Several question come to mind to try and answer your question.
1. What kind/number of deks and what kind of ducks are you after?
2 What size of a body of water? Large lake or small pond or salt flats?
3. What kind of pressure from other hunters?
Me I hunt a lot of smaller ponds mostly for mallards not a lot of competion from other hunters close by, I use 12 to 14 ducks and if it's a goose day at least 3 goose deks. I don't really put them out in any kind of pattern most of the time just a loose bunch. Sometimes I'll make a sort of J with the leg being the farthest away for me to try and draw them closer to the blind but always with the main bunch at the side the wind is blowing from. Just like airplanes they like to land into the wind.