Since I haven't been around this week, I'll leave the heavy hitting etymology to someone else, suffice to say that I recognized the word zug from navigating the German railway system in my youth. 

Zugzwänge are a regular feature of my own childish chess-play, but figuratively? In the army I pushed a subordinate to gather evidence and personally walked his paperwork through for a "compassionate stabilization" - guarantee not to move for personal considerations -- that he clearly deserved. 

A few weeks after we succeeded, I was in the First Sergeants office, learning that due to Sgt Smith's (we'll call him) stabilization, and Sgt Jones' earlier stabilization, we're over strength, and you, Staff Sgt Lofton, and your family have to leave a year early. Not quite a zugzwang, but it still rankles me.

Zug is a fascinating word in German. Meanings range from "puff" (like a locomotive), to wanderer, to tractor as a verb. Appears in Zugvogel as migratory bird.

In the senses of traveler, migration, one a bit lost, etc., I wonder if way back in the mists of language trees, Zug was related to the familiar-in-English Latinate prefix fug. As in fugitive.  

Everything about this word, seems to lead back to chess, so who am I to argue:

Zugzwang - Wikipedia

I was in my HS chess club for two years and do not recall ever hearing this word and after today, old age will probably, excuse me... what were we talking about?