I'm New to the site, so here's my 2 cents. I've found that when training my boxers that there should always be a slight bed towards your opponent from the hips up. I've found that boxers who stand a little too straight-up tend to get caught on their heels with stiff jabs, and nice straight righthands. This also allows the boxer to absorb the shots better. I'm not saying to bend over a whole lot, but you should be bent slightly at the hips with your chin tucked. This forward lean allows you to utilize your legs for a better foundation, and makes slipping punches much easier. Hope this helps.