A real Japanese sword, as good as the old ones...
 

Oh Man! That just got me, oh it got me good!

I love it, I could not stop laughing, feel bad cause the dude got hurt
but man, oh man .... it got him good.

I see these "practice katanas" at a local fleamarket for $10 USD all day long,
in exactly the same furniture and color wrap as on the video. They are sharp enough to cut the ba**s of a cockroach (really scalpel sharp) but "practical quality" wise in any regard they are absolutely useless.

This video made me think a little: seeing the guy whacking the sword side-wise like that over the table and breaking it easy, of course crappy steel...but do you guys think any of the old blades that are more bridle like lets say maybe indian wootz might break if you hit on side like that?
Does any one have any research on how the old blades mostly break? Is it in direct cut edge to cut edge contact? side hit? or spine to edge?

Wootz blades are definitely more brittle if impact is to the side, and mostly break of direct frontal or side impact. Wootz blades can break if accidentally dropped to the floor tip first, even without any push or effort - they'd just snap (Please do not try it!!! I've seen it happening, and it's quite scary). Their strongest impact zone is direct cutting edge.

Wootz is mighty strange stuff. From my polishing experience, I've noticed quite a variation in surface hardness and resilience (springiness) depending on where they were made. Most Persian and Turkish steel can be shaped with a file, even the cutting edge (although the file will dull eventually because the part that "gives" is the softer matrix in which the harder carbide dendrites or networks are suspended, but those carbides are harder than file steel). Indian wootz varies up to almost "glass-hard". Some blades can be easily massaged back to straightness if they are bent or kinked, others are very stubborn and you don't want to push your luck knowing that there is a tendency for the material to be brittle. If a bent blade does not respond to controlled pressure it's best to leave it as is -- bent is preferable to broke.

I think that it's the sudden shock of impact, especially that causing rapid lateral displacement of the blade, that is most conducive to breakage. Perhaps it is why Indian and Near Eastern swordsmanship seems to steer clear of parrying with the blade (even using the slide or spine for the purpose) and relying on the use of bucklers and other shields for that purpose instead.

Philip, Alex, thank you guys for sharing your experiences and your answers.