This is complete competence. It is different than ability. Ability is something you are blessed with. Becoming skilled at a trade, a sport or a position is something that takes time, practice, repetitious practice.
Being skilled means constantly searching for knowledge and information that will improve your abilities and make you more competent.
The concept of “mastery” is the never ending quest to continually improve your skill level.
Being skilled means “knowing” what your doing and being able to do it.
It is not always the guy with the most ability that succeeds, many times it is the person who applies himself and becomes complete. This is especially true in baseball.