What happens when an extra-base-hits machine taps into even more power? Nick Castellanos might have an answer for you.

The Reds' right fielder has emerged as one of the Majors’ elite sluggers through the quarter-mark of the season. Castellanos homered for the seventh time in Friday’s win over the Brewers, which at the time tied him for the MLB lead.

Though this may seem like a breakout, Castellanos has actually been trending up for the past calendar year, when he was dealt ahead of the 2019 Trade Deadline from the Tigers to the Cubs. In 51 games in Chicago, he homered 16 times in 51 games while becoming just the 10th player in history to rack up 58 doubles in a season and the first right-handed hitter to do so since 1936.

With a career .802 OPS and a 114 OPS+, Castellanos has always been an above-average hitter. But what he’s doing in 2020 is in MVP territory, which Castellanos -- who has never been an All-Star -- has never reached. It's safe to say, the early returns of the four-year, $64 million deal he signed on Jan. 27 make him the most impactful free-agent acquisition in the young season.

Of course, this is a sample size of just 16 games. But in this shortened season, Cincinnati is already beyond the one-quarter mark, and Castellanos is the National League’s hottest hitter not named Fernando Tatis Jr.

Here is a breakdown of his breakout:

He’s raking with the best of them

Glance at the Statcast leaderboards, and Castellanos’ name is at or near the top of just about every major category for contact. None is more revealing -- or important -- than the rate at which he’s barreling the ball.

Barrels are a Statcast designation for the very best hits that give tangible support to what the eye test has shown for years. They put formulaic backing to a hitter’s contact based on a combination of exit velocity and launch angle. Barrels turn into an extra-base hit half the time, and most homers are barrels.

Most barrels since the 2019 Trade Deadline

1. Jorge Soler: 38

2) Nick Castellanos: 36
3) Eloy Jiménez: 34
4) Miguel Sanó: 32
5) Aaron Judge: 29

This year, Castellanos has ripped a barrel in 15.2% of his plate appearances, which trails only Mitch Moreland, Corey Seager (who has also been off to a scorching hot start) and Tyler O'Neill, and it's well above Castellanos’ previous career high of 9.8% in 2016.

Castellanos’ barrel per PA rate / MLB rank among qualifiers
2015: 5.2% (74th of 250)
2016: 9.8% (6th of 241)
2017: 7.7% (23rd of 256)
2018: 7.9% (42nd of 250)
2019: 7.8% (61st of 250)
2020: 15.2% (4th of 261)

As such, it should come as no surprise that Castellanos’ exit velocity readings are way up this year too, to 91.1 mph, up from his career average of 89.1 mph since the start of 2015, when Statacst came online. More telling, Castellanos is reaching into elite exit-velocity territory more often, passing the 95 mph hard-hit threshold on 51.2% of the balls he’s putting in play -- up from his career average of 39.8% before ’20. He’s hit .536 and slugged 1.142 on those batted balls.

These are elite results, and he's accomplishing them at a higher rate. That's what you want.

So, what adjustment did he make?

Castellanos is still striking out at around his career rate, 26.2% this season, and he still succumbs to low-and-away balls. But two things stand out: 1) He’s better at exploiting pitches in the zone, and 2) doing so with better swings.

Castellanos has raised his overall launch angle from 14 to 22.1 degrees, going from an average in the fringe line-drive range to one in the sweet spot area. (For context, Mike Trout averaged a 22.2-degree launch angle in 2019).

It’s worth noting that this average launch angle includes all batted balls, including poorly struck outs. But let’s zero back in on the strike zone again -- Castellanos has created more lift there, which, coupled with enhanced exit velocity, will lead to balls getting in the air higher and traveling further.

Is this sustainable?

Believe it or not, Castellanos is underperforming. … Wait, what?

Thanks to Statcast’s wide-ranging expected metrics, which uses data of similar batted balls, we can see how hitters should fare compared to their actual numbers. Such figures have illuminated the fact that that some slumping hitters might be victims of poor luck -- such as Matt Carpenter before he thrust himself into the MVP conversation in 2018, and Kris Bryant when he kept crushing 105-mph outs at the start of '19, among many others.

It’s not all that often that a player hitting at a superstar level underperforms his expected numbers. But Castellanos is in that camp in 2020. In fact, this is a career trend.

Castellanos' actual vs. expected numbers, 2020
BA: .293 | .333
SLG: .724 | .750*
wOBA: .443 | .473*
*Top 1% of MLB

Now, we’re not going to say that his actual numbers are going to skyrocket into a stratosphere of hitting like Ted Williams and slugging like Barry Bonds. But expected metrics lend credence to this trend not just being a fluke. And given that Castellanos plays home games at hitter-friendly Great American Ballpark -- which MLB.com’s Mike Petriello highlighted would be a big boon to Castellanos after he signed -- there’s a good chance Castellanos might have found a hitter’s haven.

He also might have found leverage for this offseason, as Castellanos’ deal has an opt out after this season and 2021. The pandemic has presented plenty of financial uncertainty for all clubs, but hitting sells, and Castellanos might be positioning himself nicely for not only a career year, but also a possible selling point -- to the Reds and the rest of the league.