A friend who does Aikido says it's not explicitly taught quite like that - but that he does train to watch, for example, an attackers shoulders for slight movement prior to their attack.
I don't know any martial arts, but it reminds me of basketball - dribbling is exactly the same - every second you decide to start or not, you can make fake moves, and your oponent has to guess and react faster.
And if his guess is wrong he allows you to pass him.
Sometimes you can just feel the rythm in which oponent will react, and then passing him is easy and pleasurable at the same time. And looks cool. That's why I love basketball :)
It's the same in [association] football, rugby, volleyball, netball, [field] hockey. Presumably true in other sports too - so is that really why you love playing basketball?
Having the body control to produce false, seemingly involuntary signals - while suppressing true involuntary signals - implies a level of physical mastery to the extent that you, likely, already possess a substantial advantage in the bout. This is like selling a fake tell in poker while not actually having a tell - even James Bond would tell you that's hard.
You could just sell enough fake tells--produce enough false signals--to throw your opponent off of whatever actual tells you have. I wonder if this is similar in concept to the "drunken" kung fu style.
Sometimes you can just feel the rythm in which oponent will react, and then passing him is easy and pleasurable at the same time. And looks cool. That's why I love basketball :)