Again, I'm taking a break of talking about cards. This time we're going to talk about a thing far more decisive than cards in the game: the player.
In a way, in a duel between 2 decks of equal potential, if a player does every move exactly as it supposed to be,no misplays and no bad choices and he/she still loses, there's only luck to blame. If there is at least one misplay, the player has the total right to blame himself/herself (although he/she shouldn't take it too seriously, it's a game, after all). If both players do misplays, the overcome of the duel is just chaotic, so it would be best if in these games there was a judge or a spectator with enough knowledge to point out the misplays.
But, in a tournament, no matter what level it is, there are some other conceptions that makes the game different than casual one. We can see this while playing some decks:

