Is the format used the least amount of work time will be organized into queues first. Using the least time so get a second order queuing. Three and four until it reached the queue waiting to get.
It is a pattern that takes a little work as possible to get the queue first. The minimum amount of time will be followed by a second, third and fourth queued until an end to queues were waiting.
Is the theme that takes less possible to get the queue first. At least the second will be queued a sequence of two, three and four until the queue for the lead.