kami-shiho-gatame
(upper four quarter)
"This is a very powerful hold and an excelent reason
why you should never let an oponent get behind you.
Once
behind you if he applies the upper four quarter,you will not readily
escape.
Your opponent is lying on his back,you have approached him from
behind his head and are lying extended with your chest on his,
your elbows pressing hard into his armpits,your hands holding
his belt on either side.Your head is turned to one side and you
are pressing down on him;your hips are on the ground.Your legs
should be wide spread equally to either side so that his body
and your legs together form a letter "Y".