Reverting to the opening moves of the Giuoco Piano, in answer to 3. B to B
4, Black may play (instead of 3. ... B to B 4), 3. ... Kt to B 3. This
constitutes the _Two Knights' Defence_. White may continue with 4. P to Q
3, or Kt to B 3, or adopt a more spirited line of play with 4. Kt to Kt 5.
Black's defences being 4. ... P to Q 4. or 4. ... Kt takes P. We append one
or two leading variations:
WHITE. BLACK.
1. P to K 4 1. P to K 4
2. Kt to K B 3 2. Kt to Q B 3
3. B to B 4 3. Kt to B 3
4. Kt to Kt 5 ...
In the Giuoco Piano, where Black's Knight would be still at Kt sq., this
advance would be bad, because Black could reply 4. ... Kt to R 3, {374}
defending the K B P. Here, however, it is the best move. Black's best
defence is
... 4. P to Q 4
5. P takes P 5. Kt. takes P (?)
Not to be recommended. The best move is 5. ... Kt to Q R 4.
6. Kt takes B P (!) 6. K takes Kt
7. Q to B 3: ch. 7. K to K 3
{375} In order to defend the Knight, which is twice attacked. 7. ... Q to B
3 would be bad policy, for in such case White would play 8. B takes Kt:
ch., B to K 3; 9. B takes Kt, P takes B; 10. Q takes P, with three Pawns
ahead.