There is a considerable difference in the constellation of the
pieces depending on whether the game is opened with (1) P-e4, P-
e5 or (1) P-d4, P-d5. These two openings shall therefore be
treated separately. All other openings are related to one of the
above main branches and need little additional discussion.



KING'S PAWN OPENINGS



After (1) P-e4, P-e5 the only Pawn which both players have to
move to enable the development of all pieces is the Queen's Pawn,
which obstructs the Queen's Bishop. Of course, it would also be
possible to secure an outlet for the Queen's Bishop by advancing
the Queen's Knight's Pawn one step; but in the long diagonal the
Bishop is ordinarily not so well posted as the development of the
Queen's Knight to his most natural square, that is c3 or c6
respectively, would block the way of the Bishop. The Queen's
Knight is best placed in the c-file because on the edge of the
board, in the a-file, he has less mobility; less squares are
accessible to him. In order to place him in the d-file it would
be necessary to move the d-Pawn, and as this would also give an
opening to the Queen's Bishop the move of the Queen's Knight's
Pawn is superfluous.

Before moving the Queen's Pawn the players will have to make sure
that in advancing him they will not block the way of any piece.
Consequently, White will not play P-d3 on his second move. He