I would see no reason to doubt any Japanese belief that they had the best torpedoes of WWII. They were about the only country which did proper torpedo research and development between the World Wars.

Although this is admittedly a rather exceptional case, let me recount my favorite "Long Lance" story. It illustrates the very good "anticipated wander" characteristics which Al Wellman cited. On September 15, 1942, US task forces TF.17 and TF.18 stumbled across a patrol line of Japanese submarines from Japanese 1st Submarine Flotilla. The I-19 (Kinashi) fired a full salvo of six "Long Lance" at the USS Wasp (the heart of TF.18). Three torpedoes hit the Wasp, starting fires and completely wrecking the carrier. The other three torpedoes missed the Wasp. One of the three barely missed the USS Lansdowne in TF.18 as the group of three torpedoes raced out toward the horizon. By sheer luck, TF.17 (centered around the carrier Hornet) lay in the path of the torpedoes five miles away from TF.18. The USS O'Brien turned to avoid one of the three "Long Lances" which streaked past its stern, only to be hit by another which slammed into the bow. Although it had hit a non-vital area, the hit was to result in the demise of the destroyer a few weeks later as it was heading to Pearl Harbor (after temporary repairs at Espiritu Santo) to have the damage properly repaired. The bottom dropped out of the ship and it fell apart piecemeal. The other torpedo hit the new battleship, USS North Carolina, causing very serious damage.
Rowher and Hümmelchen "Chronology of the War at Sea 1939-1945" (1992) p. 162
Parkin "Blood on the Sea" (1996) p. 94