I always used to have the tackling <<normal>>, but because I took some yellow cards I turned it into <<easy>> in order not to take any other cards and then BOOOOOM 1 red card 3-4 yellow cards in a single game...
Then I turned the tackling into <<hard>> and for 2-3 games I didn't take any cards at all. I haven't changed it since then. Was it just a coincidence ? Or is it a bug ?