curve knees..?

I've seen a few variations of curve knees. First being, explosive
from a tight position. There is also the hip swing curve knee which
I don't like because of the time it takes to land. The last is a version
Bas Rutten teaches on his tapes. This entails turning the leg parallel
to the ground so top of the knee hits the target. From is very similiar
to round knee with bent leg and hitting with knee instead of shin. Which of these is most
effective in specific situations?

Really there are only three different knees.

They are the straight/long knee, the curve knee and the Side Knee (aka the Swing curve knee).

Each has their own variation, but all variations fit into those three categories. Even the jumping knees are either straight or curved.



Do you hit with the knee cap on the
swing knee?

P.S.I added the question that was supposed to
be in my original post.

Usually, I hit with the side of the knee, at the very end. You should be aiming to catch your opponent with the knee.

It pisses me off when I see fighters throw side (swing) knees when they have no space between the hips and they are hitting with the inside of the thigh. It is a clear example of misunderstood use of knees in the clinch.

Drawing from my own experience, side knees are best thrown straight after you have just turned your opponent and he is off balance.

Dont try to throw a side knee when your opponent has control over your hips. This is inviting a throw. If your opponent has hip control (ie, his arms hugging your waist) then it is best to smother him by pushing his head back by rubbing your forearms into his face and your hands under his chin.

When he is arched back, you could probably get away with 1 or 2 small side knees to his thighs. At this point the ref would probably break the clinch.

Hope this helps.