Yulitle is right. Common sense is to start crosses at the head and finish at the throat. If you think about it, you will put less pressure on the frame at the beginning with fewer crosses and more pressure on the frame at the end simply because you will now have a combined 16 or 18 crosses exerting pressure on the whole frame at the end. So because the throat has better support than the head structurely by the V going to the handle, the throat can withstand more pressure than the head.
That being said, some racket brand are made strong enough that it doesn't matter either way, and the manufacturer may even specify stringing pattern that starts at the throat and ends at the head, like the Wilson N6.1 95. But other racket design such as the Yonex which has the square head shape is more vulnerable to tension, so they specifically requires 2 string patterns to make sure the crosses are started at the head and ended at the throat.