Expected Value exists because quantitative thinking shouldn't be locked behind academic journals and finance textbooks. The ideas on this site — probability, expected value, decision theory, cognitive biases — are some of the most practically useful concepts ever developed. Yet most people never encounter them outside a university lecture hall.

I started this site after years of applying these concepts professionally in investing and strategy consulting. I kept finding that the same mental models — base rates, expected value calculations, Bayesian updating — gave me an unfair advantage in almost every domain. Not because I was smarter than anyone else, but because I had a better framework for thinking about uncertainty.

The goal here is simple: explain these ideas clearly, without unnecessary jargon, and show how they apply to real decisions. Every article is written to be useful on first read and worth revisiting. If you finish an article and think differently about a decision you're facing, I've done my job.

• Probability & Expected Value — Core mathematical frameworks for reasoning under uncertainty
• Decision Science — How to make better choices when outcomes are uncertain
• Cognitive Biases — The systematic errors in human thinking, and how to correct for them

The world is not driven by greed. It's driven by envy. And it's not driven by malice. It's driven by stupidity. The correct response to both is the same: think in probabilities, not narratives.

— Adapted from Charlie Munger