According to principles of probability coordination, such as Miller’s Principle or Lewis’s Principal Principle, you ought to set your subjective probability for an event equal to what you take to be the physical probability of the event. For example, you should expect events with a very high probability to occur and those with a very low probability not to occur. This paper examines the grounds of such principles. It is argued that any attempt to justify a principle of probability coordination encounters the same difficulties as attempts to justify induction. As a result, no justification can be found.