Last month, our JJ Keller asked whether new Seattle Mariner Jean Segura is “for real”. It was a question worth asking, because Segura was coming off a 5.0-fWAR season, by far the best of his five MLB seasons, and he was joining a team banking on him to be a solid producer at a valuable position. To try to figure out whether the Mariners really were bringing a player with true five-win talent aboard, JJ took a look under the hood and discovered “a sharp decline in his chase rate, as well as a jump in his hard-hit rate,” two things that certainly portend well for Segura’s ability to follow up on his 2016 offensive spike this season. JJ’s analysis of comparable players — based on chase, contact, and hard-hit rates — wasn’t particularly encouraging for Segura’s 2017 outlook, but there’s something else afoot; we just need to look a little deeper.

If improved plate discipline and contact quality drove Segura’s offensive breakout last year, it’s worth asking how he managed to make those improvements. Courtesy of this close inspection at Beyond The Box Score, we know that Segura spent the 2015-16 offseason reworking his swing, primarily by bringing the starting position of his hands down from his head toward the middle of his body. The effect was a reduction in swing motion, an increase in decision time, and, it appears, an increase in launch angle.

Like others who have altered their swing mechanics, including J.D. Martinez and Daniel Murphy, the results were tremendous.

How has Segura followed up on his 2016 metamorphosis? The short answer: pretty well. It doesn’t, but if the season ended today, he already would have produced a more valuable season in just ten games (0.7 fWAR) than he did in 143 games in 2015 (0.3 fWAR).* Rather than resting on his laurels and passively enjoying the bounty of his new swing, Segura appears to be trying to push the envelope further in 2017 with a more aggressive approach at the plate.

On Tuesday, the Mariners and Tigers played a silly game of baseball in Detroit that included forty total hits, twenty-eight total runs scored, and, miraculously, no official errors recorded, all in regulation time. While the Tigers ended up outpointing the Mariners 19-9, it was Segura who got things started by lacing the very first pitch of the game to left field for a single, coming around to score soon after on a Nelson Cruz sacrifice fly later in the inning. Segura has swung at 31.9% of the first pitches he’s seen this year, a rate that would place him just inside the top seventy qualified hitters if he had enough plate appearances to qualify. It isn’t a rate that’s remarkable when compared to his peers, but it is a noticeable increase over his 2016 first-pitch swing rate (24.0%) and his career average entering this season (27.6%).

First-pitch swing rate, alone, isn’t the most illuminating indicator of a batter’s approach, but it’s not nothing, and it fits within a broader constellation of data points that illustrate a picture of Segura as a more aggressive hitter than he’s been in the past. Segura is swinging more, and almost all of those additional swings are coming on pitches in the strike zone. His overall swing rate thus far is 51.1%, up about five points from last year, and while his swing rate on pitches out of the zone has held steady at 33.0%, his in-zone swing rate has spiked to 73.4%, easily a career high, and nearly ten points higher than in 2016. The combination of discipline and aggression has buoyed Segura to a 165 wRC+, a mark that, by far, would be the best of his career.

Segura already has missed time in this young season with a hamstring injury, so that will be something to watch as his first season in Seattle progresses. So too will be his plate approach which, from what limited indicia we have at this time, appears to be increasingly aggressive as he settles into his second season with his reworked swing. (Another thing to watch, so long as we’re listing things to watch, is how opponents are pitching to him. He’s always seen a lot of pitches in the zone, and that looks to be holding true so far this season, but pitchers may adjust if Segura keeps punishing them the way he did last year.)  If Segura can add aggression to his offensive game while maintaining his zone discipline, he has the potential to prove that his 2016 breakout was real, and he even may build upon it. If he can do that, he would force his name into the suddenly robust list of excellent young American League shortstops.

* All cited statistics are current through April 26, 2017.

More of AD’s work may be found at ALDLAND.