Well yes the sets tires are numbered, but each tire is not.
Since I started running R compund tires in 2000 I am on set 18. The first few were Kumho victoracers. The rest have been RA-1 until now.
I usally keep at least 2 sets in active rotation and it was easy to tell one set from the other due to tread depth. As I worked in set 3 it became harder so I colored each set fo wheels. 1 set standard black, 1 set white and 1 set red.
I used to have each of them numbered, but I found it easier to use colors with the 3 sets.
I have logged every event the car has run since I built it along with ever tire set I ran on it for each session. I can in fact tell you how many sessions the car has run and the approximate length of each one. Plus I have the date of the event, track and approx high temp for the day. For each set of tires I know how many heat cycles, how many races and racing hours. I also know how many months I have used them and also if they were shaved or full tread.
It is actually in a spreadsheet.
So there JIM