You probably didn’t pay much attention or even notice when the New York Yankees acquired twenty-eight year old outfielder Mike Tauchman from the Colorado Rockies in exchange for pitching prospect Phillip Diehl towards the end of spring training on March 23rd. Who could blame you? Tauchman’s major league resumé to that point was ugly: a .153/.265/.203 slash line in 69 plate appearances over 52 games for the Rockies.

From 2013 to 2016 in the Rockies farm system, Tauchman hadn’t shown much in his age 22 to age 25 seasons. He displayed a decent hit tool but didn’t flash much power, combining for only eight home runs across four minor league seasons. If Tauchman wanted to crack Colorado’s major league roster, he needed to make a change.

Prior to the 2017 season, as reported by the New York Times’ James Wagner, Tauchman worked with Justin Stone, a hitting instructor at Chicago-based Elite Baseball Training. With three-dimensional sensors and plates that measure force, Stone, who was hired as a hitting consultant by the Chicago Cubs in 2018, used biomechanics to help Tauchman improve his swing. Stone and Tauchman found that the former Rockie was transferring energy inefficiently from his lower half to his upper half. In scientific terms, Tauchman’s kinetic chain, or the sequence of movements that make up his swing, was off. With Stone’s help, Tauchman learned to use his lower half better when starting his swing, enhancing the transfer of energy up the kinetic chain.

The results were undeniable. Still in AAA, Tauchman improved his wOBA from .322 in 2016 to .399 in 2017 and .420 in 2018. His 139 wRC+ was good for the eight-best mark in AAA in 2017. In 2018, his 153 wRC+ was fourth-best, just behind fellow 2019 breakouts Daniel Vogelbach and J.D. Davis as well as Astros top prospect Kyle Tucker. Tauchman’s power had definitely increased: he tripled his career home run mark with sixteen homers in 2017 and swatted another twenty in 2018. The Yankees front office took notice and was intrigued enough by Tauchman’s minor league success to add him as a depth piece just before the 2019 season.

Tauchman’s rise has continued in 2019. In 71 games, he’s posted a .381 wOBA and 138 wRC+. That wRC+ ranks Tauchman twenty-ninth among 309 players with 200 or more plate appearances in 2019, just ahead of Josh Bell, Jose Altuve, and Anthony Rizzo. Tauchman’s done more than just impress with the bat in 2019. According to FanGraphs, he’s created 1.4 runs on the basepaths this season.

Tauchman has also shined with the glove in 2019. He’s played 559.2 innings in the outfield for the Yanks: 363 in left, 74.2 in center, and 122 in right. Tauchman has been above average defensively in all three spots and amassed a stellar fourteen defensive runs saved, which ranks him sixth among all outfielders with at least 500 innings played. To give you a sense of how good Tauchman has been defensively, he’s just two defensive runs saved behind the Tampa Bay Rays’ Kevin Kiermaier in almost three hundred less innings played.

Statcast numbers available at Baseball Savant agree that Tauchman has been outstanding in the field this season. Tauchman ranks tenth among ninety-five qualified outfielders with seven outs above average this season. Using the exit velocity and launch angle of the batted balls hit in Tauchman’s direction in 2019, Statcast calculates that 85% of those batted balls should have been converted into outs. Tauchman has caught 91% of those balls, good for the second-best catch percentage added in the league at 6% behind only Kiermaier’s 7%. Statcast’s Outfielder Jump metrics also rank Tauchman above average at twenty-seventh among the 105 qualifying outfielders.

Tauchman’s all-around game has contributed 3.4 bWAR in just 71 games played for the Bombers in 2019. However, there are some warning signs that his offensive breakout might not be sustainable. First, there’s a discrepancy between Tauchman’s .381 wOBA and his expected wOBA as calculated by Statcast based on the exit velocity and launch angle of his batted balls. His xwOBA is a mere .324, suggesting that luck has played a large part in Tauchman’s offensive success. Additionally, his .353 BABIP is fifty-four points above the league average .299 BABIP. With a pedestrian average exit velocity of 88.8 miles per hour, it’s likely that Tauchman will see his BABIP decrease and his offensive numbers regress somewhat. That said, according to Baseball Savant, Tauchman owns a 38.4% sweet spot percentage in 2019, which ranks him seventy-first of 436 qualifying hitters. Sweet spot percentage tallies the percentage of balls a batter hits in the ideal launch angle range between eight and thirty-two degrees. Since 2015, batted balls in the sweet spot have led to an average BABIP of .514 and average wOBA of .707.

There’s more to combat the assertion that Tauchman’s offensive breakout is just a mirage. Tauchman’s season has truly been a tale of two halves. The table below helps tell the story.

Tauchman’s actual wOBA is still outstripping his xwOBA by quite a bit over the last month, but his .369 xwOBA is nothing to sneeze at: it’s good for fifty-seventh among the 344 hitters with at least fifty plate appearances from July 11th through August 17th. The increase in his launch angle shows that he’s lifting the ball a lot more and that’s borne out in his batted ball profile as well.

Tauchman’s ground ball rate has dropped dramatically in the second half, and his fly ball rate has increased by a significant amount. His 31.0% line drive rate is almost certainly unsustainable (Whit Merrifield of the Kansas City Royals currently leads the league at 29.7%) and has likely driven much of Tauchman’s success, but given the sweet spot percentage mentioned above, he may be predisposed to hit line drives more frequently than the typical hitter. As expected given his line drive rate in the second half, Tauchman has been hitting the ball harder more often.

A more refined pitch selection appears to be what’s led to Tauchman’s offensive breakout over the last month.

Tauchman had already displayed excellent plate discipline in the first half with a chase rate that ranked forty-second among 437 hitters with at least fifty plate appearances. He’s improved upon that skill in the second half, as he’s swinging less overall, chasing less frequently, and swinging less often in the strike zone. His second half swing rate ranks thirty-third lowest among 345 hitters with at least fifty plate appearances, and his chase rate ranks twentieth among the same group. His even more patient approach after the All-Star break has led to more contact: he’s increased his contact rate by almost 6% and decreased his swinging strike rate by 3.2%. Below are his overall swing percentage heat maps from the first and second halves of the season.

Tauchman has really concentrated his swings in the middle of the zone, especially the inner-middle part of the plate, swinging most often in the upper-middle part of the zone. He’s also laying off pitches low and away and above the zone a lot more frequently. Swinging at pitches higher in the strike zone and staying off that low and away pitch probably has a lot to do with the reduction in his ground ball rate. You can see the same trend against four-seam fastballs, which Tauchman is seeing 42.1% of the time in 2019.

It’s most likely that Tauchman won’t be able to sustain all of his offensive breakout over the last month. Maintaining a near .400 BABIP is unheard of and Statcast shows that Tauchman has definitely been the beneficiary of some good luck. Even when regression comes for Tauchman, however, there appears to be enough to believe that he’ll retain some of that breakout. He has shown elite plate discipline and an above-average ability to put the bat on the ball. Those attributes will serve any hitter well. If he’s able to keep enough of his batted balls in the air, given his above-average base running and excellent defense, Tauchman has shown the tools to continue to be an above-average regular moving forward.

Towards the end of writing this, Trevor Bauer was traded in a three-team deal from the Cleveland Indians to the Cincinnati Reds. The Reds sent highly-touted outfield prospect Taylor Trammell to the San Diego Padres and outfielder Yasiel Puig and minor league pitcher Scott Moss to the Indians. The Padres sent outfielder Franmil Reyes and 3B/2B/OF Victor Nova to Cleveland. On the off-chance the Reds flip Bauer before 4 p.m. today (or even if they don’t), there’s some interesting stuff here about Bauer.

In 2018, Trevor Bauer had finally put it all together. The number three overall pick in the 2011 amateur draft was on his way to a potential American League Cy Young Award before being struck by a José Abreu line drive in August of last season. The resulting stress fracture in his fibula sidelined Bauer from August 11th to September 21st and limited him to 175.1 innings in 2018. Despite the lighter workload, Bauer finished sixth in the AL Cy Young voting with a 2.21 ERA, 2.44 FIP, 56 DRA-, and 221 strikeouts.

Bauer seemed poised to make another run at the AL Cy Young in 2019, but the controversial right-hander has taken a step back in his age twenty-eight season. In 156.2 innings pitched, he’s worked to a 3.79 ERA, 4.17 FIP, and 98 DRA- in 2019. That decline is also reflected in his peripheral statistics.

Bauer is missing less bats, getting hitters to chase less often, walking more batters, and giving up harder contact. Stuff doesn’t appear to be an issue for Bauer this season. His average fastball velocity has actually increased slightly in 2019, and the well-above average movement on his pitches has, for the most part, improved or remained steady, with the exception of his slider and changeup. While Bauer’s slider movement has decreased slightly compared to average, its horizontal break still ranks 28th of 270 sliders thrown at least 100 times in 2019, so it doesn’t seem to be a real cause for concern. The table below shows how much more or less movement each of Bauer’s pitches get compared to the average MLB pitch thrown at similar velocities.

One note on Bauer’s cutter: he uses the pitch differently than a lot of pitchers, and “cutter” may not actually be the best name for it. Bauer wants his cutter to have less horizontal movement and more drop than his slider, giving hitters one more thing to worry about in his arsenal when they think they’ve detected one of his other offerings (or vice versa). Here’s an example of the intended effect in tandem with Bauer’s slider (GIF from Pitching Ninja).

That quick aside aside, command looks like the thing that’s been ailing Bauer in 2019. As noted above, he’s walking more batters in 2019. Additionally, his zone rate (rate of pitches thrown in the strike zone) has decreased from 42.0% in 2018 to 40.4%. What’s more, he’s working behind batters much more often. His first-strike rate (the rate at which a pitcher goes 0-1 on a batter as opposed to 1-0) has shrunk from 63.7% in 2018 to 58.9% in 2019. Below is a graph showing how frequently Bauer has found himself in each pitch count in 2019 compared to 2018.

In addition to the above numbers, per Baseball Savant, 2019 Bauer has been behind in the count 27.37% of the time, even in the count 44.25% of the time, and ahead in the count 28.38% of the time. In 2018, those numbers were 25.13%, 44.13%, and 30.74%. As you might imagine, being behind in the count is bad for pitchers. According to Baseball Savant, since 2015, all batters have hit for a .424 wOBA when ahead in the count, .305 when even, and .223 when behind. Essentially, when hitters are ahead in the count, they hit like 2019 Anthony Rendon; when they’re behind in the count, they hit like 2019 Juan Lagares. Bauer’s lack of command is giving hitters a head start in 2019.

The table above from Brooks Baseball shows Bauer’s pitch usage in 2019. You can see that, down in the count, Bauer tends to go to the four-seam fastball, particularly against lefties.

Left-handed batters have teed off on Bauer in 2019: he’s allowed a 5.29 FIP and a .340 wOBA against while surrendering 15 of his 22 home runs allowed to lefties. Bauer has had trouble putting lefties away as well, striking out only 24.6% of left-handed batters. That pales in comparison to Bauer’s numbers against righties in 2019: a 3.13 FIP, 30.6% strikeout rate, and .275 wOBA allowed. In contrast to 2019, in 2018, Bauer stifled lefties to the tune of a 2.65 FIP, .256 wOBA against, and 29.5% strikeout rate.

Above is a heatmap of Bauer’s four-seam fastball locations to lefties in 2018. He successfully located the ball up in the zone where a “rising” fastball is likely to get more swings and misses and pop-ups. The Indians’ starter has struggled to match that location against lefties in 2019.

Instead of middle-up, Bauer’s four-seam fastball has been more middle-middle in 2019. Lefties have taken advantage, putting up a .440 wOBA against Bauer’s four-seamer (compared to a .308 wOBA in 2018). Eight of Bauer’s fifteen homers allowed to lefties have come against the four-seam fastball. With Bauer behind in the count, lefties have been able to hunt fastballs, and Bauer’s been serving them up.

Looking back at the pitch usage table, Bauer throws the changeup 18% of the time against lefties. It’s an important part of his arsenal against them. Unfortunately for Bauer, that pitch hasn’t been nearly as effective as it was in 2018.

Below are 2018 and 2019 heatmaps of Bauer’s changeup locations against lefties with different locations split into various zones.

Bauer definitely grooved a few more changeups to lefties in 2018 than he has so far in 2019, but he also did a better job of throwing the change on the outer part of the plate, where it might get more swings and misses and induce weaker contact on the ground. Bauer has done a good job of of keeping the changeup down in 2019, but he’s had trouble keeping it away from the middle of the plate. It’s a small sample, but the fifteen changeups pulled by lefties against Bauer in 2019 have led to a .399 xwOBA and .499 wOBA; the twenty-two lefty-pulled changeups in 2018 led to a .223 xwOBA and .248 wOBA. In addition to hitting the ball with more authority due to the more central location, lefties are likely spitting on most of those lower-than-low changeups you see at the bottom of the 2019 map.

Command isn’t the only issue with Bauer’s changeup in 2019. As noted earlier, it’s also suffered from decreased movement in 2019.

Batters have swung and missed less frequently as a likely result of the dual decrease in movement. In addition to the lower whiff rate (the number of swings and misses over all swings) shown above, according to data available at FanGraphs, the swinging strike rate (the number of swings and misses over all pitches) on the changeup is down from 15.2% to 11.8%. The contact rate is up from 64.3% to 69.7%, spurred mostly by the out-of-zone contact rate, which is up 16.6% from 39.3% to 55.6%.

Bauer uses his four-seam fastball and changeup 56% of the time against lefties and 73% of the time when lefty hitters are ahead in the count. It’s not surprising that he’s found it difficult to get left-handed hitters out in 2019 given the deterioration of two of his primary weapons against lefties.

Bauer has also had command issues with his slider in 2019. He uses the slider almost exclusively against right-handed hitters, throwing it 24% of the time overall against righties. He throws the pitch 40% of the time when he’s ahead of right-handed batters and 37% of the time with two strikes against them. To put it simply, it’s his go-to pitch when trying to put away righties. In 2018, hitters could hardly touch the pitch; 2019 has seen different results.

The exit velocity and whiff rate against Bauer’s slider have actually improved, but hitters have been lifting Bauer’s slider more when they do make contact and seeing better outcomes as a result.

The heatmaps above detail Bauer’s 2018 and 2019 slider locations to righties. In 2018, Bauer was really dotting the slider low and away. In 2019, the pitch has been located higher in the zone and catching more of the middle of the plate, likely making it easier for righties to get the ball in the air. You can also see a gathering of sliders low and way outside in the 2019 map, more evidence that Bauer is having trouble controlling the pitch. That might be partly responsible for the decrease in chase rate and swinging strike rate against Bauer’s slider in 2019. The chase rate is down by 11.2% from 45.6% in 2018 to 34.4% in 2019, while the swinging strike rate has decreased from 21.1% to 17.6%. Generally, the more erratic location of Bauer’s sliders is leading to better contact and less swings and misses by right-handed batters against his most lethal offering.

Why Bauer’s command has suffered in 2019 is a difficult question to answer. The below graph from Brooks Baseball might be one clue.

The vertical release points on each of Bauer’s pitches other than the changeup have decreased uniformly from 2018 to 2019. If you know anything about Bauer, you know that he’s a pitcher who’s constantly adjusting, continuously striving to improve. Given the uniformity of the change, the decrease could easily be an adjustment Bauer decided to make in the offseason, but it could also be the result of something wrong with Bauer’s mechanics that he’s had difficulty correcting in-season. This will be something to watch as Bauer begins to work with Cincinnati pitching coach Derek Johnson, who seems to have ironed out whatever issues Sonny Gray was experiencing with the New York Yankees during his tenure in the Bronx.

Bauer’s tendency to get behind in the count and inability to consistently command his secondary offerings has allowed hitters to sit on the four-seam fastball. Hitters are swinging at the heater more often in 2019.

And, for the most part, hitters are laying off Bauer’s breaking and off-speed stuff more frequently than in 2018.

Unless Bauer can find a way to regain command, the trends outlined above will continue, and his future Cy Young hopes will remain exactly that. But, given his stuff, with the right adjustment, they’re more realistic hopes than most.

According to Pitch Info data available at FanGraphs, here’s how Bauer’s five most frequently thrown offerings ranked in terms of run value per 100 times thrown among pitchers to throw at least 120 innings in 2018: slider — 7th of 91 (2.78); four-seamer — 9th of 114 (1.19); changeup — 12th of 113 (1.93); cutter — 12th of 46 (0.64); curveball — 31st of 97 (0.52). Bauer commanded five above-average pitches (some of them elite) in 2018 and flashed Cy Young potential as a twenty-seven year old.

Another Diamondbacks first-round draft pick with an arsenal of five above-average pitches had his breakout as a twenty-seven year old with a team in the AL Central. The next season, Max Scherzer won the AL Cy Young and went on a run that has cemented him as a first-ballot Hall of Famer. Trevor Bauer won’t win a Cy Young this season, but he certainly has the knowledge, talent, and drive to put together that type of run.