Stronger players err less often, and they make smaller mistakes.
Weaker players make more frequent mistakes, and larger ones.
All players make more mistakes in complex positions than in simple ones.
Most players are capable of finding the obvious answer to a violent threat, and therefore make fewer mistakes in normal attack and defense than they do in positions where the objectives are more vague. 
The weaker player in a game should choose an opening that produces a violent confrontation right out of the book moves, and try to play a short game.
The stronger player should choose an opening that leads to a complex game, but in which the real fighting is delayed as long as possible; and is best served by playing a long and complex game. These goals are more important than trying for an opening advantage against the weaker player.
 The inner meaning of "a waiting move" is "give him enough rope to hang himself".
If you have a tendency to do well against strong players and poorly against weaker players, reading this could add 150 points to your rating. Go back and read it again, think about it, and make it a part of your play.
Advantage affects the winning rate because the players make errors, but the player who has the advantage is less harmed by his errors.
ELO ratings affect winning rates because the players make errors, but the stronger player makes fewer and smaller ones.