Another Morphy’s perceptions, which becomes clear in a large number of his games, is that superior development increases in value, in proportion as the game is more open.
Therefore the side with the better development should endeavour as much as possible to shape the game as an open one, whilst it is in the interest of the side with the worse development to keep the game close. I give here some characteristic and illustrative games.
This games gives us an opportunity also of considering the pawn sacrifice as characteristic of Morphy. Thanks to his principle of development, he often had his Rooks and Bishops in play before his opponent had castled. Those pieces require open lines. The early pawn sacrifices by Morphy are directed towards that object, namely, the opening of lines, and are made mostly for positional purposes, without any exact calculation. The following game will serve as an example.
A large number of still more characteristic and, as regards the development of chess technique, more remarkable games of Morphy had this meaning: that his opponent were unacquainted with the principle that the opening of the game was favourable to the side with the better development, and further that those opponents whose development was defective, in advancing pawns with the object of freeing their position only opened up avenues of mobility for the pieces of the other player.