"Weak points, and even more so strong points, (in short every point which could be described as strategically important) must be overprotected! The pieces which fulfil this duty are rewarded for helping to overprotect the said strategically important points by the fact that they are wellplaced when it comes to undertaking other duties; so to express it somewhat dramatically, the importance of the strategic point envelops them in its halo."
This is beautifully and poetically said, but it remains pretty vague. The book is full of this kind of poetic vagueness. The result is that every author who writes about My System will give his own explanation. Depriving the reader from the subtleties behind it. You really have to read the book yourself!
When I started to dive in the examples that accompanied the text, I found the following nugget:
Overprotection of an important central pawn leads to the following advantages:
- It is impossible for the opponent to attack you succesful at a flank when you have the center firmly in your hands. So it is a prophylactic measure. I already noticed this when playing the kings gambit.
- The higher goal of a central pawn (any pawn, for that matter) is to hit the road and go mobile. As is often said, a well protected pawn stands probably in the way. The square that the pawn leaves behind becomes a pivot point for the (ex-) protecting pieces which become now free.
- And my most important discovery: if a pawn is attacked twice and defended twice, the pawn is not overprotected. The defending pieces are fully committed to the defense. If you overprotect the pawn, you will find that all the pieces become free for other duties. Not at the same time, but you are free which piece to pick for a little temporary tour to do another job. It makes all the defending pieces elastic.