The least motion principle is the Occam's razor of chemistry - basically, the less that atoms have to move in space for a chemical reaction to occur, the more likely that reaction is to happen. I found myself wondering if the same idea can apply to positional play in chess...the less you have to move your pieces for a given task, the more likely you are to succeed. Economy of movement is key to attacking chess, but also to positional maneuvering. Sometimes the weakest response to a threat against a piece or pawn is to move it away from the threat, rather than supporting the piece or even ignoring the threat with a counter threat!
A simple example can be seen below, in 'Parsippany Fight Club Part 2' where ...Nf5! ignores the threat of losing the exchange while threatening mate and the win of a rook. Or there is the otherworldly example (position above) from game 4 of the Kasparov-Karpov 1990 world championship match, where the Greatest of All Time leaves his rook on e6 hanging for the next eight moves!
On the other hand there are times when needlessly weakening moves are made in response to perceived threats, and it was a series of those I played in an insipid game where I lost on the white side of the Maroczy Bind. We'll look at this game later this week.