5. ........O - O
Black follows the same line of reasoning.
6. P - Q 3P - Q 3
These moves have a two-fold object, viz.: to protect the King's Pawn and to open the diagonal for the development of the Queen's Bishop.
7. B - Kt 5
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A very powerful move, which brings us to the middle-game stage, as there is already in view a combination to win quickly by Kt - Q 5. This threat makes it impossible for Black to continue the same course. (There is a long analysis showing that Black should lose if he also plays B - Kt 5.) He is now forced to play 7...B × Kt, as experience has shown, thus bringing up to notice three things.
First, the complete development of the opening has taken only seven moves. (This varies up to ten or twelve moves in some very exceptional cases. As a rule, eight should be enough.) Second, Black has
