Luck

I've had occasion to win a couple of games against 1400-1500 ranked players (and me strictly 1250-ish material), and while in my own personal shorthand I described both of those games as "@#$%, I sure lucked into that one," the reality of the situation was that each of my opponents made a critical error that I happened to catch in time to do something nasty to exploit it.

Game 5366472

There are ocassions when'incorrect moves' are deliberately selected for play normally at knowledgable levels and above,that is to say moves which are known not to be generally considered the very best of choices in a particular position.There are several possible reasons for such moves particularily those possible moves which may be only slightly inferior to some alternatives. Tactical and or advanced positional reasons are usually the main considerations when deliberately selecting slightly inferior moves,which does not always have a negative effect on the result of a game play,for one or the other side.Selecting'only' the very best possible move/s is not in reality a necessity for the successful completion of a game at specific stages of the game ,especially if a drawn game is the desired or acceptable result,as is often the case in higher and lower levels of chess theory knowledge. Fortunately for higher rated players,lower rated players are often unable to clearly see the difference between what may indeed be the best opponent move/s ,and what is very nearly but not quite as good a move.A more advanced and or experienced opponent player may well be able to do so,making such slightly inferior moves a somewhat risky proposition,but quite often worth consideration.😉

Its easy to know if your making a mistake or not. Those moves we take 20 minutes on and still don't have a clue which one is best. We often make those mistakes and we know that they are subject to be scrutinized by your opponent and you wont even know how bad or good it was until after the game.