A Tale of Two Halves for Trevor Bauer

Attitudes towards athletes are commonly molded by preconceived notions and subjective feelings about the way they carry themselves, their belief systems, and – most importantly – production. This rings true with Trevor Bauer. His confident, borderline arrogant, quips to reporters following rough performances rub some folks the wrong way. His passionate, borderline emotional, demeanor on the mound creates narratives about his maturity. Add a careless injury while working on a drone followed by the divisive political commentary in which he took the liberty of speaking for his teammates and you have a polarizing figure.

These parts of Trevor Bauer create a persona that is detestable for certain groups of fans but cannot be overlooked. They are what make him successful. His passion, confidence, intelligence, quirkiness, and conviction combine to form a pitcher that is dedicated to both the mental and physical aspects of his craft. These traits make him tick.

And tick, he does. Since the beginning of 2016, he has been a borderline Top 10 pitcher in the American league. His 5.2 fWAR over that time period is No. 13 in the AL, but he also has significantly fewer innings pitched than several names directly ahead of him. That fWAR mark is not wholly indicative of results but is more focused on his ability to corral the inputs that a pitcher controls and translate them into value.

The first half of Trevor Bauer’s 2017 was the perfect example of saber-inclined schools of thought versus old school methodology. His ERA skyrocketed to 5.24 by the break, leaving saber skeptics questioning his ability to pitch at the big league level. The peripherals showed promise, however. That 5.24 ERA was bolstered by stranding only 67.9 percent of runners and 17.1% of the fly balls allowed resulting in home runs. League average in these categories resides 72.7% and 13.8%, respectively.

Bauer was disastrously unlucky throughout the first half of this season. LOB% and HR/FB% rely little on pitcher inputs. Deviations from the mean in these categories are just variance in most cases and regression towards the mean can be expected.

Regression towards the mean has occurred since the All-Star break. His result-based numbers have bounced back in a big way, evidenced by his 3.28 ERA in that time frame.

One would think that something has drastically changed, but it has not. Bauer’s strikeout and walk numbers across those splits are nearly identical. The old school thinking crowd might then point to batting average, but Bauer has actually allowed more of his batted balls to go for hits in the second half of the season. He is still the same pitcher, but the percentage of hard contact allowed has decreased by nearly 20%.

The curious aspect of that decrease in hard contact allowed is that it runs opposite a BABIP spike from 0.336 in the first half to 0.371 in the second half, which has resulted in a jump of his batting average allowed. Hard contact allowed and ERA are down significantly, while batting average is up. This might be a riddle for the anti-saber crowd, but it’s really much simpler.

Variance. It is seemingly universally applicable in the world of statistical analysis. Throughout the second half of 2017, Bauer has stranded 85.8% (!) of runners. Sequencing luck is prevalent, but that does not mean we should expect him to revert back to first half form.

Bauer’s expected weighted on base average (xwOBA) is down in the second half. The first half of 2017 xwOBA of 0.336 left something to be desired. The decrease in hard contact allowed in the second half has resulted in an xwOBA of 0.304. Despite managing contact better, he has actually allowed a higher actual wOBA in the second half. If Bauer can continue to manage contact, better luck on balls in play should cancel out any left on base percentage regression.

Another year of identifiable improvement for Trevor Bauer, and a statement that he is belongs in the conversation among the American League’s best. This offseason it will be time for Mike Chernoff and Chris Antonetti to break out the Dolans checkbooks and ink another pre-arbitration player to another team-friendly deal.