Not sure what your point is. If you are starting with a stud at the end of the top/bottom plates and sticking to true 16" OC, your studs are centered—measuring from the end of the top/bottom plates—at 3/4", 16 3/4", 32 3/4", 48 3/4". So the last stud goes from 48" to 49 1/2". That means a 4' sheet of drywall butted up…