ZugZwang! Compelling Moves

Game strategy 

I remember this from learnings in tactical interactions.   Good overview here. 

Play First and Lose: Zugzwang in Chess, Math and Pizzas  in Quantamagazine

How to win games by going second and leaving your opponent with no good options.

In most two-player games, it is generally better to win the toss and go first. And if you are sharing a pizza with someone and want to have a larger portion, it’s usually better to grab the first slice and pick a really large one. But there are situations in which it might be better to go second. In chess, these situations have a dramatic-sounding name: zugzwang! Our puzzles today explore this up-is-down phenomenon in four different contexts.

Let’s start with chess, which is possible to win whether you go first or second. In the most recent World Chess Championship, the Norwegian reigning champion Magnus Carlsen demolished the Russian grandmaster Ian Nepomniachtchi by a score of 7.5 to 3.5. Out of the 11 games played, Carlsen won four, twice as white and twice as black. The other seven games were drawn.

But though it is possible to win as black in chess, it is well known that getting to move first with the white pieces is advantageous — it’s a little like serving first in tennis. Statistically, based on a large number of games, the odds are about 54%-46% in favor of the player going first in chess. In most chess positions, you can improve your position by making a move. But there are times when the player who has to move can only worsen their position and will eventually lose. This is an example of zugzwang — a German word whose literal meaning is “move compulsion.” Here’s a simple example:    ....