Re: Knees Bent
knees bent - i call it "sitting down on an invisible bar stool."
it is very important. If you are sitting down, you punch with much more power, your feet are dug in, and your base is stronger. Also, you are lowering your center of mass, making you able to move around faster.
Conversely, straightened legs raises your center of mass, lessens your power, and makes you more easily knocked off balance.
It takes time to get used to it. After years of boxing, I had a new coach who taught me to sit down (bend me knees more). For a few months it was very exhausting to my legs. It's like doing isometric wall-sits for hours on end. Well worth the struggle, however. I hit much hard now, I move my head faster, and I can move around faster.