Rafael Devers: a tale of two halves

Rafael Devers has been everything that the Red Sox needed at third base. As I wrote early in the season, the team has gotten very little production from the hot corner since trading away Kevin Youkilis in 2012 so that they could make Will Middlebrooks their everyday third baseman. Up until Devers got the call-up, Red Sox third basemen combined for -0.5 fWAR in 2017. Since Devers made his debut, he has hit .305/.368/.525 with 8 HR. His 1.0 fWAR is likely at least one win more than whatever the Sox would have trudged out there otherwise. With the Red Sox not having a huge lead in the AL East, the value of those extra wins cannot be understated.

As of this writing, Devers has 155 PA. If we roughly split that in half, we see what looks like two different hitters.

In his first 77 plate appearances, Devers was one of the best hitters in baseball. In his last 78 plate appearances, he was well below average. Now on the surface this might look like an arbitrary splitting of endpoints, and these PA numbers barely surpass Voros’s Law. However, there are some significant differences if we dig a little deeper.

It should come as a surprise to no one that a .400 BABIP and 35.3 percent HR/FB were never going to last. What is particularly interesting is that a player who went opposite field as much as Devers did also had a .667 SLG. It is even stranger when you consider the fact that he also had a 53 percent groundball rate and 33 percent flyball rate. His latter half BABIP and HR/FB look pretty reasonable, but it is also strange that his hard-hit rate went down when he primarily became a pull hitter. Now let’s take a look at the plate discipline numbers.

It can be good to be more aggressive in the strike zone, but Devers is combining that with lower contact rates in the zone. This is pure speculation, but it is possible that Devers started pressing more when he started struggling. If that is true, it is likely just growing pains that a talented hitter like Devers will get over.

The Red Sox are on a dangerous path toward disappointment

Winslow Townson-USA TODAY Sports

It’s not just the socks that are red in Boston; there are some serious red flags about their pitching staff, too.

Of all the bizarre facts I have shared about Devers so far, what might be the strangest of all is how he has hit against left-handed pitching so far. It is down right comical. He has hit .457/.513/.686 with a .667 BABIP in the minuscule sample of 39 PA. I hope that I do not have to convince anyone that his massive reverse splits after 155 PA are not real. If I were to guess, I would say that his current .505 wOBA against left-handed pitching is approximately 200 points higher than his true talent.

In this two-half split I have created, it is important to take a look at how pitchers might have changed their approach to Devers. Baseball is a game of constantly having to adapt, and that could explain Devers’s drop in offense. After all, there have been countless rookies in the history of baseball who came out of the gate firing, but then turned into a bust because of a failure to adjust and adapt. The aforementioned Will Middlebrooks fits this description.

Since Devers has barely faced left-handed pitching, I am going to just focus on how right-handed pitchers have adjusted against him. Let’s see what Brooks Baseball has to say about this.

Devers started seeing half as many sinkers, a third as many curveballs, and more sliders and fourseamers. Digging deeper, there does not seem to be much insight to be gained from the change in the percentage of sinkers seen by Devers.

What is interesting is that he went off on curveballs in his first half by hitting .364 with a .727 SLG, so that might be why he started to see them less often. But he did whiff on the pitch at about a 27 percent rate. He had more success making contact against the pitch in his second half, but he has only seen the pitch 12 times.

Devers raked against fourseamers by hitting .412 with a 1.000 SLG and 3 HR. My only explanation as to why teams decided to throw even more fourseamers is because they believed it to be the right strategy, that perhaps his previous success was just luck. He did have a .400 BABIP was whiffing at a 21 percent rate to start off with. Since the beginning of the second half of the split I created, Devers has whiffed at a 30 percent rate against fourseamers while hitting only .143 with a .333 SLG.

Something similarly can be said about the sliders. He never saw many of them to start and he never whiffed against a slider, but the total of his production against the pitch amounted to just one single. It appears that opposing pitchers decided to stay with it, and to much more success. In his second half of plate appearances, he has a 24 percent whiff rate, a .182 AVG, and a .273 SLG.

It should come as no surprise that opposite-handed pitchers are going to want to attack Devers with a changeup. I will do away with my splits for this one. For the season, Devers is hitting .286 against changeups, but with significant caveats. That batting average comes with a 27 percent whiff rate and only one extra base hit, a double.

Devers is just starting, of course, and 155 plate appearances are not a lot to go on. Still, it is interesting to see how Devers and his opposition have adjusted to each other. I am sure that any professional talent evaluator will tell you that he has the talent to continue to grow, learn, and adjust. The Red Sox will be set at third base for a long time.