When Should You Stop Searching for the “Right” Candidate?

In my experience of 7 years in Human Resources, if there’s anything that is as complex as landing a man on the moon – its finding the right candidate. We’ve all been there—endlessly scrolling through resumes or sitting through countless interviews, waiting for that elusive “perfect candidate” to walk through the door. And as if the challenge of interviewing numerous candidates isn’t enough, we struggle to resist the urge to keep searching for someone better, hesitating to hit pause and make the final decision because we are uncertain about the quality of the yet unseen applicants

While Human Resources is all about dealing with Humans and their emotions, it's beautiful to see how Math plays a role in answering the above. In this article, we’ll explore:?

An approach (popularly known as the Secretary Problem) in decision-making called “optimal stopping” that can be used for all life’s problematic decisions whether that's choosing a career, buying a house, or even deciding who we want to spend the rest of our lives with.? ?

The Optimal Stopping Rule?

The optimal stopping rule for this problem is surprisingly elegant and revolves around a simple principle:?

Observe but do not select the first 'X' candidates.?

After the first 'X' candidates, select the next candidate who is better than all the previous candidates.?

The Scenario

Here’s where it gets interesting. Let’s say you plan to interview a set number of candidates.

You have a limited amount of time to interview each one, and once you’ve completed an interview, you must decide whether to hire or move on to the next candidate. Once a decision is made, you cannot reconsider it. The goal is to hire the best candidate possible. However, at a certain point in the process, you won’t know if a candidate is the best because you haven’t seen all of them yet!

There are two ways to fail: You might stop too early, or you might stop too late

A common strategy is Look-then-Leap: for a fixed number of candidates, you look but don’t hire. After gathering information, you hire the first candidate who is better than the ones you've seen.

For example, if you interview 3 candidates, you’re not going to hire anyone yet.?After that initial phase, you set a benchmark based on the candidates you’ve seen. If the next candidate you interview surpasses that benchmark, you hire them right away. This way, you’re not stuck in endless indecision.?

Between leaping for the best amongst 3 candidates, we have 3 scenarios to consider:?

Scenario 1

We directly hire (so there is no looking period). We only interview the starting candidate and hire directly. We have 33.3% chance to hire the best candidate (number 1), but also 33.3% chance to hire one of the other candidates (number 2 or 3):?

Scenario 2

Our second option is to don’t hire the first candidate we interview (look), and then hire the second candidate if this candidate is better than the first. If the second candidate isn’t better, we automatically end up with the last candidate.

Scenario 3

The final scenario is that we don’t hire the first two candidates, this means that we always end up with the last candidate. That is as good as scenario one, because in this case we end up with the best candidate in 1 out of 3 cases. But wait…We spend more time interviewing during this scenario! That’s true, and that’s why most people would prefer scenario 1 compared to scenario 3.??

For 3 candidates, the optimal stopping point is after the first interview (scenario 2).??

What happens if we increase the pool of candidates? Luckily, the math folks have given us an entire list of probability percentages based on the pool boiling it all eventually to a magic number 37. For any pool >= 100, when you have a time limit, spend 37% of the total time looking and then settle for the next best candidate.? ?

How does it all work in real life??

Like many mathematical models, applying the 37% rule to real life can be challenging. In reality, things aren’t as straightforward, and there's also the cost of searching to consider.?

In the interview scenario, we assume you know nothing about the candidates before meeting them. But in practice, that’s unlikely — you typically have resumes, LinkedIn profiles, or even case studies or questionnaires, allowing you to start comparing candidates before the interview.?These elements allow you to form preliminary assessments and set benchmarks for comparison. As a result, your "look" phase is somewhat front-loaded.

Getting Out of the Perfection Trap?

Also let’s be real—there’s no such thing as the perfect candidate. Instead of searching endlessly for a candidate who ticks every single box

Identify that "Good Enough" often leads to great hires who fit and grow within the team.??

This mindset shift can revolutionize your hiring process, allowing you to prioritize skills, culture fit, and adaptability over unattainable perfection.?

Wrapping It All Up?

The beauty of optimal stopping is that it frees you from the stress of overthinking. It gives you a clear framework for making timely, effective decisions without losing sight of what matters most. Instead of spending months in the hiring process, you can confidently make decisions, knowing you’ve done your due diligence.?

So next time you’re in the middle of interviews, take a step back. Ask yourself: “Have I gathered enough information? Is it time to stop searching?” The right candidate may be closer than you think—if you just know when to stop looking.?