I’m a bit late to the party, but I’m about to blow holes in everybody’s theories.
Stand by for broadside! 
Hood vs. Bismarck. Iowa vs. Yamato. Montana vs. H39. So many battleship scenarios, whether real or imagined. But who would have prevailed?
It’s not as easy as you think. Time and time again, I see this scenario, question, poll, etc. played out countless times on naval websites and forums. Too many times, people seem to think that just because the Yamato (or some other ship) had bigger guns, or better armor, or better radar, etc., that that ship would have prevailed in battle. Too many times, people seem to base their arguments on just ONE point (or maybe a few) without looking at “the bigger picture” so to speak. Just because a ship has bigger guns, or thicker armor, or better fire control, etc. does NOT necessarily mean in any way the ship will win. Or as an old phrase goes: “Bigger does not necessarily mean better.”.
Other factors need to be considered in a battleship vs. battleship fight. Things such as, but not limited to:
a) Propulsion, speed, and maneuverability of the ship.
b) Location, weather, and sea conditions of the battle area.
c) Strategies and tactics used by the crew.
d) Skills, experience, and training of the ship’s crew.
e) What is the morale level of the crew? Good or bad? Do they have that “fighting” spirit?
f) How good are the radars and fire control systems?
g) Armor thickness of main belt, decks, gun turrets, etc.
h) Damage control systems?
i) How fast can the ship’s guns be loaded, elevated, and trained on target?
j) Time of flight for the main gun shells to reach their target. Seconds or minutes?
k) How near or far away are the battleships/fleets that are fighting each other?
l) Who is commanding the battleships and/or the main task force?
m) Do the battleships have any escorts and/or air cover with them?
I find it funny how a lot of people say in their comments that “technology” (Guns, radar, armor, or other hardware.) is the main deciding factor. No, it isn’t. Granted, having better or more “technology/hardware” will help, but it ultimately comes down to the “human element” that is using that technology to gain the upper hand so to speak on an adversary. A 16" gun, radar unit, searchlight, torpedo launcher, etc. are all tools. And like any tool, it takes a good skilled, trained, and experienced person to use it effectively and efficiently. Without good skills, training, and experience of the crew, the individual “tools” used on the ship, or even the “whole” ship itself, will not be at it’s best.
And of course, let’s not forget all the people who designed and constructed the ship and all it’s systems. How good were their skills, experience, and training? And how good were the factories, drill presses, and other machinery that made all the steel and parts/systems for the battleship?
PEOPLE are what makes a ship (or anything else) great. Not the gun, radar, or anything else. Too many times, I’ll hear people saying “The Yamato is the greatest battleship ever.” or “The Yamato’s 18” guns were the greatest ever produced." or some other comments. So what? Big deal.
Having the largest battleship in service does not make it great.
Having bigger (or more) guns on your ship does not make it great.
Having a thicker armor belt on your ship does not make it great.
Having a faster speed does not make your ship great.
And on and on I could go. A ship doesn’t win a battle all by itself. It takes a good crew who knows it’s systems and can operate it effectively and efficiently that will come out on top.
And last, but not least, if people are basing their whole argument/debate on just ONE point such as the ship having bigger guns, better radar, etc., then you’ve just immediately lost your entire argument. If you are going to compare 2 or more ships (or tanks, aircraft, cars, or anything else), then you need to consider EVERYTHING about those items. The PRO’s and the CON’s. Educate yourself about not only the object you are trying to discuss, but also your opponent’s too. Trying to win a debate/argument with just ONE point makes you look weak, foolish, and you didn’t do your research.
I mean, what’s the point of even talking to someone if they just blindly shoot their mouth off by saying “The Yamato will automatically win because it has bigger 18” guns!" and that person not considering all other facts, options, and information regarding those 18" guns…or the other person’s ship/systems as well? You’ll just end up wasting not only your own time, but somebody else’s as well. Do your research, folks. Knowledge is power. 