Seagull is a very good akido master. And I doubt he has ever been in a real street fight from two anecdotes, one personal. I was at a beachside restaurant with my then Gf. local resident Steven walked in and sent a drink to her. She sent it back. He walks over and starts sweet talking her. I stand up, go into a loose judo stance and say something classic. He turns, sees my stance and laughs 'And who taught you that.' I told him ( my Soto Zen Roshi who was also Japanese grand champion.)He walked away.
A few months later 3 punks yelled obscenities at his family. He left immediately.
All I know, is I saw Frank Sinatra, who NEVER had any formal training , sock a guy half his age and twice his size for making an anti italian crack one night in Westwood Village near UCLA.
There are any number of sytems. As others have posted, it's your mindset, first and foremost.