Actually, Wyatt Earp talked about this issue in his autobiography. He attributed his success in gun fighting to always talking the time to aim. He fought people who out drew him but fired from the hip, or just drew and shot or people who would pull and fan. He shot slower, but hit what he aimed at and generally scoffed at people who used the pray and spray method of gunplay.
He also practiced with the guns he was most comfortable with. In addition, he was pretty smart. When he faced multiple opponents, he brought friends and tried to pick his ground carefully. I'm not saying luck didn't play a part, but he did his best to reduce the part it played as much as he could.