If you play a match TIE with enthusiasm at 5, it´ll be 6,6 after the match and you´ll play the next match with enthusiasm at (6)6,33. Playing again TIE it´ll reach 8,42 and you´ll play the next game with enthusiasm at 8(7,79) and so on. I usually play TIE and it reachs a point that playing TIE with high enthusiasm is like playing Normal at 5 and better.
Best regards.