Who's counting? Real-time blackjack monitoring for card counting detection

This paper describes a computer vision system to detect card counters and dealer errors in a game of Blackjack from an overhead stereo camera. Card counting is becoming increasingly popular among casual Blackjack players, and casinos are eager to find new systems of dealing with the issue. There are several existing systems on the market; however, these solutions tend to be overly expensive, require specialised hardware (e.g. RFID) and are only cost-effective to the largest casinos. With a user-centered design approach, we built a simple and effective system that detects cards and player bets in real time, and calculates the correlation between player bets and the card count to determine if a player is card counting. The system uses a combination of contour analysis, template matching and the SIFT algorithm to detect and recognise cards. Stereo imaging is used to calculate the height of chip stacks on the table, allowing the system to track the size of player bets. Our system achieves card recognition accuracy of over 99%, and effectively detected card counters and dealer errors when tested with a range of different users, including professional dealers and novice blackjack players.