Last with San Francisco Giants · LF · No longer on a 40-man roster
Mac Williamson has an estimated 2 years and 7 days of major league service time — 2.007 in the notation clubs use, from 351 days credited on a major league roster.
| Season | Club | Days | Running total | How this season is known |
|---|---|---|---|---|
| 2015 | San Francisco Giants | 19 | 0.019 | From transactions |
| 2016 | San Francisco Giants | 130 | 0.149 | From transactions |
| 2017 | San Francisco Giants | 69 | 1.046 | From transactions |
| 2018 | San Francisco Giants | 65 | 1.111 | From transactions |
| 2019 | Seattle Mariners, San Francisco Giants | 68 | 2.007 | 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.