Re: Do you believe in luck in tennis?
A formerly considerable junior tennis player and old friend of mine once told me "There's no such thing as luck in tennis, only percentages." Since then, I've always thought back to that adage as it relates to this sport.
Luck is what we ascribe to certain miniscule and sometimes "uncontrollable" factors that might contribute to a given outcome. If we look close enough, everything has causation that might otherwise be perceived as "luck". The concept is universal, meaning it applies to everyone, and in some sense, it could be a factor of every thing (that happens in tennis, at least) as well. Because of its broad application, I tend to think it's negligible.
In the end, players usually have the greatest say in what happens, be it in a match or their career.