German codes and British intelligence before Jutland

How important were German codes before Jutland?

Very important, although poor use of Room 40's intelligence undermined its value to Jellicoe.

German codes gave British codebreakers an important information advantage before Jutland, but intelligence still depended on the questions asked and the way conclusions reached commanders. A naval officer asked the codebreakers the wrong question and passed misleading information to Jellicoe. Codebreaking alone could not guarantee a sound operational picture. Collection, interpretation, and command communication all had to work together.