Expressions used in Everyday Spoken English in Social and Professional contexts
If you 'cover all bases' you are ensuring that every possibility is considered and that you have planned in advance for any eventuality. You might use this idiom when planning an event for example. "I have ordered gluten-free pizza and vegan pizza to cover all the bases!" It is often used in situations where you are expected to prepare in advance such as a legal issue or a debate. "Let's have the witnesses statements to hand to cover all our bases." This is an idiom that can be used in social and professional contexts.