功力 (gōng lì): merit; efficacy; competence; skill; power

His calligraphy skill is profound; every stroke appears vigorous and powerful.

After years of practice, this martial arts master's skill has reached a state of perfection.

To play this role well, an actor needs deep acting skills.

Because he has practiced piano for a long time, his performance skill is very solid.

This painting displays the painter's extraordinary skill, leaving people full of admiration.