I don't load or shoot nearly as much as some here. I don't keep track of the number of loadings, but I do inspect each piece of brass. Most of my pistol brass is range pick-ups, so I don't know what most of it saw before I got it. My last batch of .40 S&W, that was in the bottom of the box (so I knew that I was loading it for MY second time) actually lost one due to a loose primer pocket. My rifle brass is separated between HUNTING (perfect, new or ONCE-fired) and RANGE (everything else).
All of that to say, it is easier for me to inspect my brass, than to try to keep them separated into batches based on number of loadings, especially when there is no guarantee how many loadings a piece of brass can take.