At the start of the war, the Japanese had superior optics which allowed them to see us before we could see them – especially at night. They also had the oxygen based "Long Lance" torpedos with a range that far outstripped that of the U.S. Mark 14 torpedos which were defective anyway.
At Guadalcanal this allowed the Japanese to win several surface engagements. As pointed out, once U.S. radar came on line (and U.S. captains at sea learned to trust and use it) it negated these Japanese advantages.
(But you probably knew all that.)
Valid points that I already knew — but I am pleased to see them stated by a fellow military history enthusiast.