万无一失

1. Basic Information

• Pinyin: wàn wú yī shī
• English Translation: Not a single failure in ten thousand (foolproof/fail-safe)
• Idiom Composition: 「万」（Ten thousand; representing all possible cases or attempts）＋「无」（Without; none）＋「一」（A single (instance of)）＋「失」（Failure; mistake; loss）
• Meaning: To be absolutely certain of success; a state where there is no possibility of failure because every risk has been eliminated through meticulous preparation.

2. Detailed Meaning and Nuances

「万无一失」 contains the following nuances:

• Absolute Certainty: This idiom does not just mean a high probability of success; it emphasizes a level of certainty where mistakes are theoretically and practically impossible.
• Meticulous Preparation: It implies that the guaranteed result is the direct consequence of exhaustive preparation and the elimination of all potential loopholes.

3. Usage

「万无一失」 is mainly used in the following contexts:

• Planning and Business Projects: Used when reporting or confirming that all risk countermeasures have been taken before a critical project or event.
  • Example:「为了确保这次发射任务万无一失，工程师们进行了无数次测试。」
    （To ensure this launch mission was foolproof, the engineers conducted countless tests.）
• Safety and Security: Describes a security system or safety management protocol that has no loopholes or vulnerabilities.
  • Example:「警方的安保措施做得非常严密，可以说是万无一失。」
    （The police security measures were extremely tight; one could say they were fail-safe.）
• Expressing Absolute Confidence: Used to reassure others that a plan or one's own ability is beyond doubt.
  • Example:「你放心吧，这个计划我已经反复推敲过，绝对万无一失。」
    （Don't worry, I have refined this plan repeatedly; it is absolutely certain to succeed.）

Additional Examples:

1. 要想做到万无一失，我们必须考虑到每一个细节。
   （To ensure everything is foolproof, we must consider every single detail.）
2. 虽然很难保证万无一失，但我们会尽最大努力降低风险。
   （Although it is difficult to guarantee absolute certainty, we will do our best to minimize risks.）
3. 这种手术风险很高，医生也不敢保证万无一失。
   （This surgery is high-risk, and even the doctor cannot guarantee it will be completely without risk.）
4. 只要按照说明书操作，就能万无一失。
   （As long as you operate according to the manual, it will be fail-safe.）

4. Cultural Background and Notes

• Origin: This expression evolved from the phrase 万不失一 (wàn bù shī yī), which appears in the Records of the Grand Historian (史记), specifically in the 'Biography of the Marquis of Huaiyin' (淮阴侯列传). Since ancient times, it has been a vital term for promising total victory in military and political strategies.
• Modern Usage: In modern Chinese professional life, the phrase 确保万无一失 (què bǎo wàn wú yī shī), meaning 'to ensure nothing goes wrong,' is frequently used as a slogan in sectors like aerospace, finance, and public safety where the cost of failure is extremely high.

5. Similar and Opposite Idioms

• Similar Idioms:
  • 十拿九稳 (shí ná jiǔ wěn): Literally 'nine out of ten,' meaning very likely to succeed, though it carries a slightly lower degree of certainty than 万无一失 (wàn wú yī shī).
  • 稳操胜券 (wěn cāo shèng quàn): To have the victory in one's grasp; to be assured of success.
  • 板上钉钉 (bǎn shàng dìng dīng): Something is settled and cannot be changed.link
  • 胸有成竹 (xiōng yǒu chéng zhú): To be confident and have a well-thought-out plan before taking action.link
• Opposite Idioms:
  • 百密一疏 (bǎi mì yī shū): A single slip in a hundred points of care; a small oversight in an otherwise meticulous plan.
  • 漏洞百出 (lòu dòng bǎi chū): Riddled with holes; full of flaws, errors, or omissions.
  • 危机四伏 (wēi jī sì fú): Dangers lurk on all sides.link
  • 险象环生 (xiǎn xiàng huán shēng): To be surrounded by dangers; to be in a perilous situation.link

6. Summary

The idiom 万无一失 (wàn wú yī shī) literally means 'not one failure in ten thousand.' It is used to describe plans, security measures, or projects that are so perfectly prepared that they are considered completely foolproof. Beyond just expressing confidence, it emphasizes the objective perfection of the arrangements made to ensure a successful outcome.