1 min read

If you flip a coin, the probability that it lands on heads is 50%.

So if you flip a coin 10 times, how many times would you expect it to land on heads?

We can use a simple formula to answer this:

Expected number of heads = **(probability of landing on heads)** * **(number of flips)**

In this case, expected number of heads = **(0.5)** * **(10)** = **5**

If you actually flip a coin 10 times, though, it won’t always land on heads exactly five times. Sometimes it will only land on heads four times. Or six times. Or in rare cases, zero times.

The *expected* number of heads and the *actual *number of heads are not always equal, but we know that the actual number of heads will likely increase with more flips.

I like to think that there exists a similar formula for success in life:

Expected number of successes = **(probability of success)** * **(number of attempts)**

The “probability of success” is the sum of your skills, experience, and knowledge. The more you have, the higher your probability of success. And the “number of attempts” is purely how many times you try something.

When I applied for data scientist jobs last year, I only had one year of experience, mediocre skills, and not a ton of knowledge in the field. My probability of getting hired by any given company was maybe 10%. Fortunately, I decided to apply to 10 different companies. This meant my expected number of successes was:

Expected number of successes = **(0.1)** * **(10) **= **1**

And I did get an offer from exactly one company, which I accepted.

I’m using these numbers and equations to make a simple point: to succeed in any area, you need to build up your probability of success *and *you need to commit to making several attempts at something.

Someone who has an incredible set of skills, experience, and knowledge won’t find success if they never make any attempts. Likewise, someone who completely lacks skills won’t find success purely through making dozens of attempts.

The trick is to combine the two. Increase both your skills and your number of attempts to increase your expected number of successes.

My favorite free financial tool I’ve been using since 2015 to manage my net worth is **Personal Capital**. Each month I use their free Investment Checkup tool and Retirement Planner to track my investments and ensure that I’m on the fast track to financial freedom.

Sign up to have my most recent articles sent straight to your email inbox for free ?

Full Disclosure: Nothing on this site should ever be considered to be advice, research or an invitation to buy or sell any securities, please see my Terms & Conditions page for a full disclaimer.

Ahh, this is a great analogy. Probability 101.

Expected number of successes = [(probability of success) * (number of attempts)] * Randomness/Luck.

Would be how I see , at least if the LHS is about a BIG success. The base equation still holds true though !!

Cheers.

I left randomness/luck out of the equation because it’s something that is out of your control. It certainly plays a role, though. Thanks for the feedback, Rahul!

Great point Zach. The problem I always struggle with is trying to get my skills up to “par” before I make any attempts. In reality though, I need to be making attempts along the way of skill improvement. One, it will give me feedback. Two, it will prevent me from waiting until my skills are “perfect” and still not making attempts.

Thanks for the short but powerful reminder.

You nailed it – the more attempts you make, the more feedback you’ll receive and the more you’ll improve. Perfectionism is the enemy of progress!