I was always confused on how decapping works.
Some ways how I think a person decaps but really I have no idea.
>how hard you hit someone
>Hit a certain spot
>how fast your hits go
Thanks.

Its the same as any dm. If enough pressure/force (from pull, punch, kick etc) is put to the joint, it snaps. simple as that. Easiest way to decap is to apply force straight down or up to the joint. try to get a lot of weight to the motion and it should decap depending on the mod.

Aim for the neck and strike, the head will come off if you do it hard enough. Hitting the head isn't always enough direct pressure, so it's usually better to aim at the fragile neck.

A decap is where you take off the head.
That's obviously what your asking.
But they're going into more detail.

Neck is the (In my opinion) weakest joint on the tori/uke body.
If you aim your foot and the neck and get a slightly fast speed then you are gonna decap uke/tori.