The Luftwaffe addressed this issue first by using a series of radio beams to direct aircraft and indicate when to drop bombs. Several different techniques were tried, including Knickebein, X-Gerät and Y-Gerät (Wotan). These provided impressive accuracy—British post-raid analysis showed that the vast majority of the bombs dropped could be placed within 100 yards (91 m) of the midline of the beam, spread along it a few hundred yards around the target point, even in pitch-dark conditions at a range of several hundred miles. But the systems fatally depended on accurate radio reception, and the British invented the first electronic warfare techniques to successfully counter this weapon in the 'Battle of the Beams'