i hesitate to say this as a big venus fan, and it's probably simplifying, but given they both have power and physical gifts (not identical gifts obvs) i think serena demonstrates how far you can take that if you are technically sound, smart and willing to alter stroke production to become as effective as possible
i'm not sure venus has done the same and their careers have diverged hugely in the last 4 years
amazing to think that going into their 08 us open qtr venus was on 7 slams to serena's 8, and prob would have equalled serena had she taken that match, instead serena has surged ahead in the stats
I don't want to make this a Serena-Venus thread.
I am also primarily a Venus fan, and I think her biggest problem is her stubbornness.
Serena is not shy or afraid at seeking input outside of her inner circle.
I have no solid evidence, but just by observation, I think she is more willing and eager to develop specific aspects of her game than Venus.
Serena has hired people to work on specific area of her development.
For example, before coming back form her illness, she hired a fitness coach just to get her endurance and muscle strength to an adequate level.
Right now, she has been working with a French consultant she hire around FO, I heard his role is more psychological than technical or physical.
All these things keep Serena ahead of the game.