umm sword vs. unarmed opponent to cut his arm off, thereby un-arming him... if he has a weapon, grenadethrowdo works well...
actually on fightscience they had a demonstration where they had someone jump out at an israeli commando at any point... you could argue that the commando knew it was coming, however if you are an israeli commando your heightened sense of awareness is probably always going to be on, do to just being aware of your surroundings gives you an advantage, so I am assuming it didn't matter if he knew or not.....so the guy jumps out at the commando, with the gun drawn and raised, but before the gun could ****, the israeli commando shot his left arm from his hip, knocked the gun out of line with his head, shot a right elbow to the atacker, if the gun shot off it wouldn't hit him at this point, grabbed the gun and reversed the situation,, all within like 1.3 seconds, it was awesome and i believe he would've known krav maga, being an israeli commando. but if you are not a commando I highly recommend said grenadethrowdo as your primary style... or earlier said run-fu.