JD Martinez, Constantly Evolving

Clip art illustration of a Cartoon Tiger with a Missing Tooth

If you’re reading this website you’re familiar with the JD Martinez breakout. He remade his swing between 2013 and 2014 and he started hitting the ball much harder. That led to more hits and more power. Instead of being a below average hitter, he became one of the best dozen hitters in the league.

Given his low walk, high strikeout profile, we spent much of 2014 holding our breath. Guys who slug like Martinez without great discipline are frequently exploitable. We waited for the exploitation and it didn’t come. And when Martinez picked up where he left off in 2015 and had another great season, the white-knuckling stopped. JD Martinez, Actually Good!

From a results standpoint, his 2016 season has been a little worse. Instead of the 140-150 wRC+ range, Martinez is in the 120-130 neighborhood. That drop would be more concerning if we were more than 100 PA into the season, but even if you’re someone who overreacts, Martinez is still hitting well, even if he isn’t hitting like an MVP candidate.

What’s interesting about Martinez in 2016, however, is that he’s striking out much less often while also walking more. Here are some numbers (everything entering Sunday).

Screenshot 2016-05-01 at 3.50.40 PM

The better BB% and K% is encouraging. A walk is better than a ball in play and a ball in play is better than a strikeout, so any time you can add walks and cut strikeouts, you’re in good shape. And while 100 PA is just 100 PA, the better discipline results are supported by his lower swing rate.

Screenshot 2016-05-01 at 3.55.33 PM

Pitchers are challenging him with fewer pitches in the zone, and Martinez is swinging less often, particularly on pitches outside the strikezone. In other words, the Martinez isn’t swinging at the pitches that used to be in the zone but are now outside the zone.

You can get a sense here graphically:


All things being equal, more walks and fewer strikeouts is good. The only concern you might have is that this less aggressive approach is cutting down on his power. His ISO is down a non-trivial amount. Is that just small sample fluctuation or is he actually hitting the ball more softly?

Using Statcast Exit Velocity, Martinez is averaging 91.5 mph this year off the bat after a 91.8 mph average in 2015. That’s basically nothing, but contact quality is also about the angle at which the ball is hit. Hitting it 92 mph into the ground is different than on a line and different than in the air.


It’s obviously a much smaller number of balls in play for 2016, but the general shape of the chart looks the same. We could run an expected ISO using the Statcast data, but it looks to me like he’s probably just hit a few more ground balls this year when he would have otherwise elevated them last year. He’s averaging a launch angle of around 15 degrees this year when it was 16 last year. Could this be a minor problem that is costing him a little power? Sure, but it’s way to early to think it’s anything more than normal batted ball variance.

As with everything, it’s early. But pitchers are being more cautious with Martinez this season and Martinez appears to be adapting by taking more pitches. As long as it’s not sapping his power, this is going to wind up being a boon to his overall numbers and his ability to age gracefully.


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