Foxwoods particulars
You wrote -
At Foxwoods, I believe the chips have tiny magnets or electric circuits inside (similar to security devices on CDs) and sensors in the betting circles.
My response -
Wrong. Foxwoods does not use that technology. Too expensive to implement at the present time.
You wrote -
There's a touch screen attached to each felt and a card swiper attached to each one. The pit boss fiddles with it if you move seats at the same table, and I've also seen a pit boss use it to check how long someone who left a marker to reserve their spot had been away.
My response -
Foxwoods used to use centralized terminals in each pit to track players. This was time-consuming and took pits/floors away from the playing tables. When prices dropped dramatically on the thin-line, LCD monitors with the card-swiping attachment, Foxwoods placed monitors on each BJ table. This allows the pit/floor to perform player sign-ins, table-position tracking (used to sign-out players when they leave a table), tracking of buy-ins or chip-ins, chip-ups, and table-history monitoring by just scanning the screen at the table. A better use of person-power. It also allows supervisors to execute checks quickly and facilitates pit/floor change-overs on breaks.
You wrote -
Even if the computer can keep track of bets perfectly, someone would have to keep the count to detect APs. But this make it a lot harder to hide your winnings.
As for checks play, black chips always cause the dealer to call out to the PB, but green, sometimes $400 worth, gets no reaction.
My response -
Your current playing style and winnings or your past history (revealed when your player card is swiped) key scrutiny of you as an AP at Foxwoods. They can always review the security tapes to confirm their suspicions and to check if you are squirreling-away chips (which they sometimes do when their pit/floor 'chip-checks' reveal 'missing' chips). At most tables at Foxwoods, only tables at $25 minimums or below have the dealer call checks-play when chips above green are played and usually that is called only the first time a particular player plays that chip color. For tables above $25 minimum, the first time you play a chip color above that of your starting action (black ($100), purple ($500), orange ($1000), or grey ($5000), the dealer would call black-action, purple-action, orange-action, or grey-action, as appropriate). Once notified that a player is playing above a 'table-minimum' chip color, it is the pit/floor's job to track the action. Again, since the pits/floors at Foxwoods do not wander from their three tables to record player information, they can follow table play pretty closely.