The shape fo the spread depends upon the amount of hunters we have in the group, shape of the land, and the wind. We start with a simple U shaped group with the opening into the wind and us in the middle under a magnum decoy. That works fine for 2 guys but it can get pretty crowded when you get a third shooter. We can give our selves more room by making a bigger spread but I don't like to spend all my time (and money) with dozens of decoys. The larger the group the more of a J shape we get. Just angle the J so the widest opening faces the wind. Birds don't like landing over the heads of other birds to land so will almost always come down in the opening. The problem with a large J is that sometimes birds will land outside of the opening and walk to the decoy spread. The J is also a good way of dealing with unreliable wind, the opening faces 2 directions rather than 1 like the U.