The Deadly Chess Symmetry
There is a popular misconception amongst amateur players that a symmetrical position in chess inevitably leads to a draw. We already discussed here why playing a "copycat chess" can be extremely dangerous for your own position.
Yet, there is a grain of truth in the popular belief; a symmetrical position indeed can lead to a boring, uneventful draw. Just check a database and count literally thousands of listless draws played in the Exchange Variation of the French Defense or the Exchange Variation of the Slav Defense.
Nevertheless, in certain situations the best way to take advantage of your opponent's mistakes is to go for a symmetrical position!
Take for example the Slav Exchange. If both opponents put their pieces on their best squares, it can be boring like this:
Neither player could use to his advantage the only open c-file. But imagine that Black's Nc6 was developed to d7. In this case the c-file can turn into a bleeding wound for Black, like in the next game:
This game explains why most chess players recapture 6...exd5 in this opening line. So, it is a good positional idea to keep in mind in the various lines of the Slav Defense: if your opponent developed his Nb8 to d7, check if a timely trade cxd5 forces the opening of the c-file.
In the following game an extremely talented Mir Sultan Khan immediately realized his mistake and even tried to fix it by playing Nd7-b8-c6! Unfortunately it was not enough against one of the strongest positional players of his time, GM Salo Flohr:
Here is one more masterpice from another positional genius: Akiba Rubinstein. Notice how helpless was his opponent (none other than two-time world championship challenger Efim Bogoljubov!).
The Slav Defense is a very popular opening, so if you get an opportunity to punish your opponent for the development of his knight to d7 by opening the c-file, do not miss your chance!