Pittsburgh Pirates: Chris Stratton’s Place in the Future of the Bullpen

The Pittsburgh Pirates are in the midst of a rebuild and a large amount of focus will be given to prospects in the Pirates’ farm system. However, a rebuild also relies heavily on talent at the Big League level. Chris Stratton has pitched more relief innings than any other Pirate this season, how important is he to the Pirates rebuild?

This series of articles will evaluate the current MLB-level pitching talent within the Pittsburgh Pirates organization with the sole purpose of trying to determine how that talent fits into the organization’s future. The first player we looked at was Sam Howard, this second article will focus on Chris Stratton.

Stratton was drafted in the 1st round of the 2012 MLB Draft by the San Francisco Giants and was a highly touted pitching prospect out of Mississippi State University. After a few relatively good seasons in the minors, Stratton would make his debut in 2016 out of the bullpen. Across 2017 and 2018 Stratton would start 36 games for the Giants and would pitch to an ERA of 4.63 with a relatively low 7.8 K/9 and a relatively high WHIP of 1.45.

At this point, Stratton had lost most of his value as a first round prospect and was traded to the Angels for Williams Jerez. After posting a 8.59 ERA with the Angels the Pittsburgh Pirates would get their shot with Stratton in late 2019.

The Pirates would turn Stratton around in the latter half of 2019 while having him pitch from the bullpen instead of the starting rotation. In 2019 Stratton would pitch 46.2 innings with the Bucs and post an ERA of 3.66, increase his K/9 to 9.1, and decrease his WHIP to 1.39. After this successful stint, Stratton would make the Pirates 2020 roster and further improved his numbers, pitching 26 innings with a 3.12 ERA, an 11.8 K/9 and a 1.23 WHIP.

Of course, these metrics don’t necessarily tell the full story. Let’s look at some advanced metrics and see if they support Stratton’s apparent success after moving to the bullpen and to Pittsburgh. To start, Stratton’s 2020 SIERA sits at 3.31, FIP at 3.23, and xFIP at 3.30 – handedly beating both ZiPS and Steamer projections. These line up well with Stratton’s solid ERA, suggesting that Stratton’s ERA is a true reflection of his season and that the righty has not been overtly lucky.

However, looking a little closer at Stratton’s contact data does raise some concerns. In 2020, Stratton has a hard hit rate of 38.2%, a barrel rate of 10.3% and a HR/FB rate of 14.3%. Hard hit rate is defined as baseballs hit with an exit velocity of 95 MPH or higher and barrel rate is defined as the percent of batted balls that have the exit velocity and launch angle that lead to a minimum .500 batting average and 1.500 slugging. These numbers are all on the wrong side of the league average for Stratton and suggest that he has been hit hard quite often this season.

So, why has Stratton been so successful?

A few things stick out to me. First, batters are chasing Stratton’s pitches at a higher rate than ever before in his career. On top of this, batters are straight up missing Stratton’s pitches instead of putting them in play. We already observed this with Stratton’s career high K/9, but Stratton also has career high whiff rate at 35.4% and career high chase rate at 30.9%.

Second, Stratton is inducing a crazy amount of ground balls this season. Stratton’s ground ball rate is sitting around 50% this season – which is up over 10% from 2019. For perspective, ground ball specialists Geoff Hartlieb and Jared Hughes have career 50.3% and 61.3% ground ball rates respectively.

Okay, so Stratton is getting more whiffs, chases, and ground balls in 2020. One would assume this is due to better off-speed pitches, however, Stratton’s secret weapon in 2020 has been his four seam fastball. Check out these crazy statistics:

2019 fastball spin rate – 2498 rpm

2020 fastball spin rate – 2617 rpm

2019 whiff rate 19.4%

2020 whiff rate 39.0%

2019 batting average against .293

2020 batting average against .171

Obviously, an increased spin rate and potentially other changes have made Stratton’s fastball unhittable this season. Now to be fair – there could be a lot of hidden statistics here that are not shown. For example, maybe Jacob Stallings calls pitch sequences that favor Stratton’s fastball, or perhaps Stratton is simply placing all of his pitches better this season. But, I can confidently say that something is up with his fastball and it is leading to a lot of success.

Just like Howard, Stratton has shown significant and meaningful improvement from 2019 to 2020. While Stratton may not have the raw stuff to be a closer, he can be a highly effective bullpen arm. Since Stratton is arbitration eligible through 2023, I would imagine that the Pittsburgh Pirates would plan on bringing Stratton back in 2021. With an extremely low expected team salary next season, arbitration money will probably not be a concern. With a strong start to 2021, Stratton could be one of the Pittsburgh Pirates more attractive trade pieces at the 2021 trade deadline.