I. CENTRE GAMBIT
2. P-Q4 PxP 3. QxP Kt-QB3 4. Q-K3 Kt-B3 5. Kt-QB3 B-K2 6. B-Q2 P-Q4!
II. KING’S BISHOP’S OPENING
2. P-Q4 PxP 3. B-QB4 Kt-KB3 4. P-K5 P-Q4!
III. SCOTCH GAMBIT
2. Kt-KB3 Kt-QB3 3. P-Q4 PxP 4. B-B4 Kt-B3 4. P-B3 P-Q4! 5. P-K5 P-Q4!
IV. SCOTCH GAME
2. Kt-KB3 Kt-QB3 3. P-Q4 PxP 4. KtxP Kt-B3 5. Kt-QB3 B-Kt5 6. KtxKt KtPxKt 7. B-Q3 P-Q4!
In no case should Black forfeit his chance of playing P-Q4. It is tempting after 2. P-Q4, PxP; 3. Kt-KB3 to cover the pawn at Q5 by P-QB4, but in that case White would sacrifice a pawn by P-QB3, by this means opening the Queen’s file for himself, and so preventing Black from ever playing P-Q4. Thus, for the loss of a pawn, White has a paramount advantage in position.
For after 4. … PxP, 5. KtxP (Diagram 20) White has developed both Knights, and his Bishops are free, whilst Black has none of his pieces out. P-Q3 must also be played in order to mobilise the Queen’s Bishop, leaving K2 as the only square for the King’s Bishop; finally the “backward” pawn [Footnote: A pawn is said to be “backward,” when it cannot move into cover by another pawn.] at Q3 is open to constant attacks and is difficult to defend.