The intermediate move (also called an in between move, intermezzo or zwischenzug) is an important tactical rsource. It appears in many chess games, either on the board or in calculations of players, and the idea is very simple. It is an unexpected movement that interrupts an apparently forced tactical sequence and changes the outcome of the game.
Here are a couple of examples:
This next position shows some characteristics which make intermediate moves possible: unprotected pieces and a check in the middle of a sequence:
While it is rare to see a GM oversight because of an intermediate move, it is really common to see beginners games where they overlook this resource. Here are 2 more examples taken from the practice of my students where an intermediate move decides the game:
Here are some tips for recognizing intermediate moves:
• Look for threats of mate (example 2), attacks on the queen and checks (examples 1 and 4). These are very common ways examples of intermediate moves and need to be examined.
• If, in the middle of a combination, both players are left with a threatened piece of equal value, sacrificing it can be a form of intermediate move (example 3).
• It is important to take into account the possibility of a counter by our opponent. (Example 2)
Here I leave you with 3 exercises of intermediate moves and will show you the solutions next time: