The 37% Rule


Hey friends,

I’ve just finished reading an incredible book called How to Not Die Alone by Logan Ury.

It was published earlier this year and it breaks down what trips people up when looking for love, and how to find and build lasting relationships.

There were a few bits from the book that blew my mind – one that I want to share today is framed around The Secretary Problem.

The Secretary Problem

Let’s suppose you want to hire a secretary. You want to find the best person for the job, but you won’t know how good someone is until you interview them. At that point, you can choose to hire them (a permanent decision) or to move on and interview someone else. The only catch is that once you’ve rejected someone, you’re not allowed to go back and hire them.

How do you maximise your chances of finding the right person?

This is a scenario commonly used in optimal stopping theory, a branch of maths involved in finding optimal solutions to these sorts of problems (and many other more complicated ones). The solution is pretty ‘maths-y’, I’ve screenshotted it from Wikipedia below if you can make sense of it (I can’t).

Basically if you knew you were interviewing 100 potential secretaries, you’d interview and reject the first 37, and you’d keep in mind who your best-so-far candidate was as a benchmark. From interview 38 onwards, you’d immediately hire the person better than your best-so-far candidate. This is apparently how you maximise your chances of hiring the best overall candidate.

Why should you care?

Well, because the Secretary Problem is a simple illustration of the explore vs exploit conundrum which shows up in many other areas of life too.

How much should you explore your surrounding areas before deciding on a base to call home? How many internships should you do before deciding on a job offer? How many careers should you try out before you figure out which your favourite is? How many people should you date before deciding to ‘settle down’ and get married?

Obviously, real life is more complicated than a maths problem, but there are a few reasons why I like The Secretary Problem.

1 – It’s quite reassuring to know that there’s a ‘correct’ answer to this issue – ‘explore’ the first 1/3 (ish) of your options, and then choose the best one beyond that point. That means that I probably shouldn’t buy a home in the first city I’ve lived in – I should probably explore a bit more, and then make a decision. But it also means that I shouldn’t keep on sampling forever in the hope that I’ll find ‘the perfect’ city – at some point (sooner rather than later), I should make the decision to settle down.

2 – It’s also reassuring that the mathematically optimal solution only gets the right answer 37% of the time. Even if we boil it down to the simplest form of explore vs exploit, and we use the most optimal formula, we still fail to find ‘perfect’ candidate 63% of the time. This is great. It means that in real life (which is much more complicated), we’re also not very likely to find the ‘perfect’ candidate / person / city / job / whatever, so we can safely give up the expectation that we should. If we find someone or something ‘good enough’ then that’s fine. Perfection doesn’t exist.

I first came across the 37% rule at university when a friend mentioned it in the context of dating and relationships. If we think about the conundrum of finding a spouse mathematically, it sort-of resembles the Secretary Problem – ie: we date people to find out what they’re like, and then at some point we decide to settle down and marry someone who we’re mutually compatible with.

The problem (other than the obvious over-simplification of a complex matter) is that we need to know how many ‘applicants’ we’re dealing with ahead of time, to figure out what 37% of that number is.

If we’ve got 100 applicants for a job, that’s easy enough, but in the world of dating and relationships, how can we possibly know what our total lifetime dating pool’s going to be?

The magical insight that I got from Logan Ury’s book is that we don’t need to think about it in terms of numbers – we can think about it in terms of time.

It’s very hard to know how many people we could end up feasibly dating, but it’s easy enough to estimate how much time we want to spend dating.

If for example, I’m open to dating between age 18-40 (and assuming there’s no radical change in the number of people I’m getting to know each year), the 37% rule says that when I hit the age of 26, I should marry the next best person.

This really struck home for me, because one of my common responses when relatives ask “why aren’t you married yet” is “well, I just haven’t met enough people”. I thought that I needed to date more people to get an idea of what I wanted, and then worry about finding ‘the one’ further down the line.

So I’ll leave you with a question – what ‘explore vs exploit’ conundrum are you currently facing in your life? And do you have any tips or frameworks that you use to help come to a conclusion? Do hit the <reply> button and let me know 🙂

Have a great week!


🎙 I’m starting a podcast!


For the past 4 years that I’ve been creating content on YouTube, I’ve mostly been sharing my own personal experience and curating things I’ve read to (hopefully) help you guys live healthier, happier and more productive lives.

But it’s been a long term dream of mine to have conversations with some of the world’s best entrepreneurs, scientists, creators, authors and other inspiring human beings to find out how they’ve found joy and fulfilment at work and in life. And I want to share these conversations with you.

What can you expect?

In each episode, I’ll be interviewing a new guest about the philosophies, strategies and tools that have helped them along their personal path to living a life of happiness and meaning. We’ll cover a host of topics from eclectic fields like entrepreneurship, psychology, productivity and more.

I’ll be asking my guests questions that will hopefully help you on your own journey, like: “How did you find your purpose?” “How do you set goals?” “What makes a good business idea?” “How can we learn from our failures?” – the list goes on.

I chat more about the podcast in the Welcome video below, but if it sounds interesting I hope you’ll join me for the ride by hitting subscribe to our Deep Dive YouTube Channel or subscribing via your favourite streaming platform so you can stay up-to-date with when we release an episode. Tune in and enjoy the journey!

♥️ My Favourite Things

🎧 Audiobook – I’m re-listening to the Mistborn audiobooks by Brandon Sanderson and they’re even better second time around as I realise all the insane foreshadowing.

🎧 Audiobook – I read Dr Grace Lordons’ book (again on Audible lol) – Think Big. It’s an entertaining listen packed with dense insights from behavioural science about how we can do better in our careers and live.

📚 Book – I read It Doesn’t Have to Be Crazy at Work by David Heinemeier Hansson and Jason Fried of Basecamp. Lots of insights that may change the way I run my business. And their philosophy is definitely aligned with mine on how businesses should work. But, to be honest, I’d recommend it no matter if you’re an entrepreneur or an employee. In both cases it’ll be great read.

✍️ Quote of the Week

“The secret of adventure, then, is not to carefully seek it out but to travel in such a way that it finds you.”

From Vagabonding: An Uncommon Guide to the Art of Long-Term World Travel – Rolf Potts. Resurfaced using Readwise.

🎬 This Week’s Videos

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