We do a lot of knife fighting too. Even the knife sparring sessions I have won, I ended up with cuts (red lips stick marks from the rubber training knives cover in it) all over me. Very seldom, would I have walked away without needing serious medical attention.

Now, fighting an unarmed man or even an untrained knife wielding man while I have a knife, I think I could do a decent job of avoiding getting slashed too badly before sending him to bed.