The
Pareto principle, 80/20 rule. The top twenty percent. no matter how they
get there through a combination of talent, coaching, and financial
support will likely garner eighty percent of the revenue/resources.
To achieve your highest level of play you can balance where you spend the resources or bootstrap your way into the to twenty percent with sweat equity meaning discipline and practice. Beyond that, to keep things going you need to acquire as many resources to support a sustained effort to remaining at the top.
New WTA now allows coaching from the stands - is it fair?