They are assigned sequentially. I assign the number when I scan the chip. The CG number ends up being the name of the scan.

Now, here is the rub. I currently scan every chip that I add to my collection. It wasn't always that way. In fact, I still have 378 chips in my collection that are in my database, but have not been scanned and do not have a CG number assigned. For the most part, I have scanned and assigned a CG number to every chip that I have acquired since mid 1996.

I first created my personal database in April of 1995. I had about 100 chips already and had no need yet for CG numbers as I hadn't started chipguide.com yet. In early August 1995, I started chipguide.com and began scanning the chips and giving them a number. I started with Iowa and the first chip, CG0001, is the $1 from Lady Luck, Bettendorf, IA. That was the 285th chip I added to my collection, yet it's CG# is 00001.

So, I went state by state adding 1 state at a time. Here is where the number get screwed up. For example, I started adding California to chipguide.com in late 2002. There were lots and lots of CA Indian chips in my collection that I had not yet scanned. This causes them to have a number much higher then it would be had I scanned them when I got them. Here is an example. The $1 Casino Morongo, CG12467, was the 36th chip I added to my collection. It was added to my database in April of 1995, but has a CG number of 12467, because I didn't scan it at the time I got it. I didn't scan it until I added California to chipguide.com.

So, as you can see, once I get an area established, yes, you could pretty much gauge the time of issue by using the CG number.

Geez, what a ramble. I hope it makes sense.