Why a raider might avoid a convoy it could defeat

In the hypothetical example, Bismarck would probably beat an R-class battleship but could take substantial punishment from its 15-inch guns before winning. Damage and delay would expose the raider to torpedoes from convoy escorts or to British capital ships closing on the action. Passing up that convoy could therefore leave the raider free to attack less protected shipping. Scharnhorst and Gneisenau, with 11-inch guns, had still more reason to use their speed to avoid a 15-inch battleship. A faster British battle line is offered as a counterfactual that would have required still more speed from the German designs. Deutschland-class raiders faced the same deterrent, illustrated by comparing an attack on an R-class escort with taking on a hypothetical 1940 equivalent of USS Alaska.