Our floor has 4 standard stalls and a handicap 5th stall on the end. So if you walk in and no stalls are taken, which one do you take? I have to imagine the standard should be the 4th stall, as you have 3 empty to the left and the handicap stall to your right. Assuming people don't abuse the handicap stall usage, it's the best chance you have of not being next to a fellow pooper. Others argue stall 1 but that is next to a pee stall so you could get a (more often) pee'er next to you install one. I've been studying these statistics for 3 years and, other than my own trend, I can't figure out what the norm is for other people.