Blackjack table

With a hard 19 against dealer's 7, standing is optimal. A 7 is a dealer bust card (dealer must hit soft 17 and has high bust probability), and 19 is already a strong hand that wins in most dealer outcomes. Doubling would be greedy and unnecessarily risk losing a winning hand.

With a hard 12 against dealer's 10 (Queen), hitting risks busting on any card 10 or higher (16 cards in the deck). Standing gives the best probability as the dealer will likely bust or we lose anyway; doubling down would only increase the loss when bust is likely.

With 14 against dealer's 4 (a bust card), standing is optimal. The dealer has a 40%+ bust probability, making it better to avoid the 46% bust risk from hitting.

With 16 against dealer's 6, standing is optimal. The dealer's weak upcard (6) gives a high bust probability, and hitting 16 risks busting immediately. Basic strategy recommends standing in this spot.

With a hard 9 against dealer's 7, doubling down is optimal. The dealer's 7 is moderately strong but beatable, and doubling maximizes expected value when we have a favorable position.

With 14 against dealer's 10, hitting risks busting (any card 8+ busts). Standing gives the best expected value since the dealer must hit to 17+ and has a reasonable chance of busting or pushing.

I have a soft 19 (Ace + 8), which is an excellent hand. Against a dealer's 3 upcard, standing is the optimal play. The probability of improving is low, and risking busting or ending up with a worse hand is not worthwhile.

Splitting 8s against a dealer 9 is a standard blackjack strategy play. A pair of 8s totaling 16 is one of the worst hands, while two separate 8s give better winning potential with possible 18s or 19s. This significantly improves expected value compared to hitting or standing on 16.

With 18 against dealer's 9, standing is correct. This is a strong hand that beats many dealer outcomes, and hitting risks busting or reducing equity significantly.

With a hard 15 against dealer's 9, standing is optimal. Doubling down risks busting (need to draw a 6 or lower), and hitting has poor odds given the dealer's strong upcard. The first hand already has 18, so this conservative play protects against further losses.

With a soft 17 (Ace-6) against dealer's Jack, standing is optimal. Doubling risks busting on a 10-value card, and the soft 17 already gives a reasonable chance against the dealer's strong upcard.

With a hard 14 against dealer's 4 (a weak upcard), standing is correct. The dealer has a high bust probability from a 4 upcard, and hitting my 14 risks busting immediately with many cards in the deck.

With a hard 17 against dealer's 8 upcard, standing is the mathematically correct play. The dealer must hit on soft 17, and 17 is a strong hand that beats most dealer outcomes (bust, 16, or lower). Doubling would be too risky.

With a hard 9 against the dealer's weak 3 upcard, doubling down is the mathematically optimal play. The dealer is in a vulnerable position, and doubling allows us to maximize value from this favorable situation.

I have 19 (9+J), which is a strong hand. The dealer shows a Jack (10-value). Standing is optimal here since 19 beats most dealer hands and hitting risks busting with a very strong total.

With a hard 8 against dealer's 5 (a bust card), doubling down maximizes expected value. The dealer is in a weak position and likely to bust, making this an aggressive but mathematically sound play.

With a hard 17 against dealer's 8, standing is optimal. The dealer has a strong upcard (8), but hitting a hard 17 risks busting with a high probability (69% chance of drawing 5+), while standing gives the best expected value in this situation.

With a hard 18 against dealer's 6 (a weak upcard), standing is optimal. The dealer has a high bust probability from this position, and hitting risks busting my strong hand.

With 13 against dealer's 3 (weak upcard), hitting is optimal. Dealer's bust probability is high, but my 13 is too weak to stand—I need to improve my hand. Doubling risks too much with low probability of reaching 21, so hitting gives the best expected value.

With a hard 17 against dealer's 3 (weak upcard), standing is optimal. The dealer must hit to 17 or bust, and hitting my 17 risks busting with high probability while offering minimal expected value gain.

With 12 against dealer's ace (which counts as 11 for soft hand calculation), hitting would bust on many cards (10-value cards). Standing avoids immediate bust risk and lets the dealer play out their hand. Doubling down on 12 is disadvantageous given the dealer's strength.

With 15 against dealer's 5 (a bust card), standing is optimal. The dealer has a high probability of busting, and hitting risks busting myself with any card 7 or higher.

I hold 19 against dealer's ace. While the dealer could have blackjack or 20, standing on 19 is the correct play as hitting risks busting with minimal reward potential.