Meaning 1 ►▼
For the football term "quarterback" go to that idiom. Fans replaying a play after the fact.
Tom Brady, the quarterback of the New England Patriots, threw a pass for a touchdown but the play was reviewed by news media later.
Meaning 2 ►▼
To decide what could have happened after the fact. Hindsight.
Avid football fans frequently are "Monday morning quarterbacks," reviewing their teams' play.