The Ego 80 number is based off the season average.
You don't need to play every game over ego 80. You just have to make a simple season average of 80. My championship winning game was at ego 75.
I am comfortable playing at ego 75. I played my first 9 games in a 16 game season at 75, winning them all. I had a 4 or so game lead on third place (you only need to be one of the top 2 places to make the playoffs). At that point, I upped my Ego rating to 99. I lost the next 5 games (one where I lost 5-1, giving up all 5 runs in the first two innings, yay me). I dropped it back down and proceeded to win the rest of the way out, including playoffs
My average looked like this: ((99*5[games])+(75*15[games]))/20[totalgames]=81 Ego
I don't recommend drastic switches between ratings in the season. Your timing will get messed up for a game or two when you drop back down.
If you have any questions, let me know in a comment. I'll try to get to them whenever I visit this site.