The intriguing case of Stephen Tarpley

UPDATE

Tarpley (right oblique strain) was placed on the 10-day injured list Monday afternoon with a right oblique strain. There’s currently no timetable for his return.

Stephen Tarpley has been one of the standout pitchers in the Marlins bullpen. When you look at his profile, you won’t find a huge repertoire. Probably, the high 5.59 ERA he carried through Saturday won’t make you fall in love with him. But the 27-year-old, whose numbers go beyond that, has found success in 2020.

Acquired from the Yankees via trade back in January, Tarpley registers 9 ²⁄₃ innings of nine-hit, six-run ball. He’s given up five walks and struck out 10, with a 1.45 WHIP and a 4.60 FIP.

But you gotta go deeper to appreciate what the lefty has done so far. If you’re bothered about his high ERA, let me tell you it would be at 2.00 if it wasn’t for his August 18 appearance against the Mets (four earned runs in two-thirds of an inning). He has helped more than hurt when considering the game context, contributing 0.2 Win Probability Added this season according to Baseball-Reference.

What has impressed me the most about his first 10 outings in 2020 is his results despite his limited repertoire. Tarpley essentially throws only two pitches: a 90.8 MPH sinker and a 78.8 MPH curve, which he uses 33.8 percent of the time.

It’s his curveball that is the key weapon for him here. Opponents are hitting for a .167 average of that pitch (2-for-12), and the California native has recorded nine of his 10 punchouts with that delivery.

Based on his curve, Tarpley—who begins counts with a strike in 67.4% of times—has been dominating to a very particular level. This man, who does not have overwhelming velocity, is pitching with craftiness and is inducing soft contact as his exit velocity is below the MLB average (87.4 MPH for Tarpley compared to 88.2 MPH across MLB).

Tarpley’s pitching style allows him to get a good quantity of ground balls. In fact, his launch angle is at just 4.2 degrees while his GB% rate sits at 53.8%. At the same time, he does not allow many line drives (15.4%).

The real stuff is on his batted ball profile besides his ground ball tendencies. 11.5% of the balls put in play by his opponents qualify as “weak” by Baseball Savant, that is, any batted ball under 60 MPH—MLB average is 3.1%!!!

Another incredible thing is that, somehow, he’s making hitters fail by getting on top (38.5%) or under balls (26.9%) at a higher rate than MLB average. Even better, his solid contact rate is at 0.0% and his barrel% is at 3.8% (6.3% MLB average).

Tarpley has been a really good, useful option for Don Mattingly. Controllable for the Marlins through at least the 2025 season, it seems he can—health permitting—keep this up in the long term, along with pieces like Alex Vesia, Jeff Brigham, and company.