Dude, listen-
ENTHUSIASM IS HUGE!!!! in this game.
I found out the hard way as well. I've taken some tough losses and really had some funky game outcomes. I was RATED WAAAY better and lost the other day. I really felt that somebody running the game is deliberately tilting the game against me (since I've been critical of this game on the forums I thought maybe a programmer took it personal and was out for me).
BUT I think its just enthusiasm.
ENTHUSIASM ENTHUSIASM.
It seems to have MORE of an impact on your performance than- Gameshape,Stamina&effort COMBINED.
Seriously. I've not been playing that long, but the games I've lost, especially the ones I lost to crap teams was when I had low enthusiasm.
I've gotten away with not so hot gameshape, attrocious stamina and even Take it easy at times. but Enthusiasm of 3 or lower and..... Yea.
PERHAPS enthusiasm is overated in this games, but its an interesting Xfactor, something that makes upsets possible, which makes the game more real I suppose.
Like if there were no Effort or enthusiasm ratings than everything would come down to base stats and game shape. That would probably make the game WAAAy easier to predict. and maybe they figure that would make it less exciting.
ONE THING- I think Stamina should play a bigger role. I don't think it should necessarily play into injuries or gameshape that much (which I think maybe it does, but not sure). Because if Stamina effected injuries and gameshape then it would be like a 'doublepenalty'. Players with low stamina should just perform poorly after Xminutes of play. How talented the player they face is may also be fair to include as a factor to increase or decrease the rate the player 'tires'.
RIght now it seems like you can field an all attrocious Stamina team of about 7 players versus a 12 man squad of proficient stamina and it will hardly impact the outcome of the game. Where as if the opponents enthusiasm is 5 and yours is 3 you are almost guaranteed to lose. I would like to see stamina impacting the game, and if it was stated in the game engine when we watched games that would be like WAY WAY COOL. for example "Joe smith gets beat again on the play, he looks tired' 'Joe smith's tank as empty, and his jumper is gone' etc. stuff like that would spice up the playbyplay and add another level of complexity, realism and interest to the game.
My two cents.