We know about Rockies rookie shortstop Trevor Story and his remarkable start to the 2016 season. Recently, though, it's been Dodgers rookie shortstop Corey Seager who's announced himself rather loudly. Said announcement came in the form of five home runs tallied across a recent three-game span. Here's a quick look ...
The power bestowals of these two rookie shortstops raise the general matter of ... power bestowals of rookie shortstops. At present, Story has 15 homers on the season, and Seager has 14. As it turns out, just 11 rookies have hit 15 or more homers in a season while spending at least 75 percent of their games at shortstop. Story, obviously, is one, and Carlos Correa made the list last year. Seager will join then at any moment.
The record for home runs by a rookie shortstop meeting the above criteria -- i.e., at least 75 percent of total games at shortstop -- belongs to Nomar Garciaparra of the Red Sox, who hit 30 homers in 1997. The NL record belongs to Story's mile-above-sea-level predecessor, Troy Tulowitzki, who hit out 24 with the Rockies in 2007. Had Correa played more last year (he hit 22 home runs in 99 games), then he very likely would've threatened or passed Garciaparra's mark.
That brings us back to Story and Seager. If you simply prorate current playing time and homer rates over a full season, then Story's on pace for 43 spanks, while Seager's tabbed for 39. Those tallies, to say the least, would comfortably surpass Garciaparra's.
That's not how it typically works, though. A better guide to future outcomes are projection systems. On that point, the ZiPS rest-of-season forecasts available at FanGraphs tab Story for 15 homers the rest of the way, which, conveniently enough, would mean he'd tie Garciaparra's record. Seager, meantime, projects for 15 homers the rest of the way, which would mean he'd come up on shy of the record.
In terms of the history in question, Story's home environment, Coors Field, is obviously more accommodating than Seager's. Taking a broader view, though, Seager profiles as the more valuable talent long-term. Story's swing is legit, and his power is sustainable. Seager, though, is roughly a year-and-a-half younger, was more highly regarded by scouts coming up through the ranks, and this season is besting Story in terms of OPS+ (which is park-adjusted) by a margin of 138 to 113. As well, Story's cooled off since homering seven times in his first six games.
Story's going to be a useful player for a long time, but Seager may be a future superstar. Right now, though, they're mounting a dual assault on rookie shortstop history.
(Data via the Baseball-Reference Play Index)
