Not to be an ass, here, but there is no such thing as chance. Nevertheless, your reasoning is human, not Scriptural. God doesn't claim to be fair, but just. Fairness and mercy are not at all the same thing.
He is perfectly just to do whatever he chooses with his creation, making humans responsible for their own sinfulness, inherited from Adam even, planned by God to come to pass. But he is merciful to some, not putting their sins aside unpaid for, but by substitution of his Son in their place.
A certain farmer realized that he didn't hire enough men to clear his field before the day was out, so he went and hired some more, agreeing to pay them for the part-day the same amount as those he had hired for the full day. Later that day he again went and hired men under the same agreement. So why should those who hired on for the full day complain. They received what they had agreed on. --- So it is with the condemned. What those upon whom God shows mercy receive is no business of those whom God condemns. In fact, if it IS their business, then all the more condemnation on them for rejecting his gospel of salvation, and instead demanding more than they deserve.