One Big Question: Can J.D. Martinez shore up his plate discipline?

Welcome to the annual Over The Monster One Big Question season preview series. Over the next 40(ish) days, we will be running through every player on the Boston Red Sox 40-man roster and identifying a key question for them pertaining to the coming season. We will go through the roster in alphabetical order. For the most part, these will run Monday through Friday every week running up to the week before Opening Day, at least as things are scheduled right now. Obviously, the lockout may change the timing of the season, and it also means we will likely see more additions of new faces. If need be, we will add some weekend posts to fit any and all additions to the 40-man before Opening Day. You can catch up with every post by following this link. With that, today we cover J.D. Martinez.

The Question: Can J.D. Martinez get his plate discipline back up above average?

As we sit here on Tuesday morning shortly before the players and owners are set to meet again after a long night of discussions on Monday, we have no idea if spring training is going to start in days or weeks or months. There is optimism, but still plenty of unknown. One of the things we do know about this new CBA that’s coming up is that it’ll include a universal DH, adding the lineup spot to National League rosters. As we’ve written about, that may affect the Red Sox, who have J.D. Martinez in that position now and may have eyes for Kyle Schwarber. It remains to be seen if they actually would swing a deal involving Martinez as we’ve talked about before, but it remains a possibility at the very least. But wherever he ends up, Martinez still has the skillset to be an impact, middle-of-the-order bat and to transform a lineup.

Last season was a fascinating one heading into the year, with Martinez coming off a rough 2020 that was easy to write off for multiple reasons, perhaps most notably due to the lack of video available to players that season and how much he relies on that between at bats. So it was good to see him rebound to some extent in 2021, finishing the year hitting .286/.349/.518 for a 128 wRC+ that put him 28 percent better than league-average by that metric. It wasn’t a rebound to his 2018, which is one of the better offensive seasons from a Red Sox player in recent memory, or even 2019, but there were positive strides made in relation to the 2020 season.

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Most notable was that he was hitting for power again, something that was weirdly lacking in that 2020 campaign. That year, Martinez finished with an Isolated Power (SLG - AVG) below .200, the only time he’s done that since 2013. The veteran finished last season in the top 10 percent of baseball in both hard-hit rate and average exit velocity (per Baseball Savant) and finished with 28 homers and a .232 ISO. Again, he’s not matching his peak production, but in his age-33 season that wasn’t the expectation. The power was where the Red Sox needed it, and he used that hard contact to convert plenty of batted balls into hits as well, finishing with a .340 batting average on balls in play.

In fact, those numbers weren’t really all that far off from that 2019 season in which he finished with a 139 wRC+, and the power may actually be more impressive given the situation with the physical baseballs that season. So why was he still 11 points behind in wRC+? That would come down to his plate discipline, which in turn becomes the key thing to watch with the veteran slugger as we look ahead to 2022.

Looking at the numbers from Martinez last season, it’s the strikeouts and walks that really stand out the most. Granted, he has never really been elite at avoiding strikeouts, but in his first two seasons with the Red Sox he cut that rate down below 23 percent, but has been above that number, even marginally, the last two seasons. Meanwhile, his walk rate has really taken a hit, going from around 11 percent every year from 2016-2019 down to 8.7 percent this past season, his lowest mark since 2015. Again, Martinez was more than fine in 2021 so we’re picking nits a bit, but at the same time as a DH he needs his bat to be at its maximum potential. If he’s only walking and striking out at league-average rates (or a tad worse in the case of strikeouts), then he’s not at that maximum potential.

If we dig a little bit deeper into these issues, it’s clear it’s coming down not to an issue of failing to make contact, but rather swinging at the wrong pitches. Looking at Baseball Savant’s data, Martinez over a third of the pitches out of the strike zone he saw last season, the highest rate of his career by a fairly significant margin. He is actually making just as much contact as he has before, but of course when you’re just swinging more in the aggregate the rate of strikeouts is going to come up, not to mention the lack of walks that comes with swinging at balls.

Below you can see a comparison of the pitches Martinez swung at in 2021 compared to 2019, when he walked 11 percent of the time with a 21 percent strikeout rate.

That couldn’t be more clear. It’s pitches in on the hands, off the inside corner, that Martinez is having trouble laying off. Again, contact on these pitches wasn’t an issue relative to 2019, with the margin for those two zones varying only by a percentage point in the upper zone and two percentage points in the lower. But these are pitches that he had been able to lay off in the past to work counts and get on base, but now are probably more often turning into pop ups or ground balls. His average exit velocity in these zones were 79 mph at the top and 89 mph at the bottom.

Martinez was once again one of the best bats in the Red Sox lineup last season, putting aside any concerns that may have popped up after that tough 2020 season. But there is still another level for him to come back to, and it’s not about making better contact, or even making more contact, both of which could be a sign of aging. Instead, it’s just better pitch recognition and better discipline to lay off bad pitches, particularly in on the hands. If he can do that, in whatever lineup he ends up, he’ll be back to truly being one of the elite bats in the game rather than simply a very, very good one.

Statistics in this post from FanGraphs and Baseball Savant.