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A Detailed Look at J.D. Martinez

"Is J.D. Martinez the promising slugger whose dynamic performance in the minor leagues indicated that he was a diamond in the tar pits of the Astros’ farm clubs? Or will he continue to slip on the ice of the major leagues to land unceremoniously on his rear?"

Bob Levey

At age 24, Hunter Pence broke into the big leagues. In 2011, J.D. Martinez made his major league debut, a full year younger than Pence was in his Rookie season. By age 24, Martinez was one of the most tenured members of the club and was expected to build on early success with a breakout season. Unfortunately, fans have begun to turn on him after a struggle-laden performance that saw him demoted to the minors for a month in mid-2012.

Lest we forget, Martinez had defied the scouts and slugged his way into the Astros’ attention by hitting .302/.357/.407 at AA Corpus Christi in 2010, followed by a blistering .338/.414/.546 performance at the same level in 2011. Once he reached the majors that season, he batted a modest .274/.319/.423, but that was at the tender age of 23. In 2012, the training wheels came off, but Martinez hit only .241/.311/.375, which included two months in which his average dropped below .200.

Is J.D. Martinez the promising slugger whose dynamic performance in the minor leagues indicated that he was a diamond in the tar pits of the Astros’ farm clubs? Or will he continue to slip on the ice of the major leagues to land unceremoniously on his rear?

Initial Thoughts:

Positives: Certain stats stand out when comparing Martinez’ major league seasons. His Strikeout Rate has stayed constant between 21 and 22 percent, an acceptable figure for a major leaguer. His walk rate has increased from 5.8% to 9.1%. On the surface, this indicates a more patient approach than he showed in 2011. Likewise, his contact rate has also risen, to 78.2%. A decrease in his Swing Rate (by 6 points!) shows that Martinez learned to wait for the pitch he wanted this season. On pitches outside the zone, he lowered his swing rate by 6% (29.3%), while increasing his contact rate against those pitches he did decide to chase. Finally, Martinez was much more "clutchy", increasing his Fangraph’s Clutch score from .11 to .71; he hit .306 in high leverage situations in 2012.

Negatives: For some reason, Martinez’ patient approach in 2012 just did not work. His ISO (Isolated Power = Total Bases per At-Bat minus singles per At Bat) dropped even though his Home Run per Fly Ball rate increased. This drop in power is partially because he hit the same number of doubles in twice the number of Plate Appearances, but mostly because his Fly Ball and Line Drive Rates drastically decreased while his Ground Ball rate increased by 15%. Over half of the balls Martinez put into play in 2012 were ground balls, up from about 37% in 2011. Lastly, Martinez may be suffering from a decreased Batting Average on Balls in Play (BABIP). Though his 2011 BABIP (.325) isn’t unsustainably high, 2012’s lower .290 certainly helped suppress his counting stats.

Pitcher Approach:

MLB Gameday’s Pitch F/X system indicates that pitchers varied little in the selection of pitch types they hurled to Martinez in 2012 compared to 2011 1-jdpitchtype_medium

Left Handed Pitchers (LHPs) are still pounding him with changeups and two-seam fastballs about 50% of the time. As a right handed batter, the two-seamers will tail away from Martinez to create weak contact or a swing-and-miss. Right Handed Pitchers (RHPs) have not varied their approach to Martinez except for a slight uptick in the number of pitches that Pitch F/X classifies as sinkers. Either Martinez faced more sinkerball pitchers this season or else Pitch F/X confused the pitches with other downward-driving pitches like sliders and well-aimed fastballs.

Pitchers are showing an increased effort to generate ground balls through location against Martinez. The percentage of pitches thrown "down and away" has increased slightly but not alarmingly. However, the number of pitches thrown directly below the zone has increased to 37%. In 2012, Almost four out of every ten pitches thrown to Martinez in 2012 were over the plate, but below the strike zone.

Graphing each pitch shows that this approach of throwing as many pitches as possible around the bottom of the strike zone is generating negative results for Martinez. The following graphs show the "Negative Outcomes" that Martinez incurred on pitches for 2011 and 2012, to display how pitchers have attacked him to achieve their success.



In both graphs, there is a normal-looking distribution for a young hitter; which is to say that his whiffs trend toward the "down and away" pitches, while his called strikes are dispersed all around with a very slight favoring of the "down and away" zone. The interesting thing is when the out-generating pitches are compared. In 2011, the "In Play, Out" pitches are distributed evenly (more or less) around the strike zone. But in 2012, out pitches trend a bit towards the "down and away" zone, which indicates pitchers have had more success getting Martinez to hit into an out through location of their arsenals.

The Strike Zone

The most interesting data from Pitch F/X is the strike zone itself. Pitch F/X uses video to measure the top and bottom of the strike zone, where the top is four inches above the belt and the bottom is the hollow of the knee. Assuming the method for calculating a player’s strike zone on each pitch is consistent between 2011 and 2012, Martinez’ strike zone actually expanded vertically by 1.34", or half the width of a baseball. This is significant because a larger strike zone gives the pitcher the advantage—they have more area in which to locate their pitches and perhaps get away with more borderline calls. Martinez’ expanded strike zone could be the result of a more upright, but wider stance, though the difference is so relatively minor (to his height) that it is hard to suggest the change is intentional. In fact, one wonders if the change is due to favoring weak knees, as he has been known to struggle with knee issues in the past. Regardless, if Pitch F/X is not making a mistake, then Martinez’ stance change has helped to tip the scales in the pitchers’ favor.

2011 SZ Top = 3.58 ft.
2011 SZ Bot = 1.75 ft.

2012 SZ Top = 3.65 ft.
2012 SZ Bot = 1.70 ft.

Hit Track

The hit tracker shows that there has been little difference in the directions of balls Martinez puts into play. He is a slight pull hitter, though less so in 2012 (52% of balls in play to the left side of the field in 2012 versus 57% in 2011). This is primarily due to--believe it or not--a lower tendency to pull pitches thrown by LHP’s. One would think that just because of physics, a right-handed hitter would be more likely to bonk a LHP’s pitch to the opposite field, but in 2011, Martinez was a 60% pull hitter. That may be a small sample error though, as he only put 40 balls in play against LHP’s in 2011.


5-jd2012jdhits_medium \

Actually looking at the locations of the hits and outs is illustrative:



In one sense, the graphics above reinforce the point that Martinez has been better at using all fields in 2012 than in 2011. In the long-term this will benefit him. However, the 2012 chart shows that an increasing percentage of outs have been ground ball outs. This also agrees with the hit data above that reports a whopping 10% increase in the number of groundball outs. Almost 40% of the balls Martinez puts into play turn into ground ball outs, a figure that is incompatible with major league success.


So what about BABIP, or Batting Average on Balls in Play? The gist of BABIP is "how many of the balls the player puts into the field of play (i.e. those he makes contact with that are not fouled into the stands) actually fall for hits?"

In the minors, Martinez has never posted a BABIP below .353 (excluding a short stint in 2012), and his average is actually around .380. This is an astronomically high figure and won’t translate to the major leagues, but the takeaway here is that Martinez is a guy who should be able to sustain a BABIP in the majors that is above league-average. His .325 in 2011 does not seem unreasonable with that backdrop.

However, for whatever reason (more ground balls, better defensive opponents, bad luck), Martinez’ dropped to a BABIP of .290. .290 is close to league average but low for Martinez.

Martinez’ 2012 HR/FB rate was about the same as 2011, his K% is about the same, and the sac fly number is so small it hardly counts. So the only thing that can significantly impact his BABIP is the number of walks he’s taking (decreasing his At Bats with respect to Plate Appearances) and the number of hits that fall.

If Martinez had the same BABIP in 2012 as he had in 2011, and everything stayed constant except for the number of hits (a not unreasonable qualifier to put on this experiment), Martinez would have logged 105 hits instead of 95. His .266 batting average would have looked more acceptable, and it’s reasonable to expect that a few of those would have gone for extra bases. Given that, wouldn't Astros fans be happier with a .266/.330/.410 slash line from their 24-year-old Left Fielder in 2012?


With the information above, I conclude that Martinez should be given another legitimate shot at holding down the full-time Left Field job for the 2013 Astros. His statistics improved in many places, namely contact rate and walk rate, and some of the numbers indicate that he perhaps should have been more successful than he actually was last season.

His struggles in 2012 appear to be the result of pitch location by opponents compounded by a slightly taller strike zone, plus a BABIP that is well below his career values. All of these issues have resulted in a sky-high groundball rate that led to a lower rate of successful outcomes overall.

The issues are correctable by examining a ton of video to see if his stance has changed to increase the strike zone size, by laying off of more pitches down and away in the zone in situations where there are not two strikes, working fouling off pitches in that quadrant of the strike zone, and by a return to normalcy of his BABIP.