Platoon splits have always existed, and teams have always tried to exploit them. In the epoch of sabermetrics, though, the sport has gained a greater understanding of the mechanisms underneath splits. One of the larger things we’ve seen is that (most) all pitchers will fare better against same-handed batters. This means that a club wants its righties to face righties and its lefties to face lefties — in other words, it wants to have the platoon advantage. Some teams succeed in this quest; others fall short. As of late, the Brewers have succeeded.

In 2015, the average major-league team had the platoon advantage for 46 percent of its batters faced, per B-R. Milwaukee had the advantage 53 percent of the time, the highest rate in baseball. This continued a trend for the Brew Crew: In 2014, they also led the majors; in 2013, they ranked third; and in 2012, they ranked sixth. (Disregard the fact that they finished 22nd in 2011, as that goes against the narrative.) For some time now, Brewers pitchers have had a leg up on the competition.

Some of this stems from the nature of the pitching staff, which tends to skew right-handed. Teams without many southpaws will have the platoon advantage more often:

On the bottom left of the graph (which shows teams from 2015), we see the Chris Sale/Jose Quintana/Carlos Rodon-led Chicago White Sox, who ran out a righty for only 41.9 percent of opposing plate appearances. Since most batters are righties, this meant they largely lose out on the platoon advantage. By contrast, batters faced a right-handed Milwaukee pitcher 91.0 percent of the time, the third-highest rate in baseball. Having more righties on your staff means you’ll perform better against righty-heavy squads — which is to say most of them — and means you’ll have the platoon advantage pretty frequently.

But the lack of lefties on the Brewers doesn’t account for everything. The team’s righties also tend to face right-handed adversaries. Last season, the average right-handed pitcher on the Brewers saw a same-handed batter 54.2 percent of the time. That’s notably higher than the MLB average of 52.6 percent. And it wasn’t just one pitcher, either — several of the big names got in on the action:

Nelson and Fiers each beat the average by a significant margin, while Garza, Lohse, and Jungmann hung right around it. Only Peralta had to deal with a lot of lefties, and even then he wasn’t in too bad of a situation. They also received some success from their notable southpaws in this area — Will Smith pitched to 43.9 percent lefties and Neal Cotts did so 40.5 percent of the time, compared to a major-league average of 29.8 percent for left-handed pitchers. In the end, it’s not surprising that Milwaukee had the platoon advantage so often.

Why do these pitchers get to take on (relatively) easy competition? For most of them, it’s because they’ve played pretty indiscriminately to this point. Only Nelson and Peralta have significant platoon splits. Garza and Fiers have no career platoon splits; for the most part, neither does Jungmann, although his is an odd case. While Lohse has something of a weakness against lefties (.283 multi-year TAv, compared to .263 for righties), it’s not too significant. In 2015, the team’s pitching sucked — but it sucked evenly, against righties and lefties. Teams haven’t had an incentive to stack their lineups with opposite-handed hitters, so they haven’t.

So can the Brewers keep this up? I certainly don’t see why they wouldn’t. According to PECOTA, right-handed pitchers will consume 87.8 percent of their 2016 innings, which would again rank among the major-league leaders. And while they won’t have Fiers around anymore, Chase Anderson (career righty rate of 54.2 percent) should fill in for him nicely. With all of the younger arms throwing from the right — only Sean Nolin comes to mind as a developing lefty — this team should continue to rely on right-handers, and take the platoon advantage, for 2016 and beyond.

On Monday, the Brewers will kick off the season against the Giants. Wily Peralta will take the mound versus Madison Bumgarner, and we’ll focus more on home runs and strikeouts than on silly peripheral statistics. Still, things such as the platoon advantage matter — the little upgrades can separate the bad teams from the good, and the good from the great. Although the 2016 Brewers will most likely fall into the former group, they should sustain their excellence in this esoteric regard.

Had I taken the time to examine his splits, I would have seen an area where he certainly did improve: against right-handed hitters. During Anderson’s rookie year, lefties notched a .254 TAv when facing him, but righties crushed a .289 TAv off him. As a sophomore, he continued to hold left-handers down, to the tune of a .261 TAv, while he lowered his right-handed TAv against to .267. That massive 22-point jump ensured Anderson would keep his spot in the rotation, whereas before a trip to the bullpen might have awaited him.

Anderson didn’t beat righties by blowing them away — his strikeout rate against them dropped from 24.6 to 15.5 percent. At the same time, though, he cut his walk rate from 6.7 to 4.4 percent and reduced the quality of contact off him. His BABIP and home-run rate versus same-handed hitters fell from .374 and 3.4 percent, respectively, to .297 and 3.2 percent. In other words, his evolution against right-handers epitomized his evolution overall.

In terms of pitch background changes, there are a few. First and foremost, Anderson moved his location:

The 2014 version of Anderson threw 71.5 percent of his pitches in the lower three-fifths of the zone; the 2015 version took that up a notch, to 80.0 percent. That helped him increase his ground-ball rate against righties from 41.0 percent to 46.7 percent, which would account for the decline in home runs and BABIP.

Anderson didn’t stop there, though. He also altered his pitch usage when facing right-handed hitters:

Essentially, Anderson switched his curveball and changeup. He decreased the former by ten percentage points (from 24.7 to 14.2 percent) and increased the latter by eight (from 12.8 to 20.9 percent). The changeup has always stood out for Anderson — per FanGraphs, it’s been worth 14.8 runs over the past two seasons, putting him just outside the top ten — so that change seems advantageous. The higher strike rate that the changeup brought helped Anderson when it came to free passes, which negated the absence of strikeouts.

Can Anderson continue to retire righties with this recipe? Changeups can have a reverse platoon split, and if he keeps relying on his cambio versus right-handers, he might run into trouble. With that said, the overall quality of the pitch, combined with the strength of his sinker (which tends to fare better against same-handed hitters) should compensate for that. Plus, he does have the location change, which should allow him to maintain the soft contact and keep him, at the very least, competent.

Anderson will get a run through the rotation in 2016, and we’ll get a more definite answer regarding the 2014/15 question. Before then, we can somewhat conclusively say that he’s gotten better against righties. Whereas the role of a LOOGY once awaited him, he now has the potential to stick as a starter, as he’s finally figured out how to eliminate same-handed foes.

…plus this diving slider…

…equals, in theory, a dominant pitcher.

As we all know, however, Peralta hasn’t fulfilled expectations. His career ERA- of 103 and DRA- of 110, fitting for a back-end starter, just don’t seem appropriate for someone with this, well, stuff. That arsenal may begin to wane soon (if it hasn’t already), so at age 26, he needs to solve what ails him as fast as he can.

I’ve discussed previously how Peralta hasn’t had much movement on his pitches, which has held him back tremendously. Another, possibly more significant factor has been the presence of a platoon split. Peralta has always floundered when facing left-handed batters — they’ve clobbered a .351 career wOBA against him. He’s limited right-handed batters to a .303 wOBA, but those southpaw struggles have blocked him from taking the next step.

This is where the slider comes in. We know that this offering generally carries a platoon split: Max Marchi estimated that most sliders will perform about a half-run worse (per 100 pitches) versus opposite-handed hitters than versus same-handed hitters. This applies to Peralta, whose slider has killed righties while struggling comparatively against lefties:

*This uses the general wOBA formula, meaning the result may differ from his actual wOBA by a point or two.

Peralta hasn’t altered his slider usage by the batter handedness, though — he’s thrown it 27.3 percent of the time to righties and 28.3 percent of the time to lefties. In fact, when he’s notched two strikes on a southpaw, he’s actually relied on it more often (44.0 percent) than in the same situation against their counterparts (38.0 percent). Why would Peralta make this his out-pitch when it hasn’t fooled lefties that well?

In this regard, the slider has still fared much better than his other offerings. Peralta’s four-seam fastball, sinker, and changeup have respective lefty wOBAs of .385, .379, and .364. This incompetence has forced him to lean on the slider as the lesser evil. Changeups typically subdue opposite-handed hitters, so if Peralta can improve his changeup — as he vowed to do last spring — to a usable level, it could replace his slider as the lefty killer he needs.

Until then, Peralta must stick with the slider, which we’ll now return to. Beyond its implementation, the slider also has some bizarre splits. In terms of strikes, called strikes, and swinging strikes, it’s demonstrated a difference in the opposite direction that we’d predict:

Left-handers have taken the slider for more strikes and have missed it more often, all without sacrificing any looks. How have they demolished it while posting these numbers?

The slider epitomizes the contradictions of Peralta’s platoon split overall. For his career, he’s struck out and walked about the same amount of lefties and righties. The disparity stems from balls in play:

Likewise, the slider has seen spikes in its ISO (from .039 to .166) and BABIP (from .250 to .325;) versus lefties. This seems to stem from its location, which Peralta hasn’t successfully shifted by batter handedness:

Peralta has kept the slider low against everyone — 71.4 percent of his righty sliders and 71.9 percent of his lefty sliders have gone to the bottom two-fifths of the zone. Since he’s accumulated the most whiffs and swings there, this has helped him to rack up the strikeouts and avoid the walks. But he’s also placed it inside more often against opposite-handed opponents (33.8 percent in the inner two-fifths) than against same-handed ones (8.2 percent). This has allowed the former to pull those pitches with gusto, making harder contact and thus posting higher BABIPs and ISOs.

To some extent, this seems like an antithetical mix, one that will likely disappear away in the future. Surely southpaws can’t continue to miss so many sliders and batter them when they don’t. And certainly, platoon splits require significant regression when looking to the future. With that said, the overall trends here may not change. Peralta’s slider, like many of its species, darts down and away to righties and down and in to lefties. The common vertical location gives them some shared characteristics, while the horizontal differences establish its platoon split — just as they do for many slider-heavy pitchers.

As a whole, the good outweighs the bad for Peralta’s slider. That stuff has created a healthy amount of whiffs and a good deal of grounders, leading to an overall wOBA of .238 off it. Worth 9.1 runs according to FanGraphs, it’s served him better than any other pitch in his repertoire. Still, it hasn’t performed at the level that it should have — just like Peralta himself. Only by mastering this pitch can he take down lefties and become the top-notch pitcher that he should be.

Presumably, those same fans would like Jungmann to keep this up. While they certainly appreciated everything he did for the club this season, it ultimately didn’t count for anything — whereas in 2016 and the years that will follow it, Milwaukee might actually need a hurler to lead its rotation. Will Jungmann repeat his 2015 campaign, or will he regress to the mediocrity that most scouts foresaw from him as a farmhand? The answer to that may hinge upon his ability to pitch indiscriminately, which is where our fascinating tale begins.

As my boss J.P. Breen noted earlier this year, Jungmann had a reverse platoon split in the minors:

Strangely, despite throwing with his right hand, Jungmann continually found more success against left-handed batters. And even more strangely, he did the exact opposite upon arriving at the show:

In 2015, the average right-handed pitcher tallied a .701 OPS against righties (which Jungmann beat by four percent) and a .747 OPS against lefties (which he beat by two percent). In other words, Jungmann had no platoon split in his major-league debut. So which version is the real one?

Let’s first examine Jungmann’s minor-league splits by batter handedness, which have an unusual breakdown:

He struck out more right-handed batters, walked fewer, and allowed hits on balls in play at the same clip as he did to left-handed batters. The only real difference came in terms of power (and hit-by-pitches, which I’ll discuss next week). As a major leaguer, Jungmann saw three of those trends remain steady, while one went crazy:

The K, BB, and ISO disparities didn’t shift, but the BABIP commonality evaporated. Jungmann simultaneously cut down on hits versus righties and gave up far more versus lefties. This combination granted him the power to retire everyone who batted against him, which played a large role in his splendid season.

On a pitch-by-pitch basis, we can spot a clear outlier. Jungmann’s sinker, curveball, and changeup — i.e., his three secondary offerings — each posted a marginally higher BABIP when thrown to righties. The gap came from his primary pitch: Jungmann’s four-seam fastball went for a hit 25.0 percent of the time a right-handed batter put it in play and 37.7 percent of the time a left-handed batter did so. The heater, which comprised 55.3 percent of his pitches this year (about the same for everyone), made all the difference.

Based on his heatmap, Jungmann didn’t seem to make any massive changes in four-seam location based on the handedness of the batter:

Against all opponents, Jungmann threw his fastball mostly toward the middle-ish of the plate, occasionally going to the upper left and the lower right. Given this, we might conclude that the dropoff in BABIP was just a fluke.

Here’s the thing, though: Those pitches looked different to different batters. According to the theory of effective velocity, pitches up and in appear faster, while pitches down and away appear slower. Since greater velocity obviously works in the pitcher’s favor, this means it behooves him to (within reason) target the former area. When Jungmann threw his four-seamer to a same-handed batter, it would tail up toward them, where they wouldn’t be able to make good contact. The lefties got pitches to the same height, but outside more, where they could handle it better.

Think of it this way. Jungmann located his secondary pitches thusly based on handedness:

Here, we see a clear shift to a down-and-away approach for everyone (which may reflect team policy). And, as mentioned above, these offerings didn’t differ in BABIP here either. Because Jungmann threw his four-seam fastball in a more even manner, he put up a sizable BABIP difference, one that played an integral role in eliminating his platoon split.

We can’t really know how this differs from what Jungmann did in the minors, since comprehensive PITCHf/x data for his time there doesn’t exist. Further, BABIP — as you know by now — can fluctuate a lot without reflecting a true change in skill. We should therefore expect the left-right ball-in-play gap Jungmann displayed this year to regress somewhat going forward, which means his reverse platoon split may return.

With that said, the fact that his underlying process supports this means the 2015 results could stick around. And, for what it’s worth, his batted-ball profile backs up the split — righties had a 25.3 percent hard-hit rate and a 23.0 percent soft-hit rate off him, compared to a respective 29.7 and 15.8 percent for lefties. Overall, it certainly seems that Jungmann can sustain this, pairing solid strikeout and walk marks against right-handed batters with a low BABIP.

In all likelihood, the phenom that was early-2015 Taylor Jungmann will never resurface. He still has mediocre command and poor mechanics to boot. That doesn’t mean that Jungmann can’t continue to prosper at the major-league level, or that he’ll stop giving the Milwaukee faithful a reason to cheer.