The Solitaire Solution

Here’s something that will either comfort or disturb you: the mathematical technique underpinning your retirement strategy was invented by an unwell mathematician playing solitaire in his sick bed.

In 1946, Stanislaw Ulam found himself laid up recovering from encephalitis with nothing to do but shuffle cards. Being the sort of guy who couldn’t boil an egg without pondering the thermodynamics involved, he started wondering about the mathematical probability of winning at solitaire.

He tried working it out properly with equations and formulae, but the calculations became so complicated that he gave it up as a bad job. Then came his stroke of genius: why not just play the game hundreds of times and keep track of how often he won?

This novel “let’s just try it and see” approach caught the attention of John von Neumann, who realized it could solve their impossibly complex nuclear weapons calculations at Los Alamos. They needed a code name, and in a stroke of either genius or profound cheek, they called it “Monte Carlo” after the famous French casino.

That same technique, born from illness, boredom, and a deck of cards, now runs the projections for your retirement portfolio. Monte Carlo simulations test your life savings against thousands of possible futures: market crashes, raging inflation, and the possibility you’ll live to 105 complaining about the weather.

The old approach assumed markets would reliably deliver 7% returns every year, which anyone who’s paid attention to financial history will recognize as spectacularly optimistic. Markets don’t glide smoothly upward like a well-mannered escalator. They lurch about like a drunk on a trampoline.

Those colorful charts your financial advisor shows you, with squiggly lines fanning out like confused spaghetti? That’s Monte Carlo playing out every nightmare scenario so you don’t have to experience them in real life.

So next time you review your retirement plan, spare a thought for Stanislaw Ulam, a man who couldn’t simply play cards like a normal person, and whose boredom-induced revelation became the foundation for modern financial planning. Sometimes the most useful endeavors arise from the most unlikely circumstances and carry wonderfully tongue in cheek names.