In ‘Strategy and Tactics in Chess’ Dr. Max Euwe gives this game (as a fragment) under the chapter Strategy: Special Principles where he discusses taking the initiative. The initiative is often mentioned in annotated games, but often it’s not understood how to actually use it.
According to Wikipedia the initiative in a position belongs to the player who can make threats that cannot be ignored. He thus puts his opponent in the position of having to use his moves by responding to threats rather than making his own.
Jeremy Silman in his book ‘How to Reassess Your Chess’ defines initiative as 1-when your opponent is defending and you are attacking or 2-where you are placing pressure on his position, then it is said that you have the initiative.
Mark Dvoretsky in ‘School of Chess Excellence 3 - Strategic Play’ defines initiative as imposing your will onto your opponent.
This miniature by Botvinnik is a good example. When he played 10.g4 he was using the initiative to create threats against black’s King. I think the fact that none of the engines I tried in this position even considered it shows it to be a concept that humans seem to recognize but not engines in their cold blooded calculations.
If black had offered a better defense by 18…Nf6 then white’s prospects on the K-side would have been at a standstill. In that case, unlike many players who would want to continue the attack, white would have used his initiative to switch operations to the other side of the board. This little game is a good example of just how important the initiative can be.