Pittsburgh Pirates: Examining How Trevor Williams Has Bounced Back

After struggling in the final three months of the 2019 season, Trevor Williams appears to be back on track for the Pittsburgh Pirates.

Over the course of the first 65 starts of his MLB career, Trevor Williams appeared to blossoming into one of the better starting pitchers in the National League. In these 65 starts, Williams posted a 3.47 ERA and a 3.81 FIP across 368.1 innings pitched for the Pittsburgh Pirates.

Following a start against the San Diego Padres on May 16th, 2019, William went on the injured list with an oblique issue. He would return on June 20th, but went on to struggle for the remainder of the season. In his final 16 starts of 2019, Williams posted a 6.23 ERA and a 6.17 FIP across 86.2 innings of work.

So, what went wrong for Williams in these 16 starts? Well, the biggest issue for Williams was a lack of soft contact. When Williams is at his best batters are late on his fastball and he is inducing soft contact. During that tumultuous 16 start stretch last season, Williams allowed hard contact at a 30% rate, induced soft contact just 18.8% of the time, and opposing batters had an average exit velocity of 88.5 MPH against his pitches.

As a result of an increase in hard contact allowed, Williams also saw an increase in home runs allowed. He allowed 21 home runs in these 16 starts, which came out to a home run rate of 2.18 HR/9. During his tremendous 65 starts stretch, Williams allowed home runs at a rate of just 0.77 HR/9.

So far in 2020, Williams has made five starts. In these five starts his ERA is 3.70 and his FIP is 4.22. A big reason why 2020 has been a bounce back season thus far for Williams is that he is back to inducing soft contact at a high rate, while cutting down on hard contact allowed.

His soft contact rate has jumped 5% to 23.6%. Meanwhile, his hard contact rate has dropped from 30% in his final 16 starts of 2019, to 26.4% so far in 2020. Also, the opposing exit velocity against Williams has dropped to 85 MPH. 85 MPH is more than 3 MPH lower than the league average of 88.2 MPH.

Opposing batters are also barreling the ball and a much lower rate than in years past. So far in 2020, opposing batters are barreling the ball against Williams just 1.4% of the time. This puts him in the 90th percentile of baseball. Trevor’s previous career low barrel rate was 5.2% in 2017.

With a drop in hard contact, exit velocity, and barrel rate, Williams has also experienced a drop in home runs allowed. His home run rate this season has dropped from over 2.00 HR/9 in his final 16 starts of 2019, to 1.11 HR/9 through his first five starts of 2020. While you would still like to see that number drop a bit, it is certainly a huge improvement over the 2.18 HR/9 number he had in his final 16 starts of 2019.

A driving force behind these improved rates for Williams has been a change in pitch usage. Last season, Williams threw his four-seamed fastball 51.9% of the time. This season, he has thrown the pitch just 44.2% of the time. His slider usage has gone from 20.1% to 24.3%, and he has gone from barely throwing a curveball to having thrown it 6.2% of the time this season.

The slugging percentage off of Williams’s fastball has dropped from .509 in 2019 to .340 in 2020. Opposing batters are slugging .579 off of his slider, however, it has still provided plenty of production for William as the pitch has a 41% whiff rate. While he has only thrown the pitch 27 times, he has yet to allow a base hit off of his curveball.

The spin rates on his pitches are also up over last season. His four-seamed fastball spin rate has gone from 2203 in 2019 to 2270 this season. The spin rate on his slider has gone from 2202 to 2273, and from 2259 to 2281 on his curveball.

Williams has also been able to effectively use his change up against left-handed hitters. Last season, 85.4% of the change ups he threw were against LHHs. In 2020, 93.4% of the change ups Williams has thrown have been against LHHs.

His change up has an exit velocity of just 85.2 MPH, to go with a .313 slugging percentage. The pitch has also generated a 22.9% whiff rate. The change up is a big reason why LHHs are hitting for a .234/.290/.313 slash line against Williams, after slashing .335/.391/.561 against Williams in 2019.

So far in 2020, Williams has looked like the pitcher he was in his first 65 MLB starts. After struggling in his final 16 starts of 2019, driven by a change in pitch usage and a drop in hard contact allowed, Williams appears to be back on track as being one of the most underrated and underappreciated starting pitchers in the NL.