bigredfish
Known around here
You obviously do not know what the 21 foot rule is. It is about observation time, recognition time, decision time, and reaction time.
It takes time for you to observe that the BG is coming, time to recognize he is a threat/has a weapon, time to decide your response, and time to actually react with that response. So if that BG is less than 21 feet from you when this all 'begins', you will have a very tough time reaching a favorable outcome.
As far as a 'hit' throwing a full charging BG and making him stumble so you can step out of the way? Only in the movies.
Exactly.
See “OODA Loop”