influential person; powerful person; big wheel; big gun; power behind the throne
merit system (as opposed to seniority); meritocracy; ability-ism
talented person; person known for real ability rather than looks
beyond oneself; beyond one's ability; exceeding one's power
according to (depending on) one's ability; if one is good (competent, talented) enough
(the two persons' sides) being evenly matched in ability
the precedence of merit; performance orientation; ability-based (promotion, pay scale, etc.); merit-based