Blackjack is a card game that pits the player against the dealer. The objective is to get a total card value of 21 or come closer, without going over, than the dealer. Aces count as either 1 or 11, face cards as 10, and the rest of the cards at their index value. Suits are irrelevant. A hand counting 21 on the first two cards is called a “blackjack” and is worth a higher payout than other hands.
In the early 1950s, a group of U.S. Army mathematicians developed a mathematically correct set of rules for the game. This strategy, known as basic strategy, dictates how a player should play every hand. Against a dealer with an ace showing, the strategy advises players to take insurance, which pays out a 2-1 payoff on their original bet if the dealer has blackjack. Insurance is not available in all casinos.
This strategy has made blackjack the most popular casino game, causing initial panic among managers who thought that smart, disciplined players could easily beat them. Eventually, though, the casinos adjusted their house edges to reduce the advantage and blackjack’s popularity waned. The rise of baccarat and sports betting has helped to slow the decline in blackjack’s market share.
A player’s knowledge of the game and their ability to use it properly determines how much they can win. This is especially true for a player who uses a card-counting system. These systems, often called plus-and-minus systems, attempt to keep track of the concentration of aces and 10s in a deck to predict when the odds are favorable for a player to increase their bet size.
These techniques are not foolproof and do not guarantee a profit, but they have reduced the average house edge to about 1% for most games. This is a substantial improvement over the house edge of other casino games, including roulette, craps and baccarat.
In our studies, we used blackjack because it is a relatively simple and familiar casino game. It is also an ideal domain for exploring the effects of unjustified confidence on various psychological and behavioral consequences, including outcome expectations, state anxiety, risk taking, and information search and consideration. We manipulated participants’ confidence levels and found that greater confidence led to larger bets (a measure of risk-taking) and less use of hints intended to improve their playing strategies.
To study this, we recruited introductory psychology students as one of their course requirements. Each participant received a minimum bet of $10 and was told that they would receive a 10% payment for their participation. They were also given a sheet of paper that listed a series of hints for improving blackjack play and told that these hints were generally followed by expert players. They were also permitted to make bets of any amount up to $100 during the experiment. We then analyzed the results to determine how they related to the impact of confidence on these outcomes.