Again White's King's Pawn is attacked. The first continuation for White to think of would be (4) B-d3, developing another piece. However, Black can then simply exchange twice on e4 and play P- c5, so that White loses his Pawn center. P-e5 does not seem very good either. It does not lose any time, as Black too has to lose a move retreating with his Knight. But the latter is well posted on d7 from where he assists the contemplated advance P-c5 against White's center. The best continuation is apparently (4) B-g5, which develops a piece and protects the Pawn e4 through pinning the Knight f6. After
(4) B-g5 B-e7
White finally has to either advance the King's Pawn or exchange him. The latter seems preferable. The drawbacks to the advance have been discussed before. After the exchange White can develop his King's Bishop to d3 where he is considerably better posted than the corresponding Black Bishop.
QUEEN'S PAWN OPENINGS
The same two leading principles apply to Queen's Pawn openings which were discussed in connection with the King's Pawn openings; but there is one great difference between the two kinds of openings which is not obvious to the beginner. This is the fact that in Queen's Pawn openings, in most cases, neither player has a chance to open a file in the center of the board through the exchange of one of the center-Pawns, and that, therefore, an additional Pawn move is necessary in the opening stage to provide for an open file in which the Rooks later on may have an opportunity of entering the battle.
In addition, it is in most variations not easy to find a good place for the Queen's Bishop without further Pawn moves, and it is here where the beginner is bound to err in the plan of his mobilization unless he has adequate instruction.
In trying to open a file for the Rooks it will be advisable—just as in the King's Pawn openings—to aim at the same time at the clearing away of the opponent's center-Pawn, and this can only be done by the advance of the c-Pawn. Therefore, it would mean loss of time if the Queen's Knight were developed into the c-file before the c-Pawn has moved; the Knight would have to be moved away again in order to enable the opening of the c-file. This consideration furnishes the key for the understanding of the most popular Queen's Pawn opening, which is
(1) P-d4 P-d5 (2) Kt-f3 Kt-f6 (3) P-c4
White offers a Pawn to induce Black to give up his center-Pawn, hence the name "Queen's Gambit." If Black could actually hold the Pawn he would be justified in accepting the Gambit unless it can be demonstrated that White's advantage in development yields a winning attack. However, White can easily regain the Gambit-Pawn, and so there is absolutely no reason why Black should give up his Pawn-center.
The way in which White regains his Pawn in the accepted Gambit is this: (3) …, Pxc4; (4) P-e3, P-b5; (5) P-a4, P-c6 (if Black takes the Pawn a4, White captures the Pawn c4 and then regains the a-Pawn. (5) …, P-a6, cannot be played on account of Pxb5, opening the a-file for White's Rook so that Black cannot retake the Pawn). (6) P-b3, Pxb3; (7) Pxb5, Pxb5; (8) Bxb5+ and Qxb3.