J.D. Martinez Finds His Stroke

I remember walking into a Phoenix area bar to meet my FanGraphs colleagues last spring. It was a convergence of baseball nerdery rivaled only by the SABR conference across town. Someone started talking about J.D. Martinez. He had changed his swing over the offseason and could tap into his latent power with a clean, easy stroke. The Astros were going to be pleasantly surprised.

It turned out that the Astros had already moved on internally. They weren’t willing to give Martinez another shot, but they were nice enough to grant his release rather than force him to drown at the bottom of the depth chart. And that’s how he latched on with the Tigers.

Detroit was seemingly a weird landing spot for Martinez. They’re a first division club and at the time they had plenty of right-handed hitting outfielders. Martinez was buried after all, but he got his chances. By making good on them time and time again, he’s opened the door to a regular role in 2015.

Let’s start with what he did. Per Zach Sanders, he provided $18 of value in two-thirds of a season. In 480 plate appearances, he posted a 57/23/76/6/.315 fantasy line while hitting behind Miguel Cabrera and Victor Martinez. He’ll be similarly blessed next season. His .238 ISO was the 12th best in the league among hitters with over 450 plate appearances. His 153 wRC+ was tied ninth, with Anthony Rizzo.

His mechanical change makes it difficult to handicap regression in some cases. Should we expect his 19.5 percent HR/FB ratio to regress? Probably, but I think it will remain impressive. His average fly ball distance of 299 feet supports a high HR/FB ratio.

Similarly, his .389 BABIP is due for correction, but perhaps not as much as you would expect from a power hitter. Martinez isn’t slow and he hit the ball with authority this season, both of which help BABIP. His infield fly ball rate was a career low 2.5 percent. I can’t tell you if that’s a fluke, the result of his new mechanics, or a combination of the two. Avoiding those free outs while continuing to make impressive contact should allow for a BABIP in the .330’s range. Even Steamer is calling for a .327 BABIP.

If there’s an area of concern, it’s his plate discipline. He swings 10 percent more often than the average hitter, yet he whiffs seven percent more frequently. A high 15.2 percent whiff rate explains both factors. If you’re the kind of hitter who swings through pitches, it behooves you to seek early count outcomes. Martinez did post a career best 6.3 percent walk rate, which is only about one percent below league average. His strikeout rate was six percent above average. Like with Chris Carter, if Martinez gets in a funk, his whifftastic tendencies could lead to some ugly outcomes.

As you’ll see in the results and averages shown below, Martinez’s weakness is offspeed pitches. He’s always done well recognizing breaking balls, which is something that most high strikeout power hitters cannot say.

In the infield, he’s potentially shiftable. Instead of a full shift, the third baseman and shortstop can be swung towards the line slightly since he doesn’t hit too many grounders up the middle. The outfield component of his spray chart should be reassuring for fantasy owners. He used all fields and distributed his home runs evenly.

As for expectations, we should always plan for regression after an unusual season. Martinez seems likely to hit for less power and batting average. Steamer says a 67/21/75/5/.273 line in 549 plate appearances is a good bet. I think we’ll see more power than that, with a chance at 30 home runs. His RBI totals should remain strong with two OBP threats ahead of him in the lineup. I won’t outright disagree with the 549 plate appearance estimate, but I do think he’ll exceed it unless he spends time on the disable list. The end result sounds similar to Matt Holliday. He was worth $20 this season.