Philidor Defense: Repertoire Preparation
Philidor Defense is a very difficult opening for Black. White's main idea is to build a strong center, and wait for Black to make a mistake. Black has a very cramped game, and White can just sit on his position.
Here is a game by Victor Korchnoi.
The following is the more modern way of treating this opening. No wasteful moves are made by White, and with no effort, white obtains an opening advantage in 10 moves.
If Black tries an early ...exd4, then White must capture with Queen, and transpose into Ruy Lopez: Steinitz Defense. The following two games demostrate the ideas.
