Nick Pivetta has simplified it in the bullpen

It’s a common sight to see. Contending teams run out low-performing starters with a short leash, come to a decision to send said starter to the bullpen, and discover potential value with a shift in roles. The Phillies and Nick Pivetta have recently ran into this exact scenario.

Up until this season, Nick Pivetta had been a serviceable starting pitcher at the major league level. While his surface stats weren’t eye-popping (ERAs of 6.02 and 4.47 in 2017 and 2018 respectively), his underlying stats justified the potential upside (FIP’s of 4.87 and 3.80).

Pivetta struggled to positively contribute early in the season, as his ERA for the month of April was a putrid 8.35. He quickly picked-up his performance though, albeit with a declining strikeout-rate and increasing walk-rate...it became harder to make up excuses for the raw results.

At the conclusion of the first half, Pivetta ranked 122 of of 131 in ERA for all starting pitchers with at least 60 innings. His FIP ranked 126th and his xFIP ranked 80th. With the Phillies walking a tightrope in a crowded National League wild card race, along with the prospect of incoming acquisitions before the trade deadline, the time to move Pivetta to the bullpen had arrived.

The early results for Pivetta in the bullpen have been more than encouraging. Among 98 relievers with at least 10 innings in the second half, he ranks...

• 29th in ERA
• 37th in FIP
• 10th in xFIP
• 12th in SIERA
• 12th in K-BB%

Since moving to the bullpen, Pivetta has seen an increase in strikeouts, a decrease in walks, as well as a large increase in ground balls and decrease in hard-contact. Much of this can be attributed to the obvious improvement that comes with most moves to the bullpen: fastball velocity. He’s now reached a level in the bullpen that he hasn’t reached since earlier this season.

FanGraphs

Another significant change has taken place for Pivetta in his new role. Pitching as a starter, he was required to use a deeper repertoire, mixing in am average slider (.286 xwOBA) and below-average sinker (.558 xwOBA).

FanGraphs

By moving to the bullpen, Pivetta has been able to focus on throwing his best secondary offering—a high-spin curveball, which paired with his added fastball velocity has been a recipe of success. Per 100 pitches, the run value on Pivetta’s fastball has jumped from -1.70 to -0.17 in his role change. The run value on his curveball 0.04 to 2.28. Pairing the two pitches, the only two pitches in his relief repertoire, has helped the value of both offerings.

For a Phillies bullpen that ranks 24th in ERA and 27th in FIP for the season, any addition that has a chance to add value to a team in the middle of playoff race is substantial. Though the sample size has been small, Nick Pivetta has the early showings of that critical piece.

Patrick Brennan loves to research pitchers and minor leaguers with data. You can find additional work of his at Royals Review and Royals Farm Report. You can also find him on Twitter @paintingcorner.