One major frustration facing new entrepreneurs and managers, particularly in sales, is why a particular process that works most of the time does not work every time.

When it comes to predicting the weather (70% chance of rain today), illness (15% chance of getting the flu), or business success (50% of new businesses fail), our lives seem ruled by statistics. But statistics are only relevant after you have tried a process a significant number of times, what mathematicians call having enough “frequency.”

You may have a sales process that succeeds with more than 50% of your qualified prospects, yet a new salesperson may fail again and again only to give up in frustration. Here’s an exercise I use to teach frequency to new employees and students.

I ask the person to flip a coin 10 times and record the result. Most people think it’s going to be an even 5-5 split between heads and tails. It’s not—it’s often 7, 8, or even 9 heads. Then I ask them to continue flipping the coin 90 more times (100 total)—and it’s almost always 51 to 49 heads or tails. This is a great exercise to teach that you need to try something more than 10 times to figure out if it works.

This exercise also teaches why you must have enough frequency before scaling your business. You might develop a strategy that fails with the first 8 or 9 of your 10 initial qualified prospects, but then succeeds with 50 percent overall. Conversely, you might experience success on the first few sales calls and then expand too fast with a non-sustainable model.

As a teacher and as a parent, I am often asked by young people “how come” a particular effort didn’t lead to the expected reward. While I’ve tried to console my students, I, too, have been frustrated that although God made a world with rules and order, God also made a world in which those rules don’t generally work until you have enough frequency.

Some people think God did this because He didn’t want people to become too cocky by having things work out for them every time.

Some people think God did this because He wanted to give a chance to those who didn’t have all the qualifications that others dictated they needed to succeed.

And some people think that God did this because He wanted a world that would constantly challenge, and thus strengthen, our faith. A world where everything doesn’t work outevery time, but a world where everything does work out over time—especially for those of us, like Job in the Bible, with enough faith to follow our plan regardless of how much adversity we experience.

What do you think? Why did God create a world where every thing doesn’t work everytime?