One of the most important – and yet subtle – principles in chess is the Principle of Two Weaknesses. This principle states that while a player is likely to be able to defend a position with a single weakness quite easily, a position with two (or more) weaknesses is typically bound to fall apart.
This principle is important to remember no matter which side of the board you’re on. If you’re defending a position and trying to hold a draw, resist your opponent’s efforts to induce a second weakness in your position. Don’t make unnecessary pawn moves in particular, as these can often open up all kinds of weaknesses: a weak square that might need to be guarded, or an isolated or backwards pawn, for instance. Also avoid allowing your pieces to become “nearly trapped,” or for your king to come under too much pressure. Even if that alone won’t cost you material or lead to you getting mated, the defense of that weakness may end up forcing you to abandon another weak point, allowing your opponent to make progress.
As the attacker, on the other hand, you might find yourself in a position where you feel better, but can’t seem to hammer away at one weak point hard enough to force a win. In that case, it’s up to you to find a second weak point or to create one (perhaps through pawn exchanges or other ways to change the pawn structure) to increase the pressure on your opponent.
By opening up a second front, you’ll expand the battlefield of the chessboard and make it impossible for your opponent to cover all of their weaknesses. This can often lead to spectacular tactical wins that are rooted in this one simple strategic principle!