What is "mindplay"

MindPlay was a technology designed to monitor blackjack players' actions while playing in a casino, first released in 2003 and discontinued in 2007.

Monitoring a person's play traditionally is done visually, by the dealer, floorperson, pitboss, and the eye in the sky (video surveillance). If one of these observers notices something unusual in a person's play, they will do what they can to either

1. determine if the person is a cheat or a card counter, or
2. change the game to turn the odds back in favor of the casino, through more frequent card-shuffling or other methods, or
3. bar a player they think is a card counter, even though the practice is legal.