Another data point: most successful gamblers seem to treat gambling as a science; bad ones seem to have more OCD rituals to go along with their losing streaks.
Taleb's books seem to make a good case, though, for market success featuring considerable luck.
Also, a variation on this rule of thumb: When other people demonstrate a remarkable skill (dancing, drawing, playing an instrument) it's talent. When you can do it, it's hard work and practice.
Another data point: most successful gamblers seem to treat gambling as a science; bad ones seem to have more OCD rituals to go along with their losing streaks.