The British figured out Germany's new radar system in WWII from its name, saving 100's of lives! How did they do it?

Just when the Nazis thought they could get the upper hand on the advancing British with a new bomber navigation system, some British physicist had to go and muck it all up by simply guessing how it worked and countering it before the first rocket flew! Way to rain on Hitler's parade!

The "Y-gadget," also known as "Wotan," was a radio navigation system used to aid bomber navigation by the German Luftwaffe forces in World War II. The British were winning in the Battle of the Beams and began intercepting transmissions regarding this "Wotan" system. R.V. Jones wasn't new to German code words and knew they were used literally more often than not. Turns out Wotan is the German name of the one-eyed Norse god Odin.

Using this knowledge, Jones determined this new system must use a single beam that was based on a distance-measurement system. The guess was right, and the British were able to counter it the moment it went into effect. The beam operated on the same frequency as the BBC's Alexandra Palace television station, which was used to send false signals to the bomber, confusing them and making the bombs completely inaccurate. The system was ditched after a few failed raids.

(Source)