Board Thread:General Discussion/@comment-28934167-20160705151021/@comment-27846412-20160705162148

This is nothing weird. Whenever a event with the slot feature occurs the amount of duels increases. This is due to that after finishing a battle (of any sort) slots may appear and since duels only have a 3 minutes long cooldown period it is an excellent choice as you do not have to use any items or spend a lot of time on it.

Hope this helped!