“Ow me! as Lysander once said to Hermia. “For all I could ever read, Could ever hear by tale or story, The course of true love never ran smoothly.” To put it more succinctly: love stinks. But it doesn’t have to be! Despite their unduly asexual reputation, mathematicians have had a way of finding The One for decades – it’s called optimal stopping theory.
“[Optimal stopping theory] literally amazes me,” mathematician Hannah Fry wrote in her 2015 book The Mathematics of Love: Patterns, Proofs, and the Search for the Ultimate Equation.
“If you chose not to follow this strategy and instead chose to settle down with a random partner, you would only have a 1 in 2 chance of finding your true love, or only 5% if you are destined to date. with 20 people in your life, for example,” she explained. “But…by following this strategy, you can dramatically change your fortunes, up to 38.42% for a fate with 20 potential lovers.”
What is this magic formula? Well, it looks like this:
Don’t worry, we’ll explain it to you in a minute. Image credit: Hannah Fry via Ted.com
But unless you have a degree in advanced mathematical matchmaking, that probably doesn’t mean much on its own. Let’s break it down a bit more – and see if we can take some dating tips out of the equation along the way.
The good news is that it turns out that the mathematically optimal dating game is the one you’ve probably played before. The best tactic, according to this formula, is to date for a little while – and once you have a little experience of who’s there, then settle with the first person you meet better than anyone. who came before.
And it is the duration of this “little time” that the formula tells us. So, first of all, we better explain the terms. We have P(r) on the left, i.e. the probability of finding the best suitor as a function of r- the number of potential Ones you reject – and not- the total number of possible Mr, Ms or Mx rights you have globally.
So, let’s say you’re destined to meet 10 potential romantic partners throughout your life. Then your probability of finding The One depends on how long you wait like this:

As you get harder, your chances of finding love increase. Until a certain point. Image credit: (C) IFLScience
By following the strategy, your odds top out at just under 40%, which you can reach by rejecting the first four people you date. And sure, a two in five chance of finding true love doesn’t sound like much, but it’s a whole lot better than picking a life partner at random – that would translate to only a one in 10 chance of you ending up with the right person.
And the more people you’re destined to date, the better the Optimal Quitting Theory can improve your odds. For 25 potential mates, your odds look like this:

You can start to see a pattern, right? Image credit: (C) IFLScience
This time, your chances of finding the best partner are higher if you reject the first nine potential partners, giving you a 38.1% chance of finding true love. In comparison, picking randomly would only give you a 4% chance.
And if you don’t feel like limiting yourself to a finite number of potential partners – of course there are only 8 billion people on Earth, but if we have to invade Alpha Centauri to find a date then so be it – then we find the ultimate threshold: 37%.
Now, there are a few flaws with this strategy: “Imagine that during your 37% rejection phase, you start dating someone who is your ideal partner in every possible way,” Fry points out. “Having not met everyone yet, you would have no way of knowing they were the best on your list and you would let them go.”
“Unfortunately, once you started looking more seriously for a life partner, no one better would ever come. By the rules, you should continue to reject everyone for the rest of your life, grow old and die alone,” she wrote.
And the reverse situation is just as bad: if everyone you reject is terrible and rude, then “the first person you meet better than anyone before you” might just be the first person you meet, period. This person might only be a tiny bit better than previous matches – but nonetheless, the strategy would require you to settle down with them in a lifelong partnership that’s barely better than horrible.
Then there’s the sheer logistics of it all – after all, who knows in advance how many people will they date in life? But here, at least, the 37% rule has an advantage – as it turns out it can be used in a whole host of different situations.
Thus, Fry pointed out, the problem can be adapted to consider time, rather than individuals: “Let’s say you start dating when you’re 15 and ideally you’d like to settle down by age 40,” she explained. “In the first 37 percent of your dating window (until just after your 24th birthday), you should reject everyone… After the rejection phase passes, choose the next person who comes in and who is better than anyone you’ve met before.”
“Following this strategy will definitely give you the best chance of finding the number one partner on your imaginary list,” she added.
And that doesn’t even have to apply to romance. “You have three months to find accommodation? Reject everything in the first month, then choose the next house that comes along that is your favorite so far,” Fry wrote. “Hire an assistant? Reject the first 37 percent of applicants and then give the job to the next one you prefer above all others.
So there you have it: the key to a successful love life — and perhaps also to successful house-buying and house-hiring strategies — was in math this whole time. It just goes to show what we’ve known all along: math really is the sexiest of all sciences. Take that, sexology.