Everything you always wanted to know about Zwischenzug.

I can't pronounce zwischenzug and I can't spell zwischenzug so I call it the "in-between move".

What is an in-between move?

In chess, a person's next move is sometimes obvious because he or she must make that move. But the obvious move is not always the best move.

An example from a game I just played: My opponent wanted to exchange queens so he took my queen, so of course I wanted to take his queen. But first I made an in-between move. Instead of taking his queen I took one of his pawns with my knight. I was able to do this because after taking the pawn my knight was checking his king and so my opponent had to get out of check. Then on my next move I took his queen. By doing this I was able to get a free pawn.

This was the game: https://lichess.org/TfqSoOPs/black#0

I had the black pieces and I won the game. My in-between move was my 26th move.

Nobody cares but I think this stuff is interesting. Chess is the best waste of time ever invented.

Wikipedia - Zwischenzug

The zwischenzug (German: pronounced [ˈtsvɪʃənˌtsuːk] "intermediate move") is a chess tactic in which a player, instead of playing the expected move (commonly a recapture), first interposes another move posing an immediate threat that the opponent must answer, and only then plays the expected move (Hooper & Whyld 1992:460) (Golombek 1977:354). It is a move that has a high degree of "initiative". Ideally, the zwischenzug changes the situation to the player's advantage, such as by gaining material or avoiding what would otherwise be a strong continuation for the opponent.

Such a move is also called an intermezzo (Cox 2007:216), intermediate move (Kasparov 2008:208), or in-between move (Burgess 1997:494) (Horowitz & Reinfeld 1954:180–97). When the intermediate move is a check, it is sometimes called an in-between check (Horowitz & Reinfeld 1954:183–85), zwischenschach (van Perlo 2006:479), or zwischen-check (Mednis 1997:270).

As with any fairly common chess tactic, it is impossible to pinpoint when the first zwischenzug was played. Three early examples are Lichtenhein–Morphy, New York 1857; Rosenthal–De Vere, Paris 1867; and Tartakower–José Raúl Capablanca, New York 1924. The first known use of the term zwischenzug, however, did not occur until 1933, when the prolific American chess authors Fred Reinfeld and Irving Chernev used it in their book Chess Strategy and Tactics.