the game is totally random, if you save and replay the same game over and over you will get totally different results each time with the same tactic and players.
I remember years ago someone figured out how to rip tactics from AI managers. Some of them were quite good and were subsequently tweaked by the community.
If I was to have a guess it was perhaps around FM12 / FM13?
Does anyone else remember this and is it possible to do the same with FM20?