I can't remember the last time anyone - trained, untrained, drunk, stoned, crazy or just plain pissed off at the world - took the sort of "wild swing" at me that people seem to assume are all we need to deal with. Tweaker last week threw a roundhouse kick at me last week. Not the best, about what I'd expect from one of our mid-level colored belts, but it had good power. No, it didn't land. No, he didn't enjoy the results of the kick. No, I don't think it's reasonable to think that all we have to deal with are "untrained idiots taking wild swings". As others have said, most people have been in fights, or seen enough fights, to have a little idea of what they want to do.
Well, all two (large sample size there...) altercations that I have been in have started with them throwing a big looping right hand punches. Both were drunk and apparently untrained.
Both seemed incredibly slow to me. Part adrenaline, part me being used to skilled sparring partners.