For every topic there will likely be several answers which can be right. In the case of when do you know you have won/lost, one coach might say, “you win by how you prepare”. Another would tell you that the decision point is right before you shoot the first arrow and that what you have in your mind controls the outcome. I’d say these are all true, but most important: it is decided by the last arrow and you can never know “for sure” until the scoring is done, rather than the shooting. If you decide you’ve lost, you close the door to success and you’ll be on the wrong side. Archery matches are often decided on the last arrow, even when one archer has a superb opening end, provided the other does not give up.
It is important that the coach prepare the athlete to compete by laying a foundation that includes the possibility of not winning as well as winning. In any tournament “there can be only one” who is the ultimate victor and it is important that the expectations be neither too low nor too high.
Time and again, a match is not decided until the last arrow. I would prefer to say that the match is decided by the score of the last arrow. The best archer can still have a miss in the first end, or the last end, and nothing is ever a “for sure” with archery.
Mental lapses happen all the time, and an archer on a seeming perfect path can wander off in a way that allows you to pass and win, provided you did not “quit” before the last arrow of the match.
It is important that the archer be taught to not wander, never to decide a match is over too soon, to remain focused on the things within control, and to not worry about what cannot be controlled. And to never accept a loss or claim a win until the last arrow has been shot.
Success is defined more by how you get to the finish line, not necessarily by the order of arrival.