I remember that there were like 13 caps, 10 caps, 9 caps, 8 etc. Now there is only 3, 4, 12 and 13. What happened to the rest?

10, 9, and 8 were obsoleted by better capture counts. The current subcategories are defined by restrictions like version and mode that overrule the goal of minimizing the capture count, while 9 captures was only believed to be optimal because better strats were not yet found.