while I was in town. It appears that the tracking mechanism is in (or actually underneath) the rack.

The rack is much bigger than normal and made of plastic. It extends out from the area necessary to hold the chips and is raised up off the table about 1/2 to 3/4" all the way around the rack, facing the chips and the rails. Nobody in the pit was giving info freely on the thing, but the dealer made a point of telling folks to keep their hands behind the betting circles and away from the chips once she was ready to deal.

I know we talked about the rails before and I wondered how that was possible with stacks of chips, hands, elbows, drinks, etc. being on the table between the rail and the betting circle.

As I said, since no one wanted to talk about it, this is just from observation. It looks like the tracking mechanisms are underneath and around the rack.