knowing one's stuff

accomplished capable competent mature professional qualified seasoned skillful sophisticated trained veteran wise

accustomed cultivated dynamite instructed matured practiced rounded sport tested tried versed vet

adept been around been there broken in expert familiar having something on the ball in the know knowing the score old old hand practical pro the right stuff well-versed worldly worldly-wise

amateur green ignorant incapable incompetent inept inexperienced unable unskilled unskillful untalented untrained

immature unfamiliar unknowledgeable unseasoned unsophisticated

competent efficient experienced licensed qualified skillful

ace adept crackerjack expert sharp slick there

able acknowledged big-league finished known learned on the ball polished practiced proficient up to speed well-qualified

green ignorant incapable incompetent inefficient inexperienced unable unskilled untalented

clumsy inept stupid unintelligent

amateur rookie unprofessional untrained