When I first stared reloading about 30 years ago I would keep track (on the back of the box) of how many times the cases have been used. After 4 or 5 reloading cycles, I stopped doing that and now I just reload them over and over. I probably get about 2 split cases per 500 rounds, and simply discard them after firing, unless they are too badly split to fire through a gun safely. If I notice that they are split before they go into the press, I simply discard them. If I had to guess on how many times some of the older ones have been reloaded, I would say around 8 - 10. I do find that the nickel plated cases do not hold up as well as the brass ones, but I do like the way they look.
I also find that in general, the 38's hold up better than the 45acp cases do.
95 percent of my 38's and 45's are loaded on the mild side as they are used to punch holes in paper and that may contribute to why they hold up so long. I do load some to service velocities, but since I do not segregate that brass, I can not say for sure that they are the ones splitting sooner. Basically, unless a case is visibly split, creased or mis-shaped, I see no reason to throw it out prematurely.
chief38