Board Thread:Naruto Discussions/@comment-26107879-20181004003653/@comment-6769189-20181125081328

@ninja of war: admittedly the mechanics of how it boosts speed is speculation on my part but these are the facts as stated in the manga:
 * Chidori makes the user too fast to see counter attacks. Ch 240 p14
 * Chidori is incredibly fast. Ch 240 p2
 * Chidori is impossible to use in combat without the Sharingan. Ch 128 p19