There is a popular story that is supposed to be historic that depicts battles where one or both sides are completely destroyed. One battle included millions of people and ended with a one on one fight of the last remaining soldiers. I was wondering if anything remotely similar has occurred in history.
Considering the word decimated means one dead in ten, I would guess that 10% casualty rate would be pretty standard for an outright victory
This question goes against the rules of /r/AskHistorians, specifically against "throughout history" questions
One of our key principles regarding questions is that they should be as precise as possible; we do not want threads that will attract only bad answers, or are so generalised that they cannot be answered. We will therefore remove questions that are seeking trivia rather than informed answers.
Also warfare practices throughout the the entire world and all of history have been extremely varied with many different objectives of political, military, and economic nature that have shaped how battles are fought. You should pick a specific region and time period that interests you in order to get a detailed breakdown of the events and influences on battlefield casualties.