I for one believe this to be an awful policy. No offence. My one bit of advice is, accidents happen. Period. Learn to hold yourself accountable for your partner's mistakes. Don't allow blind rage to get the best of you, especially in a training situation where you are in a group setting and everyone is trying their best to learn. It's a hard concept to grasp I suppose but, your partner kicking you below the belt can just as easily be your mistake as much as theirs. However, if you lose control and nail them full force in the testicles BECAUSE they made a mistake which could have been your fault, then that's on you. Period. And if that's what your instructor promotes, then I hope for his/her sake they have the highest of insurance policies. No cup, I've taken about 5 shots to the groin area in the past 2 years, most with good control, some with none, but my immediate instinct was never to injure my partners/opponents. (I've gotta buy a cup...) Actually, it was to roll around crying hysterically, kicking and screaming, which I also most thankfully avoided doing. Ok, 1-no offense taken and yes I can see how mistakes can go both ways. It could be my fault or my partners, I agree. 2- I take groin shots almost every day, most of the time with no control, but sometimes with some, my style of karate (kenpo) we have individual Techniques that we do, some times we are told to do it fast sometimes we are told to do it slow, so that's where no control comes from!