Chris Evert got very, very far in terms of excellence and durability on the pro tour. I'm not sure how much some 'luck' had to do with it. Afterall, who gets to define what luck is? Do the players get to choose their own luck? As far as Evert's athletic talent., I'd say she had more than a bit of innate athletic talent. IMHO, her athletic talents were supreme and underappreciated. I think most would agree - and Evert would be the first to say so - she didn't look a typical "jock." But did you ever see Chris get tired in a match? Winded and out of breath? How often did she retire mid-match or mid-tournament because she pulled up lame? Was she constantly overusing certain muscles or overcompensating with her strokes? Did she have a glaring weakness in a stroke, such as serve, volley, overhead, FH, BH, drop shot, lob? How often was Chris really late to the ball? Or appear terribly out of shape or slow? Would she flail at balls, attempt power shots without any power? Did you ever see Chris Evert play tennis looking uncoordinated in any way?
That's the thing. Chris athletic talents were so pure, so finely tuned, so immaculately executed that fooled you into believing she didn't have them. Pair her athletic gifts with her iron clad mental fortitude, self-belief and self-confidence, determination, [plus discipline, tenacity, and ambition] and hatred for losing and you have the right combination for achieving the highest degree of success in the history of professional tennis (Chris won 90% of her matches in her career - which is more than 1300 wins in a 19 year career!, second to none).