Do people have assigned spots in the pits?
Yes. All the traders dealing with a certain delivery month (September, for example) trade in the same “pie slice”-shaped section of a pit. In addition, brokers, who work for institutions and/or the general public stand at the edges of the pit. From this position, they can easily see other traders and have easy access to their runners (who bring orders from phone booths). The locals, who trade only for themselves, stand in the center of the pit.