What Do You See in a Person That's Not Good at Managing Variability?

Avanica Tannegan was close to winning the A&A, the first major of the year in 2016. But she ignored it because as we talked, she was aware of that she was leading. She learned when she feels like, okay, I'm close to winning. I'm thinking more, which is really normal. So what would be the traits of someone who is not very good at managing variability?