Jose MartinezZach Gifford | THE INTREPID STL

Photo Credit: @cardinalsgifs

Last September, Jose Martinez‘s call-up to St. Louis didn’t feel like much more than a good story. After a decade long minor league career, he was considered a non-prospect. After being acquired from the Royals for cash, he played uninspiring baseball. His .269/.326/.415 line in Memphis over 329 plate appearances was good for a mere 95 wRC+, or 5% below average for a AAA hitter. He looked just like a career minor leaguer who had spent his career in the minor leagues.

Upon his arrival in to the Major Leagues, though, Jose Martinez actually looked the part. He hit .438 and struck out only once in a very small sample covering 18 plate appearances. He passed the eye test as well, taking strong at-bats and hanging tough against the likes of Aroldis Chapman (this seven pitch at-bat should have at least gone an eighth).

Fast forward to this September, and not only has Martinez won a spot on the roster in Spring Training and carved out a role for himself in the Majors, he’s actually the second-best hitter on a team in playoff contention. It’s no accident, either – his 139 wRC+ ranks 25th among 304 players with at least 240 plate appearances. In fact, Statcast’s expected-wOBA suggests he’s even been unlucky.

Back in April, I wrote about how Martinez had bought into the air-ball revolution. I thought he possessed the raw talent to make such an approach work, given that he’d already shown the ability to generate hard contact (95+ mph) and good contact skill.

Thus far, that adjustment has worked. But Martinez has made another, more subtle adjustment this season. He’s being more selective at the plate.

Last season, Martinez swung at 36 of the 73 pitches he faced, or 49.3%. That’s a very small sample, but it’s all we have to work with from his 2016 campaign. This year we have a much larger sample, and Martinez is swinging at only 41.3% of pitches.

Keeping in mind the small sample size, I looked for all non-pitchers who made at least ten plate appearances in 2016 and 2017. I calculated the difference between everyone’s swing rate this year and last. Players with negative differentials are getting more patient, while players with positive differences are swinging more aggressively. Then I ranked them in ascending order so the hitters with the biggest changes favoring patience showed up first.

Among that group of 453 players, Martinez has the 16th largest drop in swing rate. Of the players with larger swing rate drops, only Hunter Renfroe, Brian Goodwin, and Jonathan Schoop have more plate appearances this year.

One result of swinging less has been a small bump to Martinez’s walk and strikeout rates compared to his minor league track record. But how has swinging less translated to batted ball success for Martinez? First, let’s look at his exit velocity heatmap by strike zone location:

Jose MartinezZach Gifford | THE INTREPID STL

And then his swings by location:

Jose MartinezZach Gifford | THE INTREPID STL

As you can see, the two heatmaps line up fairly well. Martinez likes the ball down in the zone, and he designed his uppercut swing to punish those pitches. Even on the inside and outside edges in the middle zone, his exit velocities (88.1 and 89.3 mph) are above league average; they’re only blue because they’re below his overall average exit velocity. Regardless, we can see that Martinez knows where pitches need to be for him to drive the ball and produce.

This refined approach is paying off in two distinct ways. First, when Martinez is ahead in the count, he’s literally the most dangerous hitter in baseball: his .587 wOBA when ahead in the count leads the league through September 11th.

Additionally, he isn’t afraid to get behind in the count while he waits for his pitch. Consider this at-bat against Matt Cain, with visuals courtesy of the great @cardinalsgifs:

Jose MartinezZach Gifford | THE INTREPID STL

Strike one is a tough first-pitch curve that most hitters would take. It’s strike two where Martinez shows his discipline. Cain paints the edge with a fastball in a location that induces a swing nearly 70% of the time and a resultant wOBA of only .249. By trusting his approach and his contact ability despite being in an 0-2 hole, Martinez lives to see another pitch. Cain then makes a mistake, and Martinez gets a pitch right in his sweet spot. The result isn’t all that impressive (although this single had an exit velocity of 101 mph), but it’s a base hit nonetheless. It got the inning going, and Martinez would eventually score on a Randal Grichuk home run.

Jose Martinez’s career would have been considered a success even if he just stuck on as a reserve outfielder. Yet, by making careful adjustments to how he swings and what he swings at, he’s become a legitimate middle-of-the-order option for a playoff-caliber team.