German naval historian Gerhard Koop states "With the exception of Germany, all sea powers used the 'all or nothing' protection system for modern capital ships, while the designers of the Bismarck and Tirpitz based their plans on the Imperial Navy's final development of the genre, Baden and Bayern, whose protection had been an improved version of that of their predecessors which saw combat at Jutland in 1916. In the time since the Bayern class, German capital ship construction had been an impasse: no experience had been gained, and no test and experimental facilities set up.