Blackjack Strategy Trainer

Basic strategy is the mathematically optimal way to play every possible hand in blackjack. It was originally computed in the 1950s by Roger Baldwin and later refined by Edward O. Thorp using computer simulations of millions of hands. For every combination of your hand total and the dealer's up card, basic strategy tells you the single best action: hit, stand, double down, split, or surrender.

The strategy is derived from expected value calculations. Each possible action is simulated over thousands of outcomes, and the action with the highest expected return is selected. While it does not guarantee you will win every hand, it minimizes the house edge over the long run.

A typical blackjack player using intuition faces a house edge of roughly 3-5%. By following basic strategy perfectly, you reduce the house edge to approximately 0.5% (varies by table rules). That means for every $100 wagered, your expected loss drops from $3-$5 down to about $0.50.

Over hundreds of hands, this difference is enormous. Basic strategy is the foundation that every professional blackjack player builds upon. Without it, card counting and other advantage play techniques are far less effective.

The Hi-Lo system assigns a point value to each card dealt: cards 2-6 are +1, cards 7-9 are 0, and cards 10, J, Q, K, A are -1. As cards are dealt, you keep a running count. A high positive count means the remaining shoe is rich in high cards (favorable to the player), while a negative count means it is rich in low cards (favorable to the dealer).

The true count is the running count divided by the number of decks remaining. This normalizes the count across different shoe sizes. Professional counters adjust their bet size based on the true count, betting more when the count is high and less (or the table minimum) when the count is low or negative.

• Splitting 10s: A hard 20 is one of the best hands in blackjack. Splitting tens to try to get two blackjacks is a negative EV play.
• Taking insurance: Insurance is a side bet that the dealer has blackjack. It pays 2:1 but the true odds are worse. It has a house edge of about 7.4%.
• Standing on soft 17: A soft 17 (Ace + 6) should almost always be hit. You cannot bust, and hitting gives you a chance to improve.
• Not doubling on 11: With a total of 11, doubling down is almost always the correct play. Many players miss this opportunity to increase their edge.
• Playing by "feel": Deviating from basic strategy based on hunches or streaks increases the house edge. The math does not change based on recent outcomes.