After the withdrawal of Japanese forces from Guadalcanal, the completion of the B29 enabled the US military to carry out air raids on the mainland of Japan. It was necessary to capture Saipan Island to make it an air raid base. This is the reason why the US military invaded the Mariana Islands. All-out war between the two navies was to take place off the coast of Mariana. Japanese planes with a long cruising range and a large number of US military planes clash. Both armies deploy tactics that take advantage of their own strengths. How to take advantage of the momentary chance to win. What is a split-second decision?