Last with Washington Nationals · C · No longer on a 40-man roster
Spencer Kieboom has an estimated 150 days of major league service time — 0.150 in the notation clubs use, from 150 days credited on a major league roster.
| Season | Club | Days | Running total | How this season is known |
|---|---|---|---|---|
| 2016 | Washington Nationals | 6 | 0.006 | From transactions |
| 2017 | Washington Nationals | 0 | 0.006 | From transactions |
| 2018 | Washington Nationals | 144 | 0.150 | 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.