Ball/Regan: Zwischenzug! A Comprehensive Guide to Intermediate Moves (paperback)Master the Surprise Move That Turns Games Around Zwischenzug! is the first comprehensive guide to one of chesss most surprising and powerful tactics: the intermediate move, also known as the intermezzo. This tactic breaks the expected flow of the game and catches opponents off guard but only if you know when and how to use it. Award winning author Natasha Regan and chess coach Matt Ball have studied thousands of games to uncover the most common