PITTSBURGH — Corey Dickerson had a weird offseason.

After being named an All-Star last year and finishing with an 115 wRC+, 27-homer, three-win campaign, Dickerson was designated for assignment by Tampa Bay in February. You don’t see that every day. The always cost-conscious Rays did not want to be on the hook for $5.9 million. The Pirates acquired him for Daniel Hudson, minor-league infielder Tristan Gray, and cash considerations. Perhaps the Rays were also concerned about Dickerson’s issues against the fastball.

Last season, no batter swung and missed at elevated fastballs more often than Dickerson. In an age when spin and “rise” are better understood than ever, perhaps the Rays thought Dickerson would be vulnerable to a general trend, to say nothing of specific scouting reports. Maybe the Rays felt this was an uncorrectable flaw. The club eventually acquired C.J. Cron, who offered roughly similar production at a cheaper price — without the same kind of weaknesses against the fastball.

Dickerson swung and missed at 102 of 291 total four-seamers in the upper third or above the zone last year, according to Baseball Savant data, a rate of 35.1%. Here is one of this occasions:

Against elevated fastballs this season, though? He’s whiffed just 14 times on 112 such pitches. That’s just 12.5% of them.

When offering at a four-seam fastballs last year, Dickerson whiffed at a 32.6% rate.

This season? A 14.1% rate.

In fact, Dickerson has enjoyed the greatest strikeout decline among batters with at least 500 plate appearances last year and 200 this season. And it’s not close:

While the Pirates’ outfield has become crowded with the call-up and impressive play of Austin Meadows, Dickerson has elevated his stock and carved out a future role in Pittsburgh (or perhaps elsewhere) with a remarkable 2018 transformation.

He’s cut his strikeout rate from 24.2% last year (21.4% career) to 11.3% this season. He enters play with a 120 wRC+, an improvement not only over last year but also his career average mark (120 wRC+).

After ranking among the worst high-fastball hitters in the game for multiple seasons, Dickerson has suddenly erased that weakness. Jeff Sullivan examined this trend in early May and Dickerson has since kept the gains.

When I covered the Pirates as a newspaperman, one of their philosophies when it came to prospects was that it was better to target a hit-tool first over power, the idea being that power could be more easily developed while bat-to-ball skills were more innate. What’s interesting is that Dickerson has dramatically improved his hit tool — and in short order.

In Pittsburgh last week, I asked Dickerson just how he pulled this off.

“It would get too deep for you,” said Dickerson, breaking into a grin before his locker.

Humor me, I pleaded.

“I’m all about change,” Dickerson said. “Looking at the analytics, I saw that I swung through a lot of fastballs… I kind of went to it myself. ‘How could I get better?’ It’s a trail… With how good my hand-eye [coordination] is, there’s no reason why I should take big cuts and miss those opportunities, because I have a really good two-strike approach.”

In seeing how much swing and miss he had against fastballs, Dickerson decided to trade in power for contact.

“What I used to do is swing real hard and foul off [or miss] a lot of fastballs,” Dickerson said. “I started thinking about how good of a hitter I am inside the zone… If I don’t foul off a lot of those fastballs, or pitches earlier in the count, how much better could I be? I found a way of shortening up. Choking up. I’ve never choked up in my career except a few times with two strikes here and there. Spreading out… Now I have a better chance to make contact earlier in count.”

Dickerson used to rarely choke up. Now he chokes up often in all counts:

Compare 2017…

… to 2018:

Dickerson also discussed how he “manipulates” his body.

“I hit in different stances,” Dickerson said. “I kind of spread put, or stand up, depending on the pitcher and the movement of his pitches.”

Consider Dickerson against ground-ball specialist Scott Alexander last week. Notice how he gets into more of a crouch:

Then consider Dickerson against Derek Holland, who is a fly-ball pitcher. Dickerson stands more upright.

The result of these adjustments is that Dickerson has come up empty far less often. Consider his contract-per-swing rate against fastballs.

In 2017…

… and 2018:

“I’m starting to take more pitches,” Dickerson said, “to be more selective outside the zone… I don’t think about homers. Maybe it’s risk vs. reward. Maybe my homers will go down, but my strikeouts will go down. My overall production is [improved], more contact.”

As Dickerson notes, the result might occasionally be more modest contact, but contact nonetheless:

And the data indicate that Dickerson certainly is swinging at fewer pitches above the zone, and out of the zone, compared to a year ago:

Here’s 2017:

And 2018:

Dickerson also studied video this offseason, looking at some of the game’s best hitters — Barry Bonds, Miguel Cabrera — to try and replicate some of their swing path.

“Hand placement, bat path, being on plane a long time,” Dickerson said. “Being super short to the ball.”

This has all allowed Dickerson to evolve in an unlikely way. He’s the rare hitter who has dramatically changed his hit tool. We don’t see that every day, but Dickerson offers evidence that perhaps it’s a skill that more hitters could change if being honest with themselves after evaluating their strengths and weaknesses. As baseball has zagged, Dickerson has zigged like no other hitter.