is in and of itself not too disheartening. Would it be nice if he were actually as good of a hitter as Brian Dozier? Sure, but it also would not be reasonable to expect a season which was far beyond what previous seasons would suggest Aledmys Diaz actually is.

By the same token, using Diaz’s lesser 2017 as the standard by which to project his career is also unfair—after all, Diaz has played in far fewer games and had far fewer plate appearances this year compared to his full season of 2016. Combining the two and looking at Aledmys Diaz’s career marks to this point is not a perfect solution, as he could easily regress some more (improvement is also possible, but given his minor league track record, regression seems more likely). And over the course of his first 533 plate appearances, Diaz sported a career OPS+ of 128, meaning that he was 28% better than a league-average baseball player.

For the sake of comparison, let’s assume that Diaz is, more or less, what his OPS+ says he is. His current 74 wRC+ might make you hesitate to make such a call, and it probably should, but let’s just make this call for now. Let’s also assume that his defense is about what he has displayed throughout his time with the Cardinals—he’s not a Gold Glover, far from it in fact, but he is able to handle the position.

Now, peak Aledmys Diaz (or at least what we know his peak is) is a solid player in and of himself. His 3.5 bWAR in 2016 was tied for the 33rd best shortstop season in St. Louis Cardinals history. This may not, in and of itself, sound like a resounding accomplishment, but Diaz was just the 13th shortstop to reach this bWAR plateau in franchise history (for a point of reference, Ozzie Smith managed 3.5 bWAR or more eleven times as a Cardinal). Diaz was just the 7th shortstop to reach 3.5 bWAR at age 25 or before, and he was just the third Cardinals shortstop to do so post-World War II (the other two were Garry Templeton and Edgar Renteria). While Aledmys Diaz may not be elite in a historic context, his season did stand out as a rather impressive one.

Diaz’s Baseball Reference WAR stood at 3.2 through his aforementioned first 533 plate appearances. In a vacuum, this makes him a solid, above-average Major League player, and at 26, his current age, seemingly a promising young player—perhaps not a phenom, but part of the future of the position.

Unfortunately, Aledmys Diaz came along at an exceptionally loaded time in the history of the shortstop position. By the time it took Aledmys Diaz to reach 533 plate appearances, seven active shortstops younger than Diaz had more career bWAR.

• Francisco Lindor, 11.1 WAR in 1206 PA; born November 14, 1993
• Carlos Correa, 10.2 WAR in 1162 PA; born September 22, 1994
• Xander Bogaerts, 9.1 WAR in 2078 PA; born October 1, 1992
• Corey Seager, 8.6 WAR in 880 PA; born April 27, 1994
• Addison Russell, 8.5 WAR in 1197 PA; born January 23, 1994
• Marcus Semien, 7.0 WAR in 1594 PA; born September 17, 1990
• Jonathan Villar, 4.9 WAR in 1425 PA; born May 2, 1991

The case for Aledmys Diaz being at or even above the same level as these shortstops would be that Diaz was a late arrival, relatively speaking, in Major League Baseball, and that, if he continues to prosper as he has to this point in his life, he will be able to close the gap. But Diaz does not rate particularly favorably compared to this top young shortstops even on a rate basis.

Here are the eight shortstops ranked by bWAR per 600 plate appearances.

1. Corey Seager, 5.9 WAR
2. Francisco Lindor, 5.5 WAR
3. Carlos Correa, 5.3 WAR
4. Addison Russell, 4.3 WAR
5. Aledmys Diaz, 3.6 WAR
6. Marcus Semien, 2.6 WAR
7. Xander Bogaerts, 2.6 WAR
8. Jonathan Villar, 2.1 WAR

Aledmys Diaz ranks ahead of three solid young shortstops here, and if Diaz is able to maintain his brief career precedent, and it turns out that he is a better player than Semien, Bogaerts, and Villar, the Cardinals would and should be thrilled.

That said, the odds are very slim that Aledmys Diaz competes with the big four young shortstops in baseball: Correa, the very young prodigy from the Houston Astros; Lindor, nearly the best position player on a World Series champion Cleveland Indians team at 22; Russell, the superb-fielding Chicago Cubs shortstop with even more room to grow offensively; and Seager, third place in NL MVP voting as a 22 year-old rookie with the Los Angeles Dodgers.

It is unfortunate for Diaz that he came along at the same time as this glut of young superstar shortstops. If not for these once-in-a-lifetime talents, one could dream on Aledmys Diaz’s early production and that he may become a definitive, top-tier shortstop.

And while this is unlikely, he still has shown the ability to be a very good shortstop, and the Cardinals may still have a solid member of its core going forward, even if they don’t have Francisco Lindor or Carlos Correa. It is now up to Diaz to bounce back going forward through 2017 and prove that he can be this solid contributor, if not the next Alex Rodriguez.