You can use win bonus in a season and have worst results from previous season.
You can play in every game with your players having "yellow" condition and play better
You can use or not, the training bonus, to watch or not your games, to use the same formation or trying to find the right counter.
All those are just some of the factors with a small or little bigger part in the game.
One season I was tanking, I used my GK as ST and the opposite and won 20% of my games.
You can't have any conclusion from only one factor.