Who is Dad from Crank and what is their importance?

It is important to notice that nowhere in this story is Kristina's father given a name. He is always refered to as "Daddy" or "Dad." This may indicate that the only importance he had in Kristina's life was his ability to be her biological father and give her life. He never develops into a father whom Kristina can relate to as a person or a role model. In fact, Kristina's father, if anything, encourages her to pick up bad habits by ignoring her and treating her as if she is not important. Kristina's father works at a bowling alley where he is paid in cash. Most of his money goes to support his drug habit. Kristina witnesses him high on both crank and marijuana. It is during this time with little or no parental supervision that Kristina gets involved with Adam and with crank.