This book takes a closer look at the Classic mistakes by amateur players

include: 1. Moving a piece too often in the opening. This is one of the

mainstays which we think relates at least partly to the desire to create

something in the opening, when we would be better advised to focus on simple

development. 2. Impatience. Sometimes amateur players are too eager to change

something when there really is no need. 3. Overgeneralizing. One of the biggest

differences I’ve noticed when comparing professional play to amateur play is that

the former is much more about concrete calculation - you go there, we go here

and so on - whereas an amateur player will have a tendency to overgeneralize

when thinking about a position, perhaps because they are not used to the basic

art of calculation. 4. Cutting variations off too quickly. Amateur players do

not extend their calculation far enough, and thus superficiality tends to kick

in. These and other mistakes are explained in the book. Of course it

should be noted that professional players also make these kinds of mistakes.