According to the IBJJF, knee-on-belly happens:
When the athlete on top and free of the opponent's guard, places the knee or shin (closest to the opponent's hip) on the opponent’s belly, chest or ribs, without the opposite knee touching the ground, maintaining the position stable for 3 seconds, while the opponent is lying on his/her back or side.
As far as I know, this position exists only in Brazilian Jiu Jitsu. I'm curious to know what the origin of this position is. Different positions like mount and back-take, knee-on-belly look to me like they originated from Jiu Jitsu.


