Nice site! Say you have 4 available star options (1 stars, 2 stars, 3 stars, and 4 stars). Say you have 2 rebid zones. You run out of rebid zones for 4 star hotels and are forced to lower your minimum star rating to 3 stars. In this case, the zones which include 4 stars would be your "dummy zones". But how do you know that you won't get stuck in one of the dummy zones? I didn't really understand the explanation in the main post which tells you how to rebid. Any help would be appreciated.