True Strength
True Ability, True Power
noun
The truth behind someone's strength is their true strength. It is also their true ability.
じつりょく
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
コウイチのフラダンスの実力は本物です。
Koichi's hula dancing abilities are genuine.
ビエトが本気の実力を出した所を見た人はまだだれもいません。
There is no one who has witnessed Viet's true power yet.
運も実力のうちってよく言うだろ。
They usually say, "luck is what you make of it."