There are a lot of reasons why the Oakland A’s are bound for the playoffs this year. Matt Chapman has produced an MVP-level season, and the club’s bullpen is amazing. Khris Davis, Jed Lowrie, Matt Olson, and Marcus Semien are all having good years, as well.

Unsurprisingly, playoff teams tend to be composed of good players. All of the individuals mentioned so far, however, were also members of a club that won just 75 games a year ago. Their strong play this season has undoubtedly helped the 2018 version of the A’s, but the club has also gotten an important contribution from newcomer Stephen Piscotty.

The right fielder joined Oakland in a winter trade from the St. Louis following a difficult year and a half for him both on the field and off. Despite playing well following his call-up in the middle of 2015 until the All-Star break in 2016, Piscotty’s performance suffered after that. Off the field, Piscotty contended with an infinitely worse blow when his mother, Gretchen, was diagnosed with ALS in May 2017.

Piscotty took some time off that season to be with his family. On the field, he dealt with multiple DL stints and a trip to the minors. It’s hard, if not impossible, to understand what Piscotty was going through. One gets a sense of it, though, from Susan Slusser’s profile of the outfielder published this past May:

“It’s relatively hard to watch, to see the progression take place… I feel so bad. I want to put a positive spin on it, but there are things that are out of our control and we’re just trying to make the best of a bad situation, and hopefully with what we’re doing, we can one day get to a point where other folks don’t have to go through it.”

The trade to the A’s wasn’t a panacea. Piscotty continued to slump at the beginning of the season. His mother died in early May and Piscotty hit an emotional home run in his first game back.

A few weeks later, though, Oakland was still hovering around .500. At that point, Piscotty had reached base just six times in his 35 plate appearances after the homer. There was little indication that, over the next four months, Piscotty would be one of the best hitters in all of baseball. As the table below demonstrates, though, that’s precisely what happened.

Among the collection of players included here, we find a bunch of MVP candidates, some former MVPs, two of the top-three home-run hitters since the start of 2016… and Stephen Piscotty. Since June 13, the only player in the AL who’s hit more homers than Piscotty’s 23 is his own teammate, Khris Davis, who’s recorded 28 in that same timeframe. Among all players, Matt Carpenter (28), Rhys Hoskins (25), and Christian Yelich (24) are the only players who have hit more home runs than Piscotty over the last three-and-a-half months.Of the players in the table above, Piscotty’s walk rate is comfortably the lowest. That might not be a great indicator that he will maintain his current levels, but it does more closely represent the player he was when he first reached the majors and had success.

Entering the 2015 season, Piscotty was well regarded as a prospect for his ability to put bat to ball, even if his power had yet to translate to games in two-and-a-half minor-league seasons. Piscotty had a defensive profile for a corner-outfield spot, but a .143 ISO in the minors — including just a .118 figure in a full season of Triple-A in 2014 — didn’t necessarily indicate the sort of power typical of that position. Scouts thought there was more to the stat line. Kiley McDaniel wrote that “the raw power is there for 20 homers, which would make him a middle of the order type bat.” That was written back when 20 homers would put you in the top quarter of hitters instead of just the top half, like now, but there was power in practice that was untapped at the time.

Ahead of the 2015 season, Piscotty worked to tap into the power, as he told Eno Sarris later that year:

“In the offseason I made an attempt to tap into more power, that was a big offseason goal,” the outfielder said before a game with the Giants. In order to do that, the outfielder tried to get a “flatter bat path, not so much down to the ball.” The elbows turned out to be a big key. “I worked on getting my back elbow a little closer to my body to get more extension. The whole thing was about getting more extension.”

His work paid off. He hit double-digit homers in a half-season of Triple-A and 20 more in a full season after his promotion. He made the Cardinals look smart for failing to re-sign Jason Heyward, and even after Piscotty’s disappointing second half, the team signed him to a long-term deal, guaranteeing him $33 million. After a lost season in 2017 and a poor start to 2018, however, Piscotty had spent more time being a poor hitter than a good one. Selectively choosing endpoints, his career looks a bit like this.

Stephen Piscotty Career Arc Date PA HR BB% K% ISO BABIP AVG OBP SLG wRC+ 7/21/15 to 7/20/16 638 20 8.5 % 19.1 % .191 .349 .299 .365 .490 133 7/21/16 to 5/27/18 841 21 9.4 % 22.4 % .141 .283 .234 .317 .375 87 5/28/18 to 9/23/18 414 23 6.8 % 17.9 % .269 .307 .291 .353 .560 149

Here’s the same information, graphically:

I mentioned Piscotty’s low walk rate earlier. While failing to draw walks isn’t a good thing in isolation, Piscotty had pretty clearly become too passive in the middle part of his career. He was seeing more pitches and striking out more. He was walking more, as well, but the exchange was counterproductive. He ended a relatively high percentage of plate appearances with two strikes, and a lack of aggression in those situations took away his power. The table below shows the number of two-strike plate appearances as well as his performance in those appearances.

Stephen Piscotty With Two Strikes Date PA 2-Strike PA % of

2-Strike PA 2-Strike wRC+ Before 2-Strike wRC+ 7/21/15 to 7/20/16 638 327 51.3% 68 201 7/21/16 to 5/27/18 841 476 56.6% 54 130 5/28/18 to 9/23/18 414 200 48.3% 46 245

Piscotty’s performance with two strikes is close to the league-average of 45 wRC+, but his patient approach was putting him in more of those counts. We can see a change in Piscotty’s aggression looking at a rolling chart of swings out of the zone and contact out of the zone.

Piscotty’s controlled approach in 2017 led to fewer swings outside the zone and more contact outside the zone. That’s good for avoiding strikeouts, but it is bad for a batter who wants to hit the ball hard. This season, Piscotty is swinging at more balls out of the zone and is making contact less often. He’s whiffing on a lot of sliders and striking out on a lot of curves, as well. At the same time, though, he is absolutely crushing fastballs, producing a 202 wRC+ in plate appearances that end on the pitch this season. It’s possible pitchers will adjust and throw fewer fastballs. Then Piscotty will have to become more patient or end up with a lot more strikeouts. In the meantime, though, he’s busy being one of the best hitters in the game. After the last few years, it should be impossible not to root for him.