If you haven't had a chance to check it out, one of the new Statcast tools over at Baseball Savant is fun to play with: the swing/take tool. It's a visualization method, unveiled in September, that allows for the charting of how the aggression (or lack thereof) by a hitter in various parts of the strike zone affected his expected run value at the plate.

In essence, we can, to some degree, assess how a player's unbridled aggression (think Eddie Rosario) or patience (how about someone like Luis Arraez?) affects the run values of their seasons.

The tool divides the strike zone into four areas: the heart of the plate, the "shadow" region encompassing the edges of the zone, the "chase" region where pitchers are trying to draw swings on clear balls and the "waste" region where batters really shouldn't be swinging.

Simply put, the outcome of every pitch can be assigned some positive or negative value for the hitting team. Grounding out with the bases empty will obviously result in negative value, while taking a ball to go from a 2-0 count to a 3-0 count will result in a positive value. A home run would result in a (larger) positive value. Greater detail from sabermetrician Tom Tango can be found in a post here.

In the visualization, every pitch to each batter during the season was classified into one of the four zones, divided into swings and takes and assigned values to determine how advantageous his takes and swings were in each zone.

Why does this matter? Because the Twins have an interesting outlier and several trends from certain players that have been reported on that can be examined more easily using this tool. Let's take a Minnesota-centric look.

The outlier: Eddie Rosario

So, first, the pressing question from Twins fans whenever the idea of "aggression" comes up: is Rosario's pronounced aggression at the plate closer to a net positive or negative? Both anecdotally and statistically, Rosario is known to have very loose restraint at the plate, but he also often does damage to pitches well out of the zone.

That's what manager Rocco Baldelli said all season: Rosario may swing out of the strike zone, but the concept of tuning his eye or aggression to a more "traditional" strike zone might take away from his uncommon ability to actually produce runs on pitches outside the zone.

Looking at his chart, Rosario's aggression is clear in the bars second from right -- his swing rates in the "heart" and "shadow" areas are well above the MLB average, while he actually swings nearly twice as often on pitches in the "chase" and "waste" areas. And in fact, the negative value of his swings in the "shadow" and "chase" areas -- a combined minus-19 runs -- more than negates the damage that he actually does on hittable pitches in the heart of the plate, which were worth plus-10 runs to his season.

This chart obviously isn't a tell-all, especially stripped of context, but it does look to suggest that while Rosario befuddles pitchers by occasionally hitting a pitch two feet inside out of the park, his ball-in-play contributions on said pitches are, in aggregate, a negative. It's still an improvement from his 2018 chart, though, which shows that he has gotten much better at doing damage to hittable pitches in the zone.

The improvement: Max Kepler

Speaking of doing damage to hittable pitches, let's move over to Kepler, for whom it has anecdotally been said -- backed up by some stats -- that much of his breakout in 2019 came from an increased selectivity at the plate, and that he had gotten better at laying off bad pitches and swinging hard at hittable pitches. And that's exactly what his chart shows.

Kepler is shown to display MLB-average aggression in the "shadow," "chase" and "waste" areas of the plate, but he well exceeds the MLB average in swinging at pitches in the heart of the zone, where his swings were worth plus-14 runs. Noting also the plus-27 runs he gains from taking pitches in the "chase" zone and the plus-12 take contribution from the "waste" zone, it certainly looks as though Kepler's discipline yields strong results.

Like Rosario, this shows a marked difference from '18, when Kepler was actually less aggressive -- and effective -- than average on pitches in the heart of the zone and was thus worth negative run values on both his swings and takes in that hittable area. In both years, though, his inability to derive positive outcomes on his swings in the "shadow" area at the edges of the strike zone are a noted area for improvement.

The value of power: Luis Arraez and Mitch Garver

And finally, let's wander all the way over to the area populated by the most selective Twins, where Arraez and Garver reside. It's clear from looking at their charts that both Arraez and Garver derive plenty of positive value from their selectivity on bad pitches, and both of their swing-take rates are relatively similar.

As you can see, though, while their respective "take" values are fairly similar across all zones because of that, Garver vastly exceeds Arraez in overall run value because of the marked difference between the two in "swing" runs in the heart of the zone. Garver, who slugged .630 last season with 31 homers, is worth plus-21 swing runs in that hittable area, while Arraez was only worth plus-1 after slugging .439 with four homers.

It's also worth noting that Arraez is much closer to neutral than other examples we've seen in this article on his swing values at pitches outside the zone, as his swings on pitches in the "shadow," "chase" and "waste" areas only combine for minus-5 runs of negative value. That's a testament to his ability to not only put bat to ball, but also net positive outcomes on many of those offerings. But as this example shows, discipline alone isn't everything -- it also matters quite a bit what a hitter can do with the pitches he swings at.