To be well-prepared for every possible outcome. We need to cover all bases here—check every office and make sure it's been evacuated. I know I don't have the best grades, so I covered all bases by applying to 15 colleges.

To account for or provide a way to address every possible outcome, scenario, contingency, etc. We need to cover all the bases here—the investigation should explore every avenue. I covered all the bases by applying to 15 colleges.