A ball can live 20+ years. I really think it depends on that snake, it's background/history, and it's owners husbandry efforts. I know Pete's original Pied is at least 20 years old, maybe a bit older since Pete guess he was about 10 when he got him. That snakes really looks like a wise old man.

On the other hand some snakes die young for no reason at all. They are fine and bam one day you just find one dead. Some are older then others, some extremely young. I do believe it really does play in to the bloodlines and how the snake is kept. Just my 2cents.