Re: Bokken Sparring- Chushin Tani Aikidojo
I've done that with carpenters chalk, it is surprising. The problem with that is how many of those "cuts" were soft touches? It's also hard to assess how many of those may have been fight stoppers, or mere flesh wounds. Or how many of those "wounds" may have been life threatening, but not for another 15 minutes, long after the fight was over. It's too hard to try an replicate "reality".
When making a sparring practice I think it's important to try to figure out the "main goal" of that particular practice and not try to make any one practice all inclusive.
The main goal in this practice is to learn to move in time with your partner, avoiding any serious blows to vital spots, while trying to make a good hit yourself. Failing that, can you control, and disarm or submit.