I was on the Cold Steel website the other day and noticed a few of the rules for their knife fighting.
1. No intentional stabs to the throat. (this in spite of throat protection required)
2. No kicking or punching.
Why? 2a. No punching or kicking as this weights the contest in favor of the bigger, stronger, heavier competitor
unrealistically
3. No takedowns or throws
4. No wristlocks, strips, joint locks or stripping
Why? Two reasons are given for safety, the third is "you could be stabbed by a shorter, lighter, weaker opponent, then grab his wrist and twist it for a submission...
8. No clinching
12. No hitting with pommel of knife.
Remember, these are padded knives and the participants are all geared up.
As far as I can tell, the result of these rules is something almost, but not entirely
unlike a fight with a knife. All close encounters are weighted in favor of the bigger, heavier fellow, you'd better be willing to fight past a stab. A joint crank may be appropriate. Takedowns, throws, joint cranks, pommel strikes, clinching and throat stabs are par for the course. I really don't have any beef with the rules for safety sake. After all, the competitors are not friends and training partners. They have no basis for trust and you need to keep things safe. But don't tell me that your rules are for "realism".