Board Thread:Naruto Discussions/@comment-26107879-20181004003653/@comment-6769189-20181009204812

@combat: Substitution is Body Flicker+fakeout. Sometimes genjutsu is used to enhance the effect. Whenever a character substituted while being held then they werent as secure as they appeared to be.

@Lone: Characters like Lee/Minato/Body Flicker users are capable of training and adjusting their perception to their high speeds because they can constantly move at that speed. Their max speed wont ever suddenly increase so much that their perception cant keep up. There is generally a correlation between max speed and max perception because they grow alongside one another.

Chidori, however, is faster than lightning. The speed of Chidori will always be added to the users max speed and because the increase in speed is so drastic, their perception wont ever be able to keep up.

KCM Naruto literally broke his ankle because he didnt have control over his speed but after some training it wasnt a problem.

A is a special case because his Raiton Armor also increases the speed of his synapses

As for Body Flicker during combat, its possible that the are constantly using body flicker during high level combat.