|Me, on the wrong end of an exchange with Keiji Tomiyama sensei: c1978|
I don't teach or encourage students to practise Jiyu kumite, and I'll tell you why; I think it gives karateka a false impression of their capacity to fight. From experience, karateka who spend a lot of time sparring begin to believe they're good at fighting....but that's seldom true! Unless you go toe-to-toe with each other, nothing you do in the dojo will come close to a street-fight, because in the dojo, while there may be aggression, there is no violence.
So, how is it possible to test your fighting skills in the dojo? I've always done it by training in ippon kumite, followed by jiyu ippon, and finally, yakusoku kumite. This allows for the attack(s) to be 'unknown' by the student defending himself, and for his response to be become spontaneous.