I ordered some stuff from a Chinese seller on ebay. They sent me the wrong stuff. As usual, they fixed the problem by sending the right stuff and telling me to just keep the wrong stuff. The wrong stuff included a cheap plastic breadboard. One day I actually tried using the breadboard. It was the standard type with 2 upper and 2 lower strips of holes, which I normally use as power rails, and a center section with 700 or so holes. I bridged the upper and lower rails across the middle, because on that size there is often split in the middle. My circuit, though very simple, failed to work. After 30 minutes or so of trying to figure out why, I discovered the upper and lower rails were not split in half but in thirds!