Write why before you act, and read it later to learn what was luck and what was thinking.
Keep a decision journal.
Your own results, played back. Again, or not again? Swipe.
Write the choice down when you make it. Judge it later by the reason, not the luck.
← Red LinesRed Line 46 of 48 The idea The scene Try it Where it bends This game’s numbersHow strong the proof isCMixed proof Where it comes from
Memory rewrites itself to fit what happened. A note written before you act keeps what you really thought, so the result can teach you the right lesson.
A planned monthly buy that fell, and paying off a 20% card in a good market year, were sound decisions with unlucky results. A hot tip that rose was luck. Judge by the note, not by the result.
Before your next money decision, write three lines: what, why, and what you expect. Read them a year later.
Rarely. It is the Red Start idea itself.
Your own games, on this device
The problem a journal fixes is well proven: once we know the result, we rewrite what we thought. That a journal fixes it has barely been tested.
- Hindsight ≠ foresight: The effect of outcome knowledge on judgment under uncertainty Baruch Fischhoff, Journal of Experimental Psychology: Human Perception and Performance 1(3), 288-299, 1975
- Thinking in Bets Annie Duke, Portfolio, 2018
Checked 2 Nov 2026 · How we grade
- A Strong proof: Many good studies or long official data, from different teams or countries, point the same way.
- B Good proof, with limits: Solid studies agree on the direction, but the size varies, or the data covers few places or few kinds of people.
- C Mixed proof: Some good studies for, some against, or the evidence covers only part of the line.
- D Thin proof: Mostly one book’s argument, one survey or stories. It may be wise, but it has not been tested well.
- = True by the sums: It follows from arithmetic, so no study can overturn it. We still show what real data says.
Annie Duke, Thinking in Bets (2018). In our words, not quoted.
See it in numbers: Hindsight (From Zero)
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