Last with San Francisco Giants · C · No longer on a 40-man roster
Buster Posey has an estimated 11 years and 163 days of major league service time — 11.163 in the notation clubs use, from 2055 days credited on a major league roster.
| Season | Club | Days | Running total | How this season is known |
|---|---|---|---|---|
| 2009 | San Francisco Giants | 35 | 0.035 | From transactions |
| 2010 | San Francisco Giants | 128 | 0.163 | From transactions |
| 2011 | San Francisco Giants | 172 | 1.163 | From transactions |
| 2012 | San Francisco Giants | 172 | 2.163 | Carried forward |
| 2013 | San Francisco Giants | 172 | 3.163 | Carried forward |
| 2014 | San Francisco Giants | 172 | 4.163 | Carried forward |
| 2015 | San Francisco Giants | 172 | 5.163 | Carried forward |
| 2016 | San Francisco Giants | 172 | 6.163 | Carried forward |
| 2017 | San Francisco Giants | 172 | 7.163 | From transactions |
| 2018 | San Francisco Giants | 172 | 8.163 | From transactions |
| 2019 | San Francisco Giants | 172 | 9.163 | From transactions |
| 2020 | San Francisco Giants | 172 | 10.163 | From transactions |
| 2021 | San Francisco Giants | 172 | 11.163 | 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.