Except where the style is inseparable from the sport. Certainly the slam rule in folkstyle will have an effect.
I have met a wrestling coach in the park. He told me that "head lock" is not allowed in his wrestling. I can't remember what kind of wrestling that doesn't allow "head lock". Do anybody know?
Take this post with a sizeable helping of salt but I think it was disallowed in Folkstyle (collegiate) and possibly freestyle. Whatever style it was the reason I remember was that people were dropping the arm across the neck and turning it into a choke.
Because of it's excellent clinch game and upper body control. Check out Karl Tanswell's STAB program for Greco knife defence.
If you take both the head and arm I'm sure that's legal in freestyle and greco. Like this You can also use a headlock to throw into a scarf hold position. The only type of headlock I imagine would be illegal would be like a guillotine or something. That is unless someone has changed the rules whilst I wasn't looking.
A key difference between Greca Roman and Freestyle is, in Greca Roman wrestling you're only allowed to use your arms. In freestyle you can use scissor holds, using the legs to secure a hold. I know that from having had a wrestler bf. I don't know that much about Judo except that its based on Jiu Jitsu and Sumo wrestling.
Is that true or are you pulling my chain...Master kano was not your average sumo bodyshape...or was he?
no judo wasnt formed from Sumo (some aikido techniques were). Judo was formed from different styles of Ju-Jutsu. Grec"o" Roman (french wrestling) allows only upper body grabs while freestyle allows almost anything.
Actually I do believe the kata guruma as well as a few other throws were taken from sumo. While there is a trend towards heavy players in sumo, there is a lot of crossover in techniques from judo to sumo AFAIK. But you're right, it was primarily developed through Kano's experience in JJJ.
i haven't found anything that looks like kata guruma in sumo techniques but maybe i missed it: http://www.japantimes.co.jp/sports/sumo_techniques.html most sources i've read say that kata guruma was taken from western wrestling. but i'm sure that their was lot's of mixing as kano tried to gain the upper hand on other styles. (e.g. fusen ryu matches leading to judoka developing a stronger ground game) theres also a lot of cross over in sumo and greco techniques which has made greco players so adaptable to it like Kotoōshū Katsunori (bulgarian dude) but thats due to the limited number of techniques possible to develop under one ruleset.