You can't play TIE in scrimmages at all.
Playing TIE in league games and cup games will raise enthusiasm by 33%.
Playing CT in league games and cup games will lower enthusiasm by 50%.
Playing Normal will not affect enthusiasm, but every day the enthusiasm will naturally move back towards 5.
The further away the enthusiasm is from 5 the bigger the leap back to 5 will be each day.
During playoffs this all changes.