Favourites for matches

Can anyone tell me how its calculated for whose the favourites to win matches? I'm currently Leicester and so far I've played Man Utd, Tottenham and Chelsea and my assistants advice before the game is to tell my players were favourites to win.

Is this a bug? or is my assistant not very good lol?

I think a lot of it is down to league position, plus as Leicester are the current champions in FM17 (i think) that may have an impact too. Even so it usually makes no sense to me either.