question for the contractors out there, R11 vs R13 insulation

[keakar]

so I guess to clarify, is it better to use two layers laid out in opposite directions or just thicker single layer bats? I have actually heard people say that each one of these methods is a "better" way to insulate then the other so im not sure which is the better way.

most cookie cutter construction, I see the two layers used in opposite directions but don't know if that's the better way or just the cheaper way which is often the reason they do what they do with everything.