Having started out in a JKA (Shotokan) club, and run the gamut through Judo (Kodokan) to Kyokushin and Daido Juku…I’ve pretty much seen it all, with regard to sparring/randori.
JKA: jiyu kumite. Any and all techniques, but with surface contact only. No penetration of any kind. Strikes are pulled immediately upon contact with the opponent.
Judo: Randori. Full contact. Throw them if you can. No striking at all.
Kyokushin: No strikes below the knee or to the major joints. No groin shots. No hand techniques to the face or skull. Throws are occasionally allowed (a association-based variation). Full contact, Knockdown Rules. No pads.
Daido Juku: No ground and pound (simulated only). Wear full helmet. Any and all striking or throwing techniques allowed, including to the cranium and face (which is fairly well protected by the helmet). No intentional joint attacks or groin shots. Full contact.
Which leads us to:
Question: Which approach is optimal for serious martial arts practitioners? Why?
Question II: Do systems which practice no full contact (in the manner of Judo or Kyokushin/Daido Juku) sparring set up their practitioners to fail (as their training is unlike the actual combative environment)?
Question III: Why is sparring of this type so scarce in “traditional” styles? Especially the systems reputed to produce (at one time) superb fighters?
Note: this is not a “traditional vs. MMA” thread. I’m more interested in the reasons behind the current state of affairs.