| Year | W | L | ERA | GS | IP | K | BB | WHIP | K/9 |
|---|---|---|---|---|---|---|---|---|---|
| 2024 | 5 | 8 | 3.99 | 20 | 99.0 | 38 | 33 | 1.29 | 3.44 |
| 2025 | 4 | 9 | 4.71 | 22 | 109.1 | 49 | 40 | 1.45 | 4.0 |
| 2026 ST | — | — | — | — | — | — | — | — | — |
The Sinker Was Working. Then the Elbow Gave Out.
Jack Kochanowicz opened 2026 in the rotation with a 3.10 ERA through his early starts — before the season unraveled to a 6.19 ERA over 13 starts and a right elbow problem put him on the 60-day IL in June. That number surprised people. The pre-season framing was clear: his ground ball rate (57.3% in 2024, third-best in the AL) is elite, but his K/9 (3.44, worst among qualified MLB starters) created a ceiling question that hadn't been answered. Through the first seven weeks, the sinker is doing what it's supposed to do at a higher level than the 2024 data predicted.
The circumstances helped. With Rodriguez on IL since Opening Day and Kikuchi shut down in early May with an arm issue, Kochanowicz went from fifth-starter competitor to rotation piece without an option. He took the spot, and for seven weeks the ground balls carried him. Then lineups adjusted to the sinker-heavy approach and forced the K-rate answer — the ERA finished at 6.19 over 64 innings before the elbow shut him down.
It did not hold. Lineups adjusted to the sinker-heavy approach exactly the way the pre-season analysis warned, the ERA climbed to 6.19 over 64 innings, and right elbow inflammation ended the experiment — 15-day IL on June 7, transferred to the 60-day on June 10. The second weapon never arrived. The K-rate question was answered, and the answer was the ceiling.