This past season was an exciting year for baseball, for a variety of reasons. Young phenoms like Mike Trout and Bryce Harper dominated the league — the fourth time for Trout, and the first for Harper after some good-not-great years to start his career. The Kansas City Royals proved more than a few people wrong, made it back to the World Series and this time managed to bring it home, and another underdog was right there with them in the New York Mets. It’s nice, at least for most of us, to see some fresh cream rise to the top, and that certainly happened this year.
For me though, the most exciting aspect of the 2015 campaign was the emergence of a tremendous group of rookie ballplayers, many of whom wasted no time making an impact for their respective clubs and flashing the enormous potential that they possess. Because of that, I was curious about how the 2015 rookie class stacks up against other rookie classes throughout history.
Prior to actually doing the research, I expected the class to certainly be in the upper quarter, or so, and wouldn’t have been surprised to see them somewhere in the top ten in terms of rookie league averages in each MLB season, from 1871 to now. What I didn’t expect was to find was the 2015 group to be tied for the 5th best wRC+ in all of professional baseball history at 90, only trailing four groups from the 1800s (1871 leads the way at 98 wRC+ as I assume everyone was considered a rookie in the National Association’s inaugural season, but also up there are 1879, 1882, 1880 and 1899).
Now, I don’t want to take anything away from baseball of the nineteenth century, but I feel pretty comfortable in saying that the 2015 class was likely superior to all of those seasons listed above. The fact that they all happened to be in the early years of the game suggest there are some issues going on that wRC+ isn’t properly accounting for, and the game was so different back then that it almost makes it not worth discussing for our purposes here.
This is corroborated by the fact that the closest rookie classes of the last 100 years is that of 1987, which holds an 87 wRC+, and that of the 2011 class, which featured the likes of Lucas Duda, Eric Hosmer, Jason Kipnis and Allen Craig. And I haven’t even mentioned the fact that Fangraphs WAR has the 2015 group at a total of 84.7 WAR, 35 wins better than second place 1987. That is an absolute blowout, and very much comes from the high defensive ratings that Fangraphs gives them — players continue to get more and more athletic, and an increased emphasis is being placed on defense, it would seem.
All in all, and perhaps most importantly, I don’t think many of us would be surprised if guys like Kris Bryant, Kyle Schwarber (the Cubs are so lucky), Miguel Sano, Carlos Correa and more than a few others have better careers than some, if not all, of those 2011 rookies — and perhaps even better than the 1987 rookies, which include Mark McGwire, Fred McGriff and Rafael Palmeiro — and that paints a pretty vivid picture of how special this rookie class was, and could be going forward.