In team sport, the first-string players are the ones the coach sends out at the start of the game because they are the best. The rest wait on the bench and come on later, or not at all — they are second-string. So 'the first-string quarterback' is the main quarterback, the one you would name if someone asked who plays that position.

In team sport在團隊運動裡, the first-string players are the ones the coach sends out at the start of the gamefirst-string球員是教練在比賽一開始就派上場的人 because they are the best因為他們是最好的。The rest wait on the bench其餘的人坐板凳 and come on later, or not at all之後才上場，或根本沒機會上場 — they are second-string他們就是second-string。So 'the first-string quarterback' is the main quarterback所以「the first-string quarterback」指的就是主力四分衛, the one you would name if someone asked who plays that position也就是如果有人問誰打這個位置，你會第一個講出來的人。

This is American English, and it sits most naturally in American sports talk: football, basketball, baseball. British speakers would say 'the first team' or 'the starting eleven' for football. In American sport you will also hear 'the starters' or 'the starting lineup', and honestly those are more common in everyday speech now; 'first-string' has a slightly coach-ish, school-team flavour.

This is American English這是美式英語, and it sits most naturally in American sports talk最自然出現在美國的運動用語裡: football, basketball, baseball美式足球、籃球、棒球。British speakers would say 'the first team' or 'the starting eleven' for football英式英語講足球時會說「the first team」或「the starting eleven」。In American sport在美式運動裡, you will also hear 'the starters' or 'the starting lineup'你也會聽到「the starters」或「the starting lineup」, and honestly those are more common in everyday speech now老實說這兩個現在日常口語更常用; 'first-string' has a slightly coach-ish, school-team flavour而「first-string」帶點教練或校隊的味道。

The word travels outside sport too. 'Our first-string lawyers' means the top people, the ones you bring when it really matters. And 'second-string' has drifted furthest of all — calling a person second-string is a mild put-down anywhere, meaning not quite good enough for the main job.

The word travels outside sport too這個字也用到運動以外的地方。'Our first-string lawyers'我們的一軍律師 means the top people指的是最頂尖的人, the ones you bring when it really matters也就是事情真的重要時你會找的人。And 'second-string' has drifted furthest of all而'second-string'這個字變化最大, calling a person second-string is a mild put-down anywhere不管在哪裡，說一個人是second-string都是種輕微的貶低, meaning not quite good enough for the main job意思是還不夠格擔任主要工作。

Where does 'string' come from? A string here is a line or set of players grouped by ability — first string, second string, third string. Coaches literally list them in strings. It is the same everyday word as a string of beads: things lined up in order.

Where does 'string' come from?'string'這個字是怎麼來的？A string here is a line or set of players grouped by ability這裡的string是指依能力分組排列的一列球員 — first string, second string, third string第一線、第二線、第三線。Coaches literally list them in strings教練真的會用「strings」把他們列成一組一組。It is the same everyday word as a string of beads這跟a string of beads（一串珠子）的string是同一個日常用字: things lined up in order指東西按順序排成一列。