You want to be down wind of the game you are hunting. Which means you want the wind blowing from the deer to you.

If you are up wind of them your scent will be carried on the wind to them and they will smell you much sooner.

Where I live the wind swirls so much that is hard to play the wind. It will be blowing one way, then when you get in your stand and get situated it will either chage or are start alternating on you.

Paul