Human behavior and game theory collide in the world of ride-sharing with friends.

Am I about to make ride-sharing less fun? Probably. Party on!

In my last blog post I combined two well known game theory exercises (the Unscrupulous Diner’s Dilemma and the Pirate game) into a new puzzle: the Pirate’s Diner Dilemma. The aim of the problem was to illustrate how the rationally optimal outcome differs from the solution expected from social norms.

Many friends questioned whether they wanted to dine with me again (I hope jokingly!). Others asked whether there was any practical use to the thought experiment. Wouldn’t all diners end up behaving based on emotion, psychology, and culture (i.e. splitting a check evenly) versus trying to be strategic and sneaky…


It’s best to think critically when dining with Captain Barbossa and other pirates.

How to make your next dinner more interesting?

Another COVID weekend spent indoors as I wait for vaccine shots to release me from social isolation — sigh. What better way to use the time than dream about all the dinners with friends in the near future? As a conversational emcee of sorts, it’s time for me to start thinking of ways to make these dinners memorable. For this blog post, I’ve decided to make my next dinner spicier with some game theory flavoring.

I’ve recently been reading Israeli mathematician Haim Shapira’s game theory book Gladiators, Pirates and Games of Trust: How Game Theory, Strategy and Probability Rule Our…


The proposal for a employee-friendly TREE security

TL;DR — Join me for a thought experiment

Equity ownership is a zero sum game. Companies would prefer to retain equity value for shareholders (e.g. employees) who contribute creative capital rather than continuously pay an equity “tax” to already enriched early investors whose capital contributions no longer have meaningful impact on the business. The introduction of a new security type–the TREE –could cap early investor returns at pre-determined thresholds and free up cap table value for employees, providing a potential win-win solution. This instrument would likely not work for the structures of current early stage and venture capitalist investors, but could…


Reading — perhaps this year more than ever — became an outlet. Books helped me explore, understand, and escape the reality of life during a pandemic.

It’s hard to summarize neatly what it’s been like to live through 2020. When the countdown on 2019 finished, the year started off much like any other — full of the usual promise and anticipation. In my review of 2019 books I read, I noted my optimism to spend much of 2020 in creation mode, including writing more.

In the early 2020 months life was mostly normal with the worst news being Australian bushfires…


I was bored during COVID-19 shelter-in-place, so I invented a mathematical law dealing with probabilities. I was deprived of enough human contact that I named it after myself.

The inspirational spark

I recently witnessed the following conversation between two friends on Zoom:

Friend #1: “Imagine I roll a six-sided die. What is the probability of rolling a 6?”

Friend #2: “One in six.”

Friend #1: “What if I rolled two dice?”

Friend #2: “Your chances would double. So two in six.”

Friend #1: “By that logic, if I rolled six dice, I’d have six times a one in six chance…


Fans at the 2014 FIFA World Cup. Photo: Getty.

Want to get into football but feeling stuck?

I love watching football. Yes, I’ll call it football in this blog post, since that’s what everyone outside the US calls it. There’s a reason it’s called “the beautiful game.” It’s fun, exciting, international, and full of traditions.

In the US, I often struggle to get friends as excited about football as I am. These friends are sports fans — they follow baseball, basketball, American football, hockey, tennis, golf, etc. While their sports itch might already be scratched by these other wonderful sports, I also hear regularly: “I’d love to get more into soccer, but I just don’t understand everything…


Based on an analysis of ESPN’s player ratings through the season, I have an answer: Mane. Van Dijk. Salah. In that order.

Liverpool forward Sadio Mane, photo from PSG Talk.

The wait for a trophy is over.

Liverpool just marched through one of the most impressive seasons in Premier League history. Over the course of the season they amassed a staggering 99 points, one shy of the record 100 point mark set by the 2017–18 Manchester City team. They wrapped up the title with a record 7 games remaining, giving Liverpool fans plenty of time to celebrate their first league title since 1990 and ending a 30 year…


No size fits all teams, but all teams have an ideal size. You should know yours and build around it.

By: Ry Sullivan

Building teams is important — but what does that mean?

To build a great business, you need a great product.

To build a great product, you need a great team.

To build a great team, you need the right people.

It seems like a very simple model at the heart of many company-building discussions. In fact, the late former CEO of General Motors Jack Welch once told me: “The team with the best players wins” as a mantra for how to succeed in business.

But who are the right people? And how do you structure them into a great team?

While there’s much written about hiring and…


What I learned from my 2019 resolution to read a book per week

Similar to many people, I started off 2019 with a list of resolutions. The goal as always was self-improvement and self-investment. Some goals, like beating my best 5K running time, didn’t happen (or come particularly close). One ambitious goal — to read one book per week for the entire year — was accomplished.

Social media is filled with year-end reading lists, and I don’t expect this write-up to stand out in a crowded field. I’m also aware that there is a sort of perceived hubris in publishing…


If you live in San Francisco, you should buy a scooter. Period. Full stop. End of discussion. Since I’ve lived in the city, I’ve tried it all — owning a car, riding a bike, catching Muni buses and metros, taking Ubers, and walking. It was my scooter that changed the way I experienced the city though — at a fraction of the cost.

My 150cc Vespa has been the best purchase I’ve made in the Bay (pictured below). Skeptical? Many friends of mine have been, which is the inspiration for this post. I’ll highlight the benefits of owning a scooter…

Ry Sullivan

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