Historical possibility begins with an option decision-makers actually had

Historical possibility is distinguished from free-form what-if invention by starting with an option that decision-makers actually possessed. A concept already being built or prepared for production raises the question of why it was rejected and what it might have produced. The Queen Mary exercise argues that Renown's displacement could support three triple turrets and nine guns while retaining slightly more power than the historical six-gun ship. The simulation illustrates the claim, while the documented availability of triple-turret designs supplies the historical basis for investigation. This method keeps counterfactual analysis tied to choices visible in the historical record.