Pittsburgh Pirates Starting Pitchers: Bauer Units


The Pittsburgh Pirates rotation is essentially set, there is still a question on the five starter, who in all likelihood will be either Trevor Williams or Tyler Glasnow.  The team throws hard, but most don’t throw the fourseam, for what reason?

Kyle Boddy and Driveline Baseball study pitching, they train athletes, and some Pirates have trained there in the past, including Tyler Glasnow this offseason.  They focus their efforts using data to train the pitchers.  They’ve constructed a relatively simple method, called Bauer Units.  The equation is easy to calculate, all you need is the information from baseball savant, and take the spin rate (rpm) and divide it by the velocity (mph).  They mention:

"“The general idea when discussing fastball spin rate is that the MLB average is a 92 mph fastball spinning at 2200 rpm. This makes the average Bauer Unit 23.9, which can be rounded to 24.”"

The general idea and the baseball savant numbers don’t match perfectly, as you can see in Driveline’s post, but 24 Bauer Units is essentially average in both.  After downloading the data from baseball savant, we can take a look at the Pirates pitchers 2016 velocities and spin rates on their fourseam fastball, and then calculate their Bauer Unit.

PitcherResultsMPHRPMBauer Unit

The Pirates don’t have any pitchers with above average Bauer Units (24), as Jameson Taillon and Ivan Nova are both essentially average (Nova is right at average with Baseball Savant’s data).  Also keep in mind that Trevor Williams sample is even below the sample size that Driveline used in their measures. But what does this mean and how should pitchers attack?  Driveline provides the answer:

"League average Bauer Units -> look into developing a 2-seamAbove average Bauer Units -> try to throw middle/up in the zoneBelow average Bauer Units -> try to throw middle/down in the zone"

Jameson Taillon started throwing a two seam fastball right before he reached the Major Leagues, as Adam Berry of MLB.com wrote:

"“Before his second-to-last start in Triple-A, Taillon met with pitching coach Stan Kyles, pitching coordinator Scott Mitchell and assistant GM Kyle Stark to talk about his pitch selection. Primarily a four-seam fastball pitcher, Taillon always threw a two-seamer as a situational pitch, a weapon to be deployed in specific situations.But the Pirates’ pitching brain trust presented Taillon with the data. Hitters were missing his two-seamer more often; when they did make contact, they were more likely to hit a ground ball. The pitch made him more efficient.”"

Taillon used his two seam fastball 39.55 percent of the time last season, compared to just the 23.23 percent on his fourseam.  He scratched the pitch with an average Bauer Unit in favor of the two seam and excelled.

Mar 5, 2017; Tampa, FL, USA; Pittsburgh Pirates starting pitcher Jameson Taillon (50) throws a pitch during the first inning against the New York Yankees at George M. Steinbrenner Field. Mandatory Credit: Kim Klement-USA TODAY Sports
Mar 5, 2017; Tampa, FL, USA; Pittsburgh Pirates starting pitcher Jameson Taillon (50) throws a pitch during the first inning against the New York Yankees at George M. Steinbrenner Field. Mandatory Credit: Kim Klement-USA TODAY Sports /

Ivan Nova relied on his fourseam fastball early on in his career.  He used the pitch 55.11, 55.27, 49.4, and 34.93 percent of the time from 2010-13.  In 2015 and 2016 he only threw the fourseam 18.18 percent and 11.08 percent of the time.  He changed to the two seam in 2015, throwing it 47.16 and 51.30 percent the last two years.  With the Pirates, Nova threw the two seam at a rate of 54.51 percent, and he posted a 3.06 ERA and 2.62 FIP for the club.  The two seam did wonders for him.

Tyler Glasnow also possesses an average Bauer Unit on his fastball, and he relied on the pitch 63.07 percent of the time last season.  That appears like it could change this season, as Stephen Nesbitt of the Pittsburgh Post-Gazette wrote:

"“This spring, Glasnow has added a two-seam fastball and workshopped a new changeup grip — switching from a four-seam to a two-seam grip.”"

Will the change help?  That remains to be seen, but the path he is going follows what Boddy said.

That gets us down to Chad Kuhl, who has a below average Bauer Unit, but he only threw the pitch 10.17 percent of the time last season, and when he did throw the fourseam, 62 percent of them were middle of the zone or below.  Kuhl relies on his sinker, which he throws low in the zone to get groundballs.

Gerrit Cole relies on his fastball, throwing it 59.36 percent of the time last season.  His 22.85 Bauer Unit is below average, meaning Cole should work middle down.  He does so, as 701 of his 1151 fourseam fastballs (61 percent) were thrown middle to low.

Next: Predicting Opening Day Roster

That leaves Trevor Williams, who has the lowest Bauer Unit on his fourseam at just 21.04.  He also has the smallest sample, just 88.  Trevor threw his fourseam 39.29 percent of the time and he threw a sinker 28.13 percent.  At 94 miles per hour, Williams should be able to stay with the fourseam, he just has to keep the pitch low.  51 of his 88 (57.95 percent) fourseams were middle to low, and just 40 (45.45 percent) were low.  In 2017, if he keeps the ball low he should have more success than a 7.82 ERA and 6.70 FIP despite those coming in the smallest of small samples.

The Pirates love to throw the two seam fastball and work low in the zone.  This helps, perhaps, quantify the Pirates strategies as they have low to average Bauer Units on their fourseam fastballs, with their starters anyway.

*Data from Baseball Savant