Last with Chicago White Sox · P · No longer on a 40-man roster
Michael Kopech has an estimated 6 years and 42 days of major league service time — 6.042 in the notation clubs use, from 1074 days credited on a major league roster.
| Season | Club | Days | Running total | How this season is known |
|---|---|---|---|---|
| 2018 | Chicago White Sox | 42 | 0.042 | From transactions |
| 2019 | Chicago White Sox | 172 | 1.042 | From transactions |
| 2020 | Chicago White Sox | 0 | 1.042 | From transactions |
| 2021 | Chicago White Sox | 172 | 2.042 | From transactions |
| 2022 | Chicago White Sox | 172 | 3.042 | From transactions |
| 2023 | Chicago White Sox | 172 | 4.042 | From transactions |
| 2024 | Los Angeles Dodgers, Chicago White Sox | 172 | 5.042 | From transactions |
| 2025 | Los Angeles Dodgers | 172 | 6.042 | From transactions |
172 days credit a full year, so a season adds at most 1.000 no matter how long a player is on a roster. 3.000 years reaches salary arbitration and 6.000 reaches free agency —
what every threshold unlocks.
This figure is an estimate reconstructed from public roster
transaction records. It is not an official MLB or MLBPA figure — those are
not published. See the
methodology.
Last updated 2026-10-12.
Independent project, not affiliated with or endorsed by Major League
Baseball or the MLBPA.