A GOOD CHESS MOVE IS FALLOW BY A ! OR !!, DEFINITION PLEASE! ?
What is the definition of a good chess move, how do the author of a book decides to mark a move as a good move fallow by, !, or !!.? WHAT ARE THE RECUIREMENTS TO CLASIFY A CHESS MOVE AS A GOOD MOVE OR EXCELLENT MOVE BY A DOBLE EXCLAMATION MARK?
There are no objective requirements for such a label. In my experience, the ! should be reserved for a move that would probably not be seen by someone looking only 1 or 2 moves deep. For example, if someone leaves their queen hanging, taking it would not merit an exclam "!". Neither would playing a back rank mate or your garden variety two-move mate.
A "!!" would be reserved and used only sparingly-- for a move that is truly surprising and would only be found by 1 in a thousand players. For example, 23 ..Qg3!! in the Gold Coin Game: