Definition of washed (not exclusive or all-encompassing):

• benched (not due to injury) and never primary starter again

• retires

• starter but played badly (2015 Peyton Manning, but not 2022 Tom Brady)

Examples of how other legends would resolve

Peyton Manning: 2015 (Age: 39)

Tom Brady: 2023 (Age: 46)

Brett Favre: 2010 (Age: 41)

Johnny Unitas: 1971 (Age: 38)

Joe Montana: 1995 (Age: 39)

Drew Brees: 2022 (Age: 42)

John Elway: 1999 (Age: 39)

Dan Marino: 2000 (Age: 39)

Fran Tarkenton: 1979 (Age: 39)

Steve Young: 1999 (Age: 38)

Matt Ryan: 2022 (Age: 37)

Ben Roethlisberger: 2022 (Age: 39)

Philip Rivers: 2022 (Age: 40)

Aaron Rodgers: * (not yet, but may resolve to 2023 (Age: 40) if Rodgers is "washed" in 2024 and beyond)

Seems like 37-42 is a good benchmark with Brady an outlier at 46.

After the excercise of trying to resolve those players this is almost equivalent to asking when Patrick Mahomes will retire with exceptions for seasons like 2015 Peyton Manning where they are clearly one of the worst starters in the NFL and actively hurting their teams chances of winning. 2021 Ben Roethlisberger and 2022 Matt Ryan are edge cases where they definitely hurt their team, but aren't complete negatives. 2022 Tom Brady is somewhat confusing too due to his high volume passing stats but on mediocre efficiency, but the 49ers reportedly would've started him over Brock Purdy in 2023. In those cases I'll refrain from calling them washed unless they retire/get cut midseason as in Matt Ryan's case.