One Model at A Time

In 1935, Boeing's most advanced bomber stalled and crashed on takeoff — not because the plane was bad, but because the pilot forgot a simple step. The answer was a checklist. Today's mental model: when a job has more steps than memory can hold, don't trust memory — write it down. From pilots to a short surgical checklist that cut deaths in a worldwide study, the humble list beats the expert brain.

One Model at a Time is a Thousand Bagger show. New episodes daily.

Ice cream sales and shark attacks rise and fall together — so does ice cream cause shark attacks? Of course not; summer causes both. Today's mental model is correlation versus causation: two things moving together doesn't mean one causes the other. Plus a stock market predictor based on butter production in Bangladesh, and why investors keep falling for the same trick.

One Model at a Time is a Thousand Bagger show. New episodes daily.

An investor gains 30 percent a year for five brilliant years, then loses 100 percent in year six. Final result: zero. When things multiply together, one total loss erases everything that came before. Today's mental model is multiplicative systems — and why avoiding the zero matters more than chasing the big win. Plus how one investor's fortune of about 20 billion dollars was reportedly wiped out in a matter of days.

One Model at a Time is a Thousand Bagger show. New episodes daily.

A disease affects one person in a thousand. A test catches every real case but gives a false alarm one time in a hundred. You test positive — what are the chances you actually have it? About nine percent, not ninety-nine. Today's mental model is Bayesian updating: start with how likely something is, then adjust as each new piece of evidence comes in. Plus why Warren Buffett, famous for holding stocks forever, sold every airline share he owned within weeks.

One Model at a Time is a Thousand Bagger show. New episodes daily.

People love to say they don't build them like they used to. But the old buildings you see are only the ones that survived — the ugly and badly built ones were knocked down long ago. Today's mental model is survivorship bias: before you learn from the winners, ask who's missing from the picture. From Abraham Wald's Second World War bombers to the investment funds that quietly disappear, the winners are visible and the losers are silent.

One Model at a Time is a Thousand Bagger show. New episodes daily.

A finance professor studied 26,000 American stocks over 90 years and found that about four percent of them created all the net wealth in the stock market. Today's mental model: power laws and fat tails. In some areas — wealth, book sales, city sizes, venture returns — a few extreme outcomes matter more than all the ordinary ones put together. We walk through Accel's $12.7 million bet on Facebook and what it teaches every investor.

One Model at a Time is a Thousand Bagger show. New episodes daily.

People beat the casino every single night — so how does the house always come out ahead? Today's mental model is the law of large numbers: over many tries, the average settles toward the true odds. From the two green slots on a roulette wheel to Jacob Bernoulli's 1713 proof to how an insurer like GEICO prices millions of drivers it knows nothing about — small samples can say almost anything, but large samples tell the truth.

One Model at a Time is a Thousand Bagger show. New episodes daily.

Athletes land on the cover of Sports Illustrated — then slump. Is the cover jinxed, or is something deeper at work? Today's mental model is regression to the mean: when luck plays a part, extreme results tend to be followed by more ordinary ones. We trace it from a student who scores 95 after a lucky day, to Francis Galton's tall parents, to why last year's star fund manager so rarely repeats.

One Model at a Time is a Thousand Bagger show. New episodes daily.

Your friend opens a restaurant with great food and a great location. What are the odds it's still open in three years? Before you answer, learn the mental model called base rates: your starting guess for your own case should be how things usually turn out for cases like it. We walk through a famous restaurant study and Daniel Kahneman's eight-year textbook project — the time he forgot to check the base rate and paid for it.

One Model at a Time is a Thousand Bagger show. New episodes daily.

With two cases left — one holds a dollar, the other a million — the banker offers four hundred thousand. Should you take it? Enter decision trees: mapping your choices, their chances, and their outcomes so you can see the whole decision at once. Including the reason most lawsuits never make it to a courtroom.