Thinking books · Probability & quantitative thinking · Leonard Mlodinow, 2008

The Drunkard’s Walk — the big ideas

How randomness shapes outcomes people confidently attribute to skill.

Free — no account needed to read

The big ideas

Streaks and patterns occur in genuinely random sequences far more often than intuition allows, so most "hot streaks" require no explanation.

Regression to the mean explains an enormous amount of apparent cause and effect — including why punishment seems to work and praise seems to backfire.

Small samples produce extreme results, which is why the best and worst performers are so often the smallest groups.

Practise it — no need to have read it

Find a recent unusually good or bad result in your work. Ask what would happen next if nothing changed at all.

A hint: Usually: something closer to average. Act on that before attributing a cause.

Where it shows up in real life

• Performance review
• Reading your own metrics
• Evaluating a run of results

Described in our own words with the source named — never quoted, and not a substitute for reading the book.