LAS VEGAS -- The blackjack tables at the Hard Rock Hotel & Casino were packed with gamblers and casino voyeurs on a recent weekend. But in the Peacock Lounge -- the casino's high-limit blackjack room, with minimum bets of $100 a hand -- the casino enjoyed an added advantage to its already stacked odds.

The reason involves a high-tech chip within a chip that is helping the Hard Rock learn more than ever about every move made by high rollers. Computer chips embedded in the plastic gambling chips communicate via radio frequency with sensors placed under the table. The technology gives the casino's operators a trove of knowledge, including a player's average bet and where each high-denomination chip is at all times.

The new chips are based on radio frequency identification technology. RFID has been in the news as Wal-Mart Stores has adopted it, tracking products from its suppliers' factories to warehouses and onto store shelves. The technology also is used in aerospace and health care to keep tabs on supplies.

In the past, casinos have relied on pit bosses and dealers to continually estimate how much gamblers were wagering, which in turn enabled the casinos to figure out about how much a customer spent overall, and what level of discounts and freebies he or she was entitled to. With RFID, the chips are scanned automatically at each bettor's position, and the data are displayed in real time on a computer behind the table visible to the dealer and pit bosses.

To date, Gaming Partners International has sold about 2 million RFID chips, a fraction of the 18 million chips the company sold just last year worldwide. The RFID chips have a life span of about 10 years.

The chips are embedded with microprocessors made by Philips Semiconductors; each has a unique serial number. Radio antennas strategically placed throughout the casino can track the location of individual chips as they move from the vault to the cashier's cage, onto the casino floor and as they arrive at specific tables.