Trevor Bauer and Critical Strikes

Trevor Bauer’s performance in 2016 has not jumped off the page, but after nine starts and a handful of relief appearances, he is enjoying a career best 3.69 ERA and 3.70 FIP. His strikeout rate has declined somewhat from 8.7 to 7.9 per nine innings, but his walk rate has declined more significantly from 4.0 to 3.0 per nine and is palatable for fantasy owners for the first time. If this is what Bauer is now, then he can finally be a fantasy asset, even if not quite in the form that many expected from him when he struck out more than a batter per inning in the upper levels of the Diamondbacks’ farm system.

The reason Bauer caught my eye was that while his walk rate has improved by a walk per inning this season, his first-pitch strike rate has actually declined slightly from 59.1 percent to 57.9 percent. It made me wonder whether Bauer’s improvements were somehow a mirage. After all, isn’t the first pitch critical for pitchers to get ahead in the count? A look at the leaderboard of first-pitch strike percentage certainly supports its importance. It’s full of names like Clayton Kershaw and Madison Bumgarner.

F-Strike% Leaders, 2016

Pitcher	F-Strike%
Matt Shoemaker	70.3%
John Lackey	70.2%
Kyle Hendricks	69.7%
Johnny Cueto	69.4%
Clayton Kershaw	68.9%
Colby Lewis	68.6%
Madison Bumgarner	68.2%
Steven Matz	68.0%
Zack Greinke	67.5%
Michael Pineda	66.7%

Bauer falls well short of the standard in first-pitch strike rate, but he seems to be enjoying control-related performance improvements. I saw that as a paradox, and so I decided to actually test my preconceived notion of the importance of a first-pitch strike. To do so, I calculated the average wOBA of every count by aggregating the results of plate appearances that passed through them. For example, a hit on a 2-1 count would fall into the bucket for 0-0, 1-0, 1-1, and 2-1 counts if the plate appearance followed that path. From there, I could compare the change in average wOBA from each count to the subsequent count if the pitcher threw a ball.

wOBA Penalty for a Ball

Count	Count wOBA	After a Ball	Diff
3-2	.376	.690	.314
3-1	.471	.690	.219
3-0	.542	.690	.148
2-0	.422	.542	.120
2-1	.354	.471	.117
2-2	.269	.376	.107
1-0	.355	.422	.067
1-1	.298	.354	.056
1-2	.223	.269	.046
0-0	.314	.355	.041
0-1	.266	.298	.032
0-2	.200	.223	.023

In retrospect, this seems like it should have been more obvious to me. A guaranteed reach of first base is very valuable to the offense (represented here as a .690 wOBA on a walk), and so the most damaging time for a pitcher to throw a ball is when there are already three balls. The ball count drives the difference in this table, so much so that throwing a ball in a 0-0 count to fall behind a batter is actually less damaging for a pitcher than throwing a ball in a 1-2 count, a count in which many pitchers seem content to “waste” a pitch to set the batter up later in the at-bat.

There is a major gap in the wOBA change following a ball between one-ball counts and two-ball counts, and that line happens to be extremely important for Bauer. Among qualified starters, Bauer has seen the biggest improvement in his strike rate in two-ball and three-ball counts compared to last season.

Biggest 2 and 3-Ball Count Strike Rate Improvers, 2016

Pitcher	2015	2016	Improvement
Trevor Bauer	67.3%	74.2%	6.9%
Mike Fiers	72.0%	78.8%	6.8%
Noah Syndergaard	75.2%	80.3%	5.1%
Collin McHugh	72.5%	76.9%	4.4%
Mike Leake	71.9%	76.3%	4.4%
Gio Gonzalez	69.3%	73.4%	4.1%
Tom Koehler	65.9%	69.0%	3.1%
Clayton Kershaw	77.3%	80.1%	2.8%
Jon Niese	68.2%	70.9%	2.7%
Julio Teheran	70.6%	72.9%	2.3%
Taijuan Walker	74.6%	76.8%	2.2%
Rick Porcello	74.9%	77.0%	2.1%

The list features some starters who are enjoying bounce-back seasons, such as Julio Teheran and Rick Porcello. Looking back at the leaders since 2003, several leaders sustained their command improvements and became elite starters, such as Kershaw in 2011, Cliff Lee in 2005, and Brandon Webb in 2005.

Biggest 2 and 3-Ball Count Strike Rate Improvers, 2003-16

Pitcher	Season	Improvement
Brandon Webb	2005	10.5%
Jeff Samardzija	2014	7.8%
Carlos Silva	2005	7.3%
David Wells	2003	7.2%
Trevor Bauer	2016	6.9%
Mike Fiers	2016	6.8%
Roy Halladay	2003	6.5%
Ervin Santana	2008	6.3%
Clayton Kershaw	2011	6.2%
Cliff Lee	2005	5.7%
Ted Lilly	2009	5.5%
Bruce Chen	2012	5.3%

The major question with Bauer is whether his improved control in the most critical counts is the result of actual mechanical—or possibly strategic—improvements or whether it is random. For fantasy purposes, I’m willing to bet on the former, especially given that Bauer’s groundball rate has increased from 39.2 percent to 46.8 percent this season, a possible indicator of a new pitch-to-contact approach. Trading in a handful of strikeouts for many fewer walks could be the key to Bauer reaching his potential. And with the quality of stuff Bauer continues to have, fantasy owners should invest.