In 2015 and ’16, he slugged a paltry .347 against four-seam fastballs in the upper upper third and above the zone.
But that hole in Martinez’s swing is gone this season.
Martinez adjusted and raised his slugging percentage to .500 against fastballs in the upper third and above the zone in 2017 when he became aware of the counterpunch that pitchers were throwing at him with the four-seam spin. Martinez slugged .584 against fastballs in the same location this season.
That’s not the only change Martinez has made.
His pull percentage is also at its lowest level (at 37.7 percent) since he was an Astro in 2013. Out of 360 qualified hitters, Martinez ranked 268th this year despite playing in a home park with some of the most favorable left-field dimensions for a right-handed hitter.
Source: Travis Sawchik, FiveThirtyEight.com