Blackjack · 20 rounds · Sep 25, 2026, 8:38 PM UTC
Round 20
Dealer
Round 20 result · Dealer 21
Claude Haiku 4.5
Hand 1 · 10 · bet 10
Loss -10
With a hard 18 against dealer's 4 (a weak upcard), standing is optimal. The dealer's 4 is a bust card with high probability, and my 18 is strong enough to win without taking the risk of busting.
With 15 against dealer's Ace (which shows strength), hitting carries significant bust risk (any card 7+ busts). Standing preserves the 10-chip bet and avoids doubling down into a weak position against a strong dealer upcard.
With a hard 13 against dealer's 8, hitting is the mathematically optimal play. The dealer's 8 is a strong card, and standing on 13 puts us in a weak position. We need to improve our hand, and the bust risk is acceptable given the dealer's strength.
With a hard 9 against dealer's 5 (a bust card), doubling down is the mathematically optimal play. The dealer is likely to bust, and doubling maximizes expected value in this favorable situation.
With a hard 12 against dealer's 8, hitting risks busting (any card 10 or higher busts). Standing gives a reasonable chance that the dealer busts on their stiff hand, which is the mathematically optimal play in this spot.
Player holds 16 against dealer's 10 (Ten). Standing is optimal here because hitting 16 against 10 has a negative expected value (approximately -0.52); doubling down would only worsen the outcome. Basic strategy dictates standing in this unfavorable situation.
With a soft 13 (Ace-2) against dealer's 8, hitting is standard basic strategy. The soft hand allows us to improve without bust risk on the next card, and doubling here is suboptimal given the weak starting total.
With a hard 13 against dealer's 8 (strong upcard), hitting is the mathematically correct play. The dealer's 8 likely makes 18, so I need to improve my hand. Busting risk is acceptable given the dealer's strength.
With a soft 19 (Ace-8), this is already a strong hand against the dealer's 6 upcard. Standing maximizes expected value since hitting risks busting or only marginally improving to 20 or 21, while the dealer's weak upcard makes it likely they will bust.
With a hard 15 against dealer's King (10-value), standing is the optimal play. Hitting risks busting (any card 7 or higher busts), while the dealer's likely stiff hand (10+5 or similar) gives standing a better expected value than doubling down on this weak hand.
With a hard 10 against dealer's 6 (a bust card), doubling down is the optimal play. The dealer is in a weak position and likely to bust, while a hard 10 gives us excellent potential to improve to 20 or 21 with a single card.
With a hard 10 against dealer's weak 3, doubling down is the mathematically optimal play. This gives us the best expected value by maximizing winnings against the dealer's likely bust hand.
With a hard 20 against dealer's 9, standing is optimal. A 20 is a strong hand that wins against most dealer totals, and hitting risks busting while doubling wastes chips when the hand is already excellent.
With 16 against dealer's 3, standing is optimal. The dealer's weak upcard (3) suggests a high bust probability, making it better to avoid the risk of busting on a hit when dealer is likely to bust themselves.
I have 20 (Jack-Queen), which is an excellent hand. The dealer shows a Jack (10-value card). Standing on 20 is optimal strategy as hitting risks busting with very little chance of improvement, while the dealer's strong upcard makes this a favorable position to hold.
With a hard 14 against dealer's Ace, hitting risks busting (any card 8+ busts). Standing gives the best expectation; the dealer must hit soft 17 or lower, and my 14 has a reasonable chance to win if dealer busts.
With a hard 7 against dealer's King (10-value card), hitting is the correct basic strategy play. The dealer is in a strong position, so I need to improve my hand significantly. Doubling on 7 is unfavorable here; I should hit to try reaching 17 or higher.
With a hard 13 against dealer's King (10-value), hitting is the mathematically correct basic strategy play. The dealer's upcard is strong, so standing on 13 is too weak and will likely lose.
With a hard 19 against dealer's King (10-value), standing is the correct play. My hand is strong and unlikely to improve; hitting risks busting while the dealer's upcard suggests they likely have a strong hand.
I have 14 against the dealer's 8 (a strong upcard). Basic strategy dictates hitting 14 against dealer 8, as the dealer is likely to make a strong hand and my current total is too weak to stand on.
With a hard total of 20 against the dealer's 8, standing is the optimal play. This is a strong hand that wins against most dealer outcomes, and hitting risks busting or reducing the win value.
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Session result: -25 chips over 20 rounds
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