Teheran’s changeup was worth 2.5 pVAL in 2019. For the most part, it has average movement and decent velocity, but the true key to this pitch’s success is that he finally helped reduce the number of HRs Teheran gave up last year (11.8 HR/FB%, down 8.2% from 2018).
Teheran’s curveball was hit hard for a .357 AVG and a .936 OPS. Despite having gained nearly 2 mph of velocity, it lost several inches of movement, which may help explain its struggles.
Teheran’s fastball is the perfect example of how a pitcher can give up slightly below average contact (.808 OPS, 116 wRC+) and still put up positive pVAL (3.9), just so long as you pound the strike zone with it (58.7 zone%) and the good results outnumber the bad.
Teheran’s sinker was fantastic in 2019, wracking up an incredible 18.7 pVAL while holding opponents to a .187 AVG with a .515 OPS and a 48 wRC+. It succeeded in a large part without real standout peripherals. It had just enough movement to keep hitters off their toes when paired with his fastball.
Teheran’s slider gained 1.6 mph and actually saw decreases across the board in several of its key peripheral stats including movement, O-Swing% and SwStr%. It showed in the results as it was worth a rough -11.8 pVAL in 2019.
Teheran lost 1.5 mph on his average fastball velocity in 2018, and his four-seamer produced career-worst results in several categories. Interestingly, opposing hitters swung less than ever against Teheran’s fastball, even when thrown for a strike. When they did swing, however, batters posted a .237 ISO against Teheran’s fastball, the highest mark since his rookie year. If his fastball’s .236 BABIP regresses this year without other improvements, Teheran may want to decrease his fastball usage.
In 2018 Teheran lost velocity on his slider, but also gained horizontal movement. The results were excellent, as Teheran’s slider produced a 22.9% swinging-strike rate and allowed a .143 batting average against. Teheran only threw his slider in the zone 24.2% of the time, continuing a trend of a declining Zone% each year of his career. While a .207 BABIP is sure to regress, Teheran should feature his slider until opposing hitters adjust and stop chasing his slider out of the zone.
Teheran’s two-seamer produced excellent results in 2018 due to an improvement in home run suppression. His home run per fly-ball rate went from 22.9% in 2017 to 5.3% in 2018, and opposing batters produced a .043 ISO in 2018 compared to a .187 ISO in 2017. Outside of allowing a career-low 16.8% fly-ball rate on his two-seamer last year, not much else appears to have changed.
With a .105 BABIP allowed on his changeup, Teheran got excellent results from the pitch in 2018. Teheran threw the pitch in the zone less than ever before, with a 25.5% zone rate, and saw a jump in his swinging-strike rate to 10.1%. There doesn’t seem to be much different about the pitch, however, and it will likely remain a clear fourth option in his arsenal.
By far his worst pitch last year, Teheran’s curveball allowed a .478 AVG and a .652 ISO over 188 pitches thrown. Opposing batters only swung at his curve 28.7% of the time, and though he will likely benefit from regression with a .500 BABIP in 2018, there is little reason to throw it more often in 2019.