In his article Absolute Success is Luck. Relative Success is Hard Work., James Clear provides a pair of stories about how luck (including the circumstances one is born into) and hard work both play a role in success. He concludes that luck controls absolute success and hard work controls relative success.
Later in the article, he has an engineeering/science way of conveying his idea:
Imagine you can map success on a graph. Success is measured on the Y-axis. Time is measured on the X-axis. And when you are born, the ball you pluck out of Buffett’s Ovarian Lottery determines the y-intercept. Those who are born lucky start higher on the graph. Those who are born into tougher circumstances start lower.
Here’s the key: You can only control the slope of your success, not your initial position.
There are more gems as well as several good stories in the article and I highly recommend you read it.
He closes noting that one can not control luck but can control the hard work input. I would qualify this to note that it has to be correctly focused hard work.