It's also important to understand that in a best of 3 format, if you have a 80% winrate per game against every player (which is insane btw), you still lose 10% of those matches. In a 9 round tournament day (which is standard for YuGiOh iirc), your chance of winning every single round for the entire day is merely 40%. If your edge is more realistic, say 60% winrate, then you lose 35% of those matches. More games per match are your friend for determining who is actually better.