The app is designed to facilitate the use of the BlackJack Basic Strategy.
Basic strategy is based upon a player's point total and the dealer's visible card.

Each BlackJack game has a basic strategy, which prescribes the optimal method of playing any hand against any dealer up-card so that the long-term house advantage (the expected loss of the player) is minimized.
If you perfectly follow the strategies outlined in this guide, you
can reduce the casino’s advantage to less than 0.5%, making BlackJack
the most advantageous game to the player in a casino.

Perfect BlackJack strategy has been determined using probability theory and computer simulations which have figured out the best play in each situation.