HMS Dreadnought versus USS Alaska

Which ship would win, HMS Dreadnought or USS Alaska?

Probably Alaska, although Dreadnought's period battleship armour and unusual combat record make her more than a token opponent.

Alaska probably wins, though HMS Dreadnought is not helpless. Dreadnought carried battleship-grade protection for her own period, which gives her more resilience than a simple age comparison suggests. Her wartime record also includes ramming and sinking a submarine, an unusual achievement for any battleship. The comparison combines real protection differences with a deliberately playful allowance for the older ship's apparent luck.