I'm sure if the boxer knew that kick's would be involved, then he'd have the common sense to breach the distance. A fair point, but most amatuer boxers aren't really that good at doing this. They're used to closing a much shorter gap (hence the difference in footwork)If you start putting sweeps into the equation it gets sticky for the boxer. Most boxers don't have a very good lower body defense - because they don't need to. I when I first started Martial arts, I was invited to watch a night of competition fights. One of the fights being hosted that night was a Tae Kwon Do practitioner against a Boxer. I've never done TKD so I can't comment. However most Goju & Shotokan karateka are fairly useful at punching range, they can hit just as hard and as fast. Of the boxers I've trained with I could hold my own quite easily in the hands department and I've trained with some good ones. Also once the range shuts down completly, we're talking judicious use of elbows and knees by the karateka. Again from a tactical point of view, the boxer simply won't be used to this. He won't have a solid game plan to counter them. Apart from rabbit punches he's in a 'no-technique' zone, which is the worst place to be.