Day 14 · Act III — Lead Performance
Decision-Making Under Uncertainty
Probability · Biases · Decision journals
~30 minutes
A good decision can have a bad outcome; judge the thinking, not just the luck.
The Core Idea
Leaders rarely have complete information. The quality of a decision lies in the process: what you knew, how you weighed it, what alternatives you considered.
Annie Duke calls the error of judging decisions by outcomes 'resulting'. A decision journal breaks this habit by recording reasoning before results are known.
The Mental Model
Decision Journal
Before deciding, record the context, options, expected outcome with probability, and how you feel. Review later.
At work: '70% confident the new pricing increases revenue within two quarters. Key risk: churn among small clients.'
The Case Study
The Bay of Pigs vs the Cuban Missile Crisis
DocumentedThe same Kennedy administration made the failed Bay of Pigs decision (1961) and navigated the Cuban Missile Crisis (1962).
Interpretation: historians often attribute the improvement to a redesigned process that invited dissent — a lesson in groupthink.
Cinema & Story
The Big Short (2015)
Seeing what the crowd ignores requires independent data and the nerve to act on probability.
The Reading Room
Thinking in Bets
Annie Duke
How to make better decisions when you lack all the facts.
Further reading: The Undoing Project — Michael Lewis
The Journal · Portfolio output: Decision journal
The Field Experiment · within 24 hours
Before your next significant decision, write your probability estimate and one reason you might be wrong.
The Evening Review
Think in probabilities; act with conviction.