Some people come to decision-making by studying it.
I came to it by living it.
Across six careers, four decades, and more uncertainty than any framework could have prepared me for, I learned something simple: life rarely gives you perfect information before it asks you to decide.
The Mathematician Who Beat the House
In my teens I discovered I had a gift for mathematics. Not the classroom kind. Rather, the applied kind. The kind that lets you look at a system, understand its structure, and find the edge hiding inside it.
In my twenties I became a professional card counter. I beat the house, legally, at a time when few people understood the mathematics well enough to do it consistently. Eventually the casinos noticed. And instead of banning me, one of them hired me.
For five and a half years I worked at Bally’s Park Place Casino in Atlantic City as one of their in-house mathematical experts. I sat on the other side of the table and understood probability from both directions. That work later led to me being recognized by courts as an expert witness in the mathematics of gambling, a credential I carry to this day.
The Pioneer
In 1982 I founded something that had never existed anywhere in the world: a home in the community for brain injury rehabilitation.
There was no model to follow. No roadmap. No guarantee it would work. Just a belief that people with traumatic brain injuries deserved something better than institutional care. With two co-founders, I had the willingness to build it from nothing.
We built it. And then we became the first facility of its kind to receive full accreditation. The company was sold in 1990. It remains one of the things I am most proud of.
The Horseman
After selling the company I did something that surprised people who knew me as a mathematician and businessman.
I started a farm to rescue injured and retired thoroughbred racehorses.
No probability formula. No strategic framework. Just compassion for animals that had given everything and deserved a dignified life after the track. That chapter taught me things about patience, care, and uncertainty that no boardroom ever could.
The Business Builder
After my health forced me to slow down just a little, I didn’t stop working. I became a business consultant, helping companies grow, analyzing them from the ground up, and preparing them for sale.
The work suited everything I had learned across five careers. I could see a business the way I once saw a card table, as a system with hidden structure, exploitable edges, and risks that weren’t always visible to the people inside it.
One engagement stands out. I joined Halco Service Corporation when it was doing approximately $1.5 million in annual sales. Over the next five years we grew it to over $10 million per year in revenue with an amazing margin. The company made the Inc. 5000 list of fastest-growing privately held companies all five years during that period. The company was sold in 2023 for a handsome premium.
That is what applied probability thinking looks like in a business context. Not theory. Not a framework from a book. Just a clear understanding of where the real risks were, where the real opportunities were, and how to make decisions that compounded in the right direction.
The Writer
After my health improved, I did what I had been thinking about for years.
I started writing down what I had learned.
Not theory. Not research. The actual structure of how decisions behave when you cannot see clearly, drawn from five decades of operating in environments that did not offer clean feedback, guaranteed outcomes, or the luxury of waiting for certainty before acting.
Four books later, I am still writing. And I believe the most important chapters are still ahead.
Why This Matters for You
I did not write these books because I figured everything out.
I wrote them because I spent forty years making decisions in conditions where the standard advice did not apply and I wanted to give you something more honest than most self-help offers.
Not a promise that life will make sense.
Not a system that eliminates uncertainty.
Just a clear-eyed framework for operating well inside it.
That is what every book I write is trying to do.
And it starts with everything I lived before I wrote a single word.
Gary Levin is the author of four books on probability, decision-making, and uncertainty. He lives in Mays Landing, New Jersey.