A method, apparatus, system, and signal-bearing medium that in various embodiments determine whether to execute a command in a queue or whether to wait until another command or commands completed. The determination is based on a combination of an in-use vector and a scorecard vector. The in-use vector indicates which slots in various queues contain commands. The scorecard vector indicates the dependencies between various queues. In this way, the scorecard vector, and the thus the queue dependencies can be set and modified after the logic that processes the commands has been designed.