Lets get a few things out of the way. First, Walker Buehler had a legitimately great rookie campaign and I don’t want to discount that. In posting a 2.62 ERA and 3.04 FIP while striking out 9.9 batters per nine on his way to a 3.3 fWAR season, Buehler established himself as one of the better young pitchers in the entire league last season. In almost any other year, he would likely run away with the NL Rookie of the Year title. Big kudos to him.
Second, this article is going to focus solely on the two players that have a realistic chance of winning Rookie of the Year in Ronald Acuna Jr. and Juan Soto. There is not likely to be a clear answer to both who is the better player right now between Ronald Acuna Jr. and Juan Soto nor will there likely be a clear answer as to who will be the better player long-term. My adoration for Acuna is well-documented at this point, but discounting how awesome Soto was as a 19 year old seems silly to me. Also, this piece will not talk about guys like Joey Wendle, Harrison Bader, Brian Anderson, Shohei Ohtani, Vladimir Guerrero Jr. or others because....well, I don’t want to. If you want a pretty sweet historical comparison as to how Acuna’s rookie season stacks up to other great rookie campaigns, Matt had a sweet piece go up earlier today that you should read.
At this point in time, it appears as though Ronald Acuna Jr. is the favorite to win the award. Some of this is due to narrative-driven momentum. Acuna’s arrival and subsequent breakout helped propel the Braves to a surprise division win, etc etc. How a player does statistically is the most important factor, but voters are often swayed by how well a player’s team does when they are deciding close races fair or not. Fortunately (and unfortunately for Soto), the Nationals barely finished above .500 and were a disappointment overall even though that was far from his fault.
That said, there is also a very compelling, while very, very close, case that Acuna was the better player anyways between the two. Below are some very general categories to compare the two as we await the announcement of the National League Rookie of the Year.
This is the closest of the two categories and both players will have their supporters here. Acuna’s power numbers were superior (Acuna’s .259 ISO outpaced Soto by 34 points), but Soto’s on-base percentage was a good 40 points ahead of Acuna’s .366. The two players had nearly identical counting stats (Acuna had a one point lead in batting average, scored one more run, had just a few more hits, etc.). However, the slight edge strictly at the plate goes to Soto as his wOBA (.392 vs. .388) and wRC+ (146 vs. 143) were both just slightly ahead of Acuna due primarily to his on-base prowess. It is worth mentioning that if Acuna’s production rates were similar to the rampage he went on in the second half, he would have won this category handily and I have no issues with someone giving him the nod here based on that alone.
Conclusion: Very slight edge to Soto
This is an area where Acuna was just better than Soto. Acuna’s BsR score (Fangraphs’ measure of how many runs a player generated above or below average with their baserunning) was decisively in Acuna’s favor with him winning 2.8 to 2.0. For those into more traditional counting stats, Acuna stole 16 bases during his rookie campaign while Soto stole just five bags. Acuna being better here also passes the eye test as he is clearly the faster runner and is willing to use that speed to be aggressive. It will result in some unfortunate outs at times, but overall this is a clear win for Acuna.
Conclusion: Acuna > Soto
Finally, we reach defense which is another edge for Acuna. Soto is not a particularly strong defensive player and played every game in left field which hurts his overall defensive value anyways. In addition to ranking below Acuna generally in terms of defensive rating, he was a net negative in terms of defensive runs saved with -5 on the season. Acuna, on the other hand, wasn’t particularly strong defensively in left field but showed out in center and right field when he got playing time there. As a result, he was a net positive defensively with 4 defensive runs saved altogether. This is also an area again where this passes the eye test as Acuna had several highlight reel catches and assists whereas Soto isn’t necessarily known as a strong defensive player.
Conclusion: Acuna > Soto
There are other factors that come into play here including name recognition/star power that are worth mentioning when one is predicting who will actually win the award which is not always the same as who SHOULD win the award. Soto jumped into the majors with a bang as a teenager and rightly got a lot of love for his torrid start. However, his star faded somewhat as Acuna began to emerge and the Nationals’ playoff hopes dwindled. Acuna’s at-bats became appointment television and started getting national recognition whereas we did not see that as much with Soto. If this vote ends up being more lopsided in Acuna’s favor than it should, this is likely why.
The best to draw from this is that the National League was treated to one of the better Rookie of the Year races we will likely ever see. This wasn’t a case of picking which .260 hitting outfielder with some power deserves the award the most or having to pick a pitcher with eh numbers but happened to win 14 games. Both Acuna and Soto look like stars in the making and their 2018 seasons were absolute joys to watch. Fortunately for all of us, it looks like we will get to see them do battle for years to come.