On a completely unrelated and lighter note - I think 13 year old males are the most dangerous animal on the planet.
I give private "pretzel wrestling" lessons to my son and his buddies. Its my underhanded attempt to get my kid involved in the martial arts and its working (cue evil laughter)
Given their utter lack of fear and complete confidence that they are indestructible, they've done a few things that have just strange enough to change.
Early on, one kid improvised a triangle choke on another.
Recently we covered face bars using forearms. Last week, one kid knelt on another's head during a scramble. The kneelee - I thought his brains were going to blow out the top of his skull. The kneeler, after I pulled him off the kneelee said "Isn't that the same as a face bar?".
And they wonder why I won't teach them striking.
Same day, one kid (the kneelee as a matter of fact) improvised a stomach throw (judo's tomoe nage). When I asked him how he thought of that he said he saw it on an episode of...wait for it...Pokemon.
I almost forgot, one kid improvised a "spine lock" that can only be described as the old Boston Crab from professional wrestling when I was a kid (at least that's the only time I've ever seen it).