厚hòu积jī薄bó发fā

Literal: store up thickly, release thinly
Figurative: To build up knowledge and experience patiently for years before showing it; unlike 一鸣惊人, which stresses the surprise, the weight is on the long groundwork.

Where does 厚积薄发 come from?

It comes from 《稼说送张琥》, a piece the Song-dynasty writer Su Shi wrote as a farewell to his friend Zhang Hu. In it he compares study with farming: the rich reap good harvests because they can let the land rest and wait for the grain to ripen. He closes with a piece of advice: read widely and take sparingly, store up much and give out little. In the original, 薄发 was a call for restraint, for showing only part of what one knows. Today it is mostly understood as preparing for a long time and then making a brilliant leap.

Source (出处): 苏轼《稼说送张琥》

How is 厚积薄发 used? Two examples

她tā练liàn了le十shí年nián钢gāng琴qín，从cóng没méi参cān加jiā过guò比bǐ赛sài，今jīn年nián一yī出chū手shǒu就jiù拿ná了le冠guàn军jūn，真zhēn是shì厚hòu积jī薄bó发fā。
She practiced piano for ten years without entering a single competition, and this year she took first prize on her first try: years of quiet work finally paying off.
老lǎo师shī傅fu在zài别bié人rén的de后hòu厨chú干gàn了le二èr十shí年nián，一yī开kāi自zì己jǐ的de店diàn就jiù火huǒ了le，靠kào的de是shì厚hòu积jī薄bó发fā。
The veteran chef spent twenty years in other people's kitchens, and the moment he opened his own place it took off, built on everything he had quietly stored up.

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