烧冷灶

Traditional (Taiwan): 燒冷灶

shāolěngzào ㄕㄠ ㄌㄥˇ ㄗㄠˋ

    • to befriend or favour someone powerless who may be useful later
    • to back an underdog

Character by character

Saying俗语俗語

Idiom惯用语 · Widely known

Literally
light a cold stove
Meaning
To make friends with or favour someone who has no power yet but may be useful later, like betting on an underdog. Often seen as shrewd, set against the usual 'kowtowing to the powerful'.

Sources