After a promising couple of months with the Boston Red Sox towards the end of last year, Rafael Devers has been a liability on both sides of the ball this year. Currently, his slash line reads an unsightly .230 AVG/.284 OBP/.408 SLG with a complementing 79 wRC+. The latter number means he has produced runs 21% below league-average, as a 100 wRC+ is average. He is a mediocre defender at best, but the “mediocre” label seems very generous. The 21-year-old is prone to way too many mental lapses at the hot corner. Put it all together, and the package Rafael Devers is bringing to the table is uninspiring.
Digging into his struggles
Leading up to his highly-anticipated MLB debut on July 25, 2017, Devers was universally touted as one of the best, if not the best, prospect in the game. He had been mashing at every level and, even in spite of some defensive questions, he got the call-up. In a small cup of tea with Boston in ’17, he managed to belt 10 home runs and churn a nice .819 OPS in 240 plate appearances. He possessed enormous power to all fields, which made up for his lackluster plate discipline.
Fast forward to 2018 and he still is a frustrating free-swinger, offering at 37.1% of pitches outside of the strike zone (O-Swing%). This is well above the league-average (30.1%) and has led to more strikeouts than last season. At this point in 2018, he has basically matched his plate appearance total from 2017 (232 and 240, respectively), so the samples, while still being fairly small, are useful for comparison.
As mentioned, he’s striking out more but he’s walking at virtually the same rate. The power production is not too far off, either, if you compare their isolated power from the past two seasons. He is actually swinging at a considerable amount of pitches in the zone, which should have increased his production if anything. Heck, the quality of contact is pretty much the same. The baby-faced third basemen still struggles with low and away pitches, though, and pitchers are exploiting that more this year. To be fair, he does not do very well with high and in pitches either. There are significant holes in his plate coverage. Check out how he’s being pitched this season, courtesy of Fangraphs.
How pitchers have attacked Devers in 2018
Now, check out how he’s fared against pitches in different parts of the zone in 2018.
How Devers has done against pitches in 2018
While reading these charts, it is important to keep in mind that these heatmaps are from a catcher’s view point. Devers is a lefty so, splitting the map down the middle, everything to the right would be “inside” so to speak. It is obvious pitchers are targeting him low and away, favoring that spot to get him out. It is also evident that he has struggled with high and inside pitches, but pitchers have not challenged him up there too much at this point. Although, if he does figure out how to hit low and away pitches, it seems self-evident where pitchers will try to get him out next. Baseball is a constant game of adjustments.
Anyway, his batting average is way down from .284 in ’17 to .230 in ’18, which probably corresponds with his drop in BABIP (batting average on balls in play) in the same span: .342 to .276. While a .276 BABIP is low, it does not offer up a huge beacon of hope that Devers will reclaim a lot of production he lost even with regression to the mean.
All that being said, there are two aspects of the left-handed swinger’s 2018 season that explain his struggles more than anything else.
To start, he simply has been very ineffective against fastballs this season, four and two-seamers. Devers has seen 321 four-seamers and has only accumulated a .222 average and .444 slugging percentage. Meanwhile, he has been demonstrably worse against 105 two-seamers/sinkers with a .160 average and .320 slugging percentage. Considering batters see more fastballs than any other pitch, yeah, that is concerning, especially since he was effective against the heat in 2017.
Opposite field struggles
The inability to hit fastballs has hindered his production, but, probably more salient to his lack of production, has been his opposite-field power disappearing. You have probably heard people gush about the immense oppo-power that Devers possesses since he entered the Sox’ system. The fact he is a left-handed hitter aided in the opposite-field power excitement, with the prospect that he would take advantage of the Green Monster.
Well, last season he was much more adept at taking balls the other way and did so with more authority and more frequency. His Oppo% (percent of batted balls to the opposite field) has fallen dramatically from last season. In 2017, he took 31.5% of batted balls to the opposite side (left field), while in 2018 he has just mustered 26.0% that way. Even when he has taken it the other way, it hasn’t been with the same pop. His spray charts from 2017 and 2018 are illuminating.
I count 10 doubles (the blue dots) to left field, which is the opposite way. Then, you have, at minimum, four homeruns to opposite field, but there is an argument to be made there are five, depending on how you view the one slightly to the right of all those doubles.
Remember, we are working with almost the same amount of opportunities (plate appearances) in both partial seasons, so these charts are important. He has only hit two homers the other way and just three doubles. In total, he has managed to collect five extra-base hits to the opposite side in 2018. You should see the discrepancy already, but the man hit 14 or 15 extra-base hits the other way in 2017, tripling his extra-base hit production from this year. That is a problem.
To be frank, this season Rafael Devers has not been all that good of an MLB player. His defense is maddeningly inconsistent and his offense has not been much better. It is pretty easy for me to sit here and interpret some graphs to diagnose the partial cause of his struggles, but it will be a whole lot harder to fix them. I am not sure if we will ever get a version of Devers that is not a free-swinger, even if Alex Cora is incentivizing him with Chipotle coupons, because there has never been a level where he has not been. He has been able to overcome his plate discipline woes before but he was a good fastball and opposite-field hitter then.
Regardless, people can’t lose sight of the fact he is just 21 years of age, with lots of growth on the horizon. The potential is there, especially on the offensive side of things and we have seen how alluring his opposite-field swing has been in the past. Boston should probably stick with him a little bit longer through these struggles and see if he can turn it around. It is not like they have great options to displace him if he were sent back down to Pawtucket for some polishing, although Brock Holt has been terrific this season. The leash is getting shorter for Devers presumably but Cora has shown he is willing to stick through pronounced cold streaks (Jackie Bradley Jr., Christian Vazquez and Drew Pomeranz). This will be interesting to watch as the season unfolds.