Board Thread:Questions and Answers/@comment-26962604-20170729235729/@comment-29735334-20170730005312

High luck ships are usually fit with night battle torpedo cut-in setup, one of the most damaging attacks in the game whose trigger rate is tied to luck. People put these ships at the bottom due to the night battle firing order: from top to bottom. It is hoped that the other ships would clean up any remaining abyssals so that by the time the lucky ships' turn comes, only the boss remains and they would have a clear shot at it with cut-in.