Restraint & Overprotection

In my spare time I've been watching the clips from BBC: The Master Game 1980, and have learned quite a bit. The remarks on the following position made a definite impression on me.

BBC Master Game 1980
J.Nunn

W.Browne
After 12.Kg1-h1

The following comments were made at 6:25 into the first part of the Browne - Nunn video.

Nunn: I need to continue with my counterplay. I'd like to play ...Rb8 here. It doesn't actually threaten ...b5; he's got too many pieces on it. But it does restrain him a bit. It makes it difficult for him to move his pieces away to other squares. So it looks like the best move: ...Rb8. [Nunn plays the move.]

Browne: This is a good move. I was thinking of playing f4 and then Bf3, but then he'll be able to play ...b5. I guess I'll just have to play Petrosian's move, Ra3 with the idea of possibly coming over to the Kingside with my Rook later.

I'm a big fan of the Benoni and know that the sequence ...Rb8 & ...b5 is a standard idea. What I didn't know was that it incorporates a general principle involving restraint: 'It makes it difficult for him to move his pieces away to other squares'. Browne confirms the strength of the idea in his own comment.

This restraint is the flip side of what Nimzovich called 'overprotection': when several pieces are aimed at a strong point, one of them can afford to abandon the strong point because the other pieces are still doing the job. This leaves considerable flexibility for reorganizing the overprotecting pieces in search of other opportunities. In contrast, 'restraint' reduces the flexibility of the opponent's pieces. Now that I know what to look for, I'll watch for other examples of the same idea.