In Tag Device 1, Meyer tells us to throw the first parry with the outside flat. Why that flat and not the inside flat. Here are some theories.
Transverse Sword Positioning
When you parry from right to left with the inside flat, the sword naturally lines up with your right arm and shoulder. Which means the bulk of your body is between your sword and theirs, which doesn’t make for a very effect parry.
By turning the short edge out and down, thus striking with the outside flat, the sword naturally lines up with your left arm. Meaning most of your body is on the proper side of your sword.
When parrying with the inside flat you have options, oh so many options, in terms of hilt height. You can hold it anywhere from head high to about your knee. With the outside flat you are limited to either the shoulder or head height.
But options aren’t always a good thing. For this parry you really do want your sword high and your arms extended forward. Unlike most parries, this one relies on movement, not static structure, to displace the incoming attack. Having the hilt low and the point high would be like swinging
The outside flat leaves you in a very good position to perform a long edge cut to the other side. All you have to do is push the pommel down and through and the sword naturally follows the rest of the arc, rotating around the right hand.
The inside flat requires you to pull both hands back, which takes more time to initiate, weakens your defenses, and results in a slower cut. I’m not saying it can’t be done, it just isn’t as fast as the cut from the outside flat.
So is the Inside Flat Useless?
No, not at all. If you attack with the inside flat, you have the option to reverse and wrench, creating room for a second attack to the same opening. It would be harder to wrench with the outside flat because the blade has to rotate that much farther.