The answer is YES. I become less creative, less observent and stale if I play too much. Case in point, when I play early in the day I can beat players with much higher ratings than me. But playig game after game causes me to lose to much lower rated players. So, I am starting to take a break  Maybe I won't go from 1335 to 1150. Yes that has happened. I just won't quit because I like to play too much.