Seki Nobuhide Sensei, a martial arts and katana instructor, rates portrayals of samurai battles in movies and TV shows. He explains why samurai employed different types of spears in battle in "Shogun." He breaks down the differences between samurai and ninja fighting techniques in "The Last Samurai," starring Tom Cruise and Ken Watanabe. He describes how to best anticipate your opponent's moves in "John Wick: Chapter 4," starring Keanu Reeves, Donnie Yen, and Hiroyuki Sanada. He weighs the pros