Me being a yellow belt... I don't have a heck of a lot in the tool box for sparring. I have learned many kicks, and practice them in drills, but just don't feel comfortable using them in a sparring session... yet. So... I get tired/bored of side & turning kicks. Plus.... because of my limited selection of kicks, and being pathetically slow, it's easy for the higher belts to see what's coming and pretty much everything gets blocked. My punches get through at times, but I want to kick. So... I figured he'd never expect me to try a spinning side kick. I set it up with feinting a turning kick, and spun as fast as I could, and couldn't believe when I felt it connect something other than a glove! Then, he doubled over. Crap, I felt horrible. He shook it off real quick, and didn't seem to have any ill effects when we returned to sparring... but I just felt so bad. Still do, hours later. I can actually do this kick at head level... not sure why I went so low. My instructor told me that it was a good kick to try... I just need to get my head around quicker to help acquire a target, and obviously get my kick up higher. He also said not to worry too much about the low blow (he knows I'm taking it seriously), that I was sure to be the recipient of such mishaps as my sparring continues. My sparring partner was very cool about it after class. Even gave me some pointers on my back kick during open floor. But I sure don't like that I did that... will do my best to make sure it doesn't happen again.