[quote=@Zugzwang]
[@Agent B52]

I know that blades can in fact split bullets. Most bullets are designed to fragment, mushroom, and generally do things that make them really good at soft tissue damage and really bad at "not getting cut in half". The idea is that a human WIELDING a sword cannot move the blade to cut/block the bullet. Bullets are too fast and the human mind, let alone the human arm, is too slow in almost every case, ESPECIALLY in a battlefield situation.[/quote]

I only posted that video to demonstrate that the quality of the sword has very little to do with it's bullet splitting abilities. It was intended as a clarification though I should have added that.

[quote=@Zugzwang]I never said the katana was bad at wounding the unarmored. I assumed its use in that field was implied when I said it was a good draw-cutting sword.[/quote]

This point of yours however was not readily apparent. Rather than a specific set of techniques such as draw cuts, it is the way the katana curves that allows it to cut through flesh and light armour so easily. This is also the reason why various types of sabre and scimitars had curves whenever strong armour for whatever reason was not normally encountered. A good example from the Napoleonic wars is the British 1796 pattern cavalry sabre.

((As a short, humorous aside: The 1796 pattern tended to wound and maim rather than kill. Allegedly the French considered this poor sport and petitioned the British to adopt a more lethal design. The British response was a more polite form of 'lolno, working as intended motherfuckers'.))

My point is the very issue that made the katana a relatively mediocre sword, namely low quality materials, is the same issue that made it a viable weapon. A katana-wielder was very unlikely to encounter someone wearing full plate. When they did, usually during the invasions of China or Korea, it tended to not end well for them. I am trying to repeat your first point here: Ancient people were not idiots. The katana was invented and came into vogue in a region where it was very unlikely to encounter anyone with a full set of European quality plate armour.

[quote=@Zugzwang]The katana could really fuck up an unarmored peasant. But, the point is, so can any sword, and so can spears/bows. As such, and for many, MANY other reasons, they were the dominant forces on the Japanese battlefield.[/quote]

While this is true, there is a difference between weapons optimised for the job. Refer to my earlier point above about the use of armour here.

[quote=@Zugzwang]I really should make a point about battlefield weapons, and why spears were so ubiquitous.[/quote]

Please do, I enjoy reading your posts.

[quote=@Zugzwang]An additional note: the katana is a very poor weapon for fighting enemies in full plate armor. This is going to be in another section, but the long story short is: armor piercing becomes pretty much moot once late medieval plate harnesses came into vogue, and the katana lacks a great many qualities that fighting people in armor requires. It has a poor stabbing point. It is curved, so half-swording is less effective. It is short, so it is a rather poor aide to grappling, and its guard is not robust enough to hook, or to really be much help in controlling an opponent's blade.
[/quote]
Agreed.