I used to like wrist locks off the figure 4 grip in BJJ. People seemed to defend the armbar possibility and forget the wrist was an option. I'd slide my wrist control hand down over their hand and cinch it all in to get the wrist. Never got them standing but got some on the ground from stalled armbar attempts. Got (jokngly) called "king of the wrist locks" for a few weeks after catching some people. And of course if you catch a wrist lock in BJJ you have to declare "Aikido wins!"