Two scores are tied together in a knot, and neither side can pull ahead. The contest cannot simply stop there, so one more thing is brought in and the knot is cut. A tiebreaker can be thought of as whatever does the cutting.
可以想成兩邊的分數綁成一個死結，誰也拉不開誰。比賽不能就這樣停在那裡。所以要有一樣東西進來，把這個結一刀切斷。tie 是那個結，breaker 是切開它的東西。tiebreaker 的每一種用法，講的都是「切開這個結的那一下」。
From the word’s history
A compound of tie (a level score) and breaker (the thing that breaks it).
由 tie（平手）加 breaker（打破它的東西）組成，字面就是「把平手打破的那個東西」。
Wiktionary entry for tiebreaker (kaikki extract supplied in evidence packet): "From tie + breaker."
登入就可以看每一支怎麼連回核心畫面。