One of the most important things I learned at Tech was in decision tree analysis. You can make a good decision and have a poor outcome. (Call it chance, luck, chaos, whatever.) You can make bad decisions and have good outcomes. The key is making good decisions give you higher probabilities of good outcomes over time. And when you have bad outcomes, the cost is minimized.
You might buy a lottery ticket and win the jackpot, doesn't mean buying lottery tickets is a smart financial decision. MoBS made terrible decisions, consistently. Still, he got some breaks to win games like UNC at MBS. Saban has had lots of 'lucky' breaks in games that saved championship seasons. But he was only in the position to benefit because his team was prepared to take advantage.
Good coaches consistently make good decisions, have good game plans, do the right things. Even so, sometimes, the ball bounces wrong and the refs are struck blind (bad luck). Key, I believe, consistently makes the right calls. So, when opportunity knocks, his team is positioned to take advantage of those 'lucky' breaks. When we have bad breaks, hopefully, we're positioned to minimize the damage.