J.D. Martinez is doing the hard work for opposing pitchers

In recent weeks, we’ve talked a fair bit about lineup optimization, both in respect to where the best hitters are physically batting in the lineup and what Kyle Schwarber and his patient approach can do for that optimization. But the fact of the matter, as many have correctly pointed out, is that it doesn’t much matter where the best hitters are slotted in the lineup if they aren’t, ya know, hitting. And right now they’re not hitting. We’re seeing collective slumps from some of the best bats in the lineup, and the result is low-scoring affairs and squandered chances in important spots. Wednesday’s ninth inning would be a prime example of the latter.

To me, right now the most frustration is stemming from the play of J.D. Martinez. The Red Sox slugger has not been much of a slugger in the second half, and has been particularly brutal more recently. When he’s on, he seems like a robot designed specifically for hitting the crap out of baseballs, with his mechanics meticulously put into place and his pitch recognition off the charts. The best quality to me when Martinez is hitting at his best is that he essentially never helps the pitcher. It seems straight forward, but it is perhaps the most important aspect of hitting. Right now he’s doing all the work for the opposing pitchers.

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Basically coming right out of the All-Star break, Martinez has just not looked like himself. After earning a spot on the American League roster for this year’s All-Star Game thanks to a 145 wRC+ in the first half, the mark has fallen by a whopping 56 points in the second half. Obviously the sample is much smaller — 366 plate appearances compared to 141 — but there are very concerning signs, not the least of which is his walk rate. That number has fallen from 10.1 percent in the first half — well above-average — to 5.7 percent since, which is well below-average. And this is indicative of that idea of helping out the opponent, and extends to the rest of the issues he’s displayed since the break.

When we do talk about a batter helping out the pitcher, almost always it’s about expanding the strike zone and swinging at bad pitches. There are other ways to do it, but that’s the most common and potentially most deadly way. Martinez has typically always shown a strong understanding of the zone and only expands when he’s behind or he can drive a pitch, but he’s been chasing much more often lately. Below you’ll see a graph of every five-game stretch for Martinez this season and what his O-Swing rate (i.e. the rate of pitches out of the zone that have induced swings) has been in those stretches.

There have certainly been some spikes throughout this season, which would presumably be the case for most any hitter. But for Martinez, there has been a prolonged spike somewhere around Game 90 on the graph, and specifically starting on July 19. Since that date, he hasn’t had a rate of swings on pitches out of the zone lower than 38.5 percent, which can be compared to the league-average rate of 31 percent. (The dotted line is his season rate, which sits at 38 percent.)

There’s no singular reason why Martinez is suddenly starting to expand the zone. In the simplest terms, it’s likely a combination of pressing due to mounting pressure stemming from the team’s recent performance and the way pitchers are approaching him. Looking at Baseball Savant, in August in particular he is being peppered with more breaking balls than he had been most of the summer, with that rate jumping to 38 percent. It had hovered around 30 percent for most of this season. In fact, this is the highest rate Martinez has seen of breaking balls in any given month since June of 2017.

The numbers against breaking balls this month, to be fair, are not totally out of line with what he’s done all season — he’s actually making a bit more contact and has better expected numbers compared to the previous couple of months — but it does help explain this zone expansion. Below you’ll see a comparison of pitches he was swinging at prior to July 19 and since July 19, and the biggest increase in swings on those pitches out of the zone are coming on balls down in away. That, of course, is where pitchers are typically trying to throw their breaking pitches.

These issues are obviously affecting that aforementioned walk rate, but it’s creeping into some of the batted ball issues as well. Martinez is also suffering from a relative lack of power in the second half, with his Isolated Power (SLG - AVG) falling from .256 in the first half to .189 since the break. Strangely, it’s not that he’s hitting the ball hard any less often — his hard-hit rate has fallen by less than a percentage point — but that he’s going the other way.

And while that is typically not an issue for Martinez, who has some of the best opposite-field power, he hasn’t been squaring these balls up. In the first half he hit about a third of his batted balls the other way hard (i.e. over 95 mph off the bat), but that rate is below a quarter of the time since the break. And considering the pitches at which he is offering, it’s not hard to see why he’s having trouble squaring up these balls and making solid contact.

As we eluded to above, this could certainly be a case of a guy trying to do too much. That would be speculation, but it’d make a whole lot of sense given both the performance of the team and himself. And these bad swings are both leading to weak contact, and also causing him to fall behind in counts, which in turn results in more weak contact and fewer walks. This Red Sox lineup has a really hard time of playing to its potential without Martinez at his best, and given how crucial these next few weeks are for the season, they need their All-Star DH to get back to his typical approach and stop providing free assistance for his opponents.