Talk:List of destroyers by upgraded maximum stats/@comment-26159628-20150305114028/@comment-25983907-20150305121501

You will know when you reach 3-2, where only destroyers fleet are allowed to reach boss node. Fleet contains any other type than destroyer (battleship, standard aircraft, etc) will send you to North.

Well anyway, torpedo cut-in is when during night battle, you will see DD/CL cut-in with 3 torpedoes (Type A Ko-hyoteki do not trigger torpedo cut-in). Look at the picture. You can find more about this at Equipment Guide and Combat.