Learn and improve
Hindsight is unfair
Judge a past decision by what was knowable at the time, not by how it turned out.
Borrowed from the blameless postmortem practice in site reliability engineering, as described in Google's Site Reliability Workbook. Read the original source.
Ongoing habit · Minutes to start · Anyone on the team can start it
Try this first
Ask what we knew at the time, first, before anything else.
Use it when
Reviewing a past decision that looks wrong in hindsight.
Skip it when
This makes reviews fair, it does not excuse negligence where the risk was known and ignored. The test is what was knowable.
How to introduce it
Review a past decision against what the people knew when they made it. A call that looks obvious now often looked reasonable then, on the information available. Reconstruct that state of knowledge before you judge anything.
How to show up
Keep pulling the room back to what we knew then. Protect people from being judged for a reasonable call that turned out badly.
How long it takes
No setup. It's a discipline applied in reviews.
What makes it hard
Hindsight distorts hard, and rebuilding the earlier state of knowledge takes real effort. People also want someone to blame when things go wrong, which fights the reconstruction.
What it looks like when it's working
Reviews judge decisions by what was knowable, and people learn without being blamed for reasonable calls. Every bad outcome treated as an obvious error means hindsight is running the room.
How long until it sticks
A few reviews before reconstructing what-was-known-then becomes the reflex.
How you know it stuck
The team asks what was knowable before judging any past decision.
The idea behind it
Knowing the outcome makes the decision look more obvious than it was. Fair review rebuilds what was knowable rather than blaming people for missing what only became clear later.
Where it comes from
Blameless postmortem practice in engineering. A debrief norm that reconstructs what was knowable at decision time. A core rule: decisions that look wrong afterward often seemed reasonable at the time, so judge by what was knowable then.
Why it matters for senior teams
It shapes direction and consequential decisions