This one isn't as difficult as it may look or sound (the Zs are pronounced ts). As explained in Chapter 8, Zwischenzug is a German word meaning “in-between move.” It refers to a situation where one player responds to a threat by ignoring it temporarily in order to threaten something else that is more important. After the more important threat is seen to, the player may come back and take care of the original threat.
More often than not, a Zwischenzug is a check or an attack on the queen. These are threats not easily ignored. Here is an example that happens very early:
1. e4 e5 2. Nf3 Nc6 3. d4 exd4 4. Nxd4 Bc5 5. Nxc6
Black does not have to recapture the knight right away. Instead, he can play the Zwischenzug 5…. Qf6, which threatens checkmate.
Only after White has seen to the checkmate threat with, say, 6. Qe2 will Black recapture the knight.
The early play you have been witnessing is called the opening. Openings are a series of moves by both players that bring about a position each is comfortable with. Chess masters have been playing and compiling openings for hundreds of years, and there are not too many positions you can reach early in the game that some master hasn't at least experimented with at some time or other.
The following opening trap is very interesting because it contains several Zwischenzugs.
1. e4 e5 2. d4 exd4 3. Qxd4 Nf6 4. Bg5 Be7 5. e5.
Black doesn't move the f6-knight, which is under attack, relying instead on a Zwischenzug.
Black expects White to move his attacked queen.
But moving the queen causes trouble. For instance, 6. Qc3 loses to the pin 6…. Bb4, while 6. Qe3 runs into the fork and discovered attack 6…. Ng4. So, rather than defending the queen, White plays his own Zwischenzug.
6. exf6! Nxd4 7. fxe7.
And White gets the queen back after all. But just who profited the most from this series is not quite clear.
A Zwischenzug is simply carrying out the old sports adage “the best defense is a good attack.” Always remember to take a further look at whatever threats are looming after a Zwischenzug, or, as in the previous example, a series of Zwischenzugs. Just make sure you always are aware of each and every threat to check or capture at all times during a game.