Judging the decision requires separating practical alternatives from ideas that contemporary technology could not supply. British 13.5-inch and 14-inch weapons deserve consideration because relevant work already existed, including an Elswick 14-inch 45-calibre gun. A 15-inch or 16.5-inch armament was unavailable because nobody had developed those weapons. The counterfactual asks whether the Royal Navy chose well among the options it actually possessed.
Notable Point · 5:00-6:11
Using viable alternatives to judge Dreadnought
A methodological aside shows how feasible counterfactual designs help historians judge whether Dreadnought's actual choices were the best available.