Blackjack · 20 rounds · Sep 25, 2026, 8:38 PM UTC
Round 20
Dealer
Round 20 result · Dealer 22
Claude Haiku 4.5
Hand 1 · 20 · bet 10
Win +10
With a hard 11 against dealer's 7, doubling down is optimal. This hand has strong potential to reach 21 with any 10-value card, and doubling maximizes expected value against the dealer's moderately strong upcard.
With a hard 17 against dealer's Queen (10-value), standing is the correct play. Basic strategy dictates standing on 17 versus any dealer upcard, as the probability of busting on a hit (69% chance) far outweighs the potential gain against the dealer's likely 17 or better.
With a hard 8 against dealer's 9, hitting is the mathematically correct play. The hand is weak and needs improvement; doubling with only 8 versus a strong dealer upcard would be suboptimal given the low probability of reaching 18 or 19.
With 16 against dealer's 9, hitting is the correct basic strategy play. The dealer's 9 is a strong card, and standing on 16 would lose most of the time. Hitting gives a chance to improve to 17 or higher, or bust but that's better than the high probability of losing with 16.
Hand total is 19, which is a strong hand. Dealer shows 9, which typically results in 17-19. Standing on 19 is the optimal play as the bust risk from hitting far outweighs the small chance of improvement.
With a hard 18 against the dealer's Jack (10-value), standing is the optimal play. A hard 18 beats most dealer hands except 19 or 20, and hitting risks busting with very low probability of improvement. Splitting 9s against a 10 is disadvantageous, and doubling offers poor risk-reward.
With a soft 14 (Ace-3) against dealer's 8, hitting is the optimal play. The soft hand cannot bust on the next card, and we need to improve to a competitive total. Doubling would be too risky with only 14 against a strong dealer upcard.
With 14 against dealer's 8, hitting is correct basic strategy. The dealer's 8 is a strong card, and my 14 is too weak to stand against it. I need to improve my hand.
With a hard 14 against the dealer's King (10-value card), hitting is the correct basic strategy play. The dealer's likely total is 20, so standing at 14 loses; hitting gives a chance to improve to 17+.
I have 18 against dealer's King. Since the dealer shows a strong upcard (10-value), standing on 18 is the correct basic strategy play, as hitting risks busting with a high probability while 18 is a strong hand.
With a hard 18 against dealer's 2, standing is optimal. The dealer's weak upcard (2) means they'll likely bust or reach 17-18, making my 18 a strong hand. Doubling would be too risky for minimal expected gain.
With a hard 9 against dealer's 9, doubling down is the optimal play. This hand has strong potential to improve to 19 or 20 with a 10-value card, and doubling maximizes expected value against the dealer's medium-strength upcard.
With a hard 10 against dealer's weak 3, doubling down is optimal strategy. The dealer is likely to bust with a stiff card, and we maximize expected value by doubling our bet in this favorable situation.
With a hard 19 against the dealer's 3 (weak upcard), standing is optimal. A 19 is a strong hand and doubling risks busting or receiving a card worse than 10, making stand the mathematically superior play.
With a hard 7 against dealer's 2 (a weak upcard), hitting is the mathematically optimal play. The hand cannot bust on the next card and needs improvement to compete with dealer's potential stiff hand.
With 13 against dealer's 2, hitting is optimal. The dealer's weak upcard (2) suggests they may bust, but my 13 is too weak to stand. Basic strategy dictates hitting all totals 13-16 against dealer 2-6.
With a hard 17 against dealer's 2 (weak upcard), standing is the mathematically optimal play. Hitting risks busting while the dealer is likely to bust with their weak starting position.
With 14 against dealer's 9, hitting is the correct play. The dealer likely has 19 (9+10-value card), making stand too risky; hitting gives a chance to improve to 17+ or bust and end the hand quickly.
I have a hard 18 against dealer's 9. Standing is the mathematically correct play; hitting risks busting (any card 4+) while my hand is strong enough to potentially win.
With 14 vs dealer's Ace (assumed 11 or 21), hitting risks busting (any 8+ busts). Standing preserves the hand as dealer must play by fixed rules; probability favors standing here against this strong upcard.
With 16 against dealer's Queen (10-value), hitting is the statistically superior play. While doubling is permitted, the expected value of hitting is better than doubling on this unfavorable situation, as we need improvement and accepting one card via double would commit more chips to a weak position.
With a hard 13 against dealer's 10-value card (Jack), hitting is the optimal play. Standing on 13 loses to most dealer hands, while hitting gives a chance to improve to 17+. The risk of busting is acceptable given the dealer's strong upcard.
Holding soft 15 (Ace-4) against dealer's Queen is a favorable doubling situation. The soft hand allows me to improve without bust risk on one card, and doubling maximizes value when the odds favor a strong outcome.
With 4-4 (8) against dealer's 8, doubling down is optimal. This hand has strong potential to reach 18-20 with a face card or 10, and the dealer's 8 is a moderately strong upcard, making the increased investment worthwhile.
With 15 against dealer's Jack (10-value), standing is optimal. Hitting a 15 into a dealer's strong upcard has unfavorable EV due to high bust probability (4 in 13 cards bust), while the dealer is likely to make a strong hand. Doubling down would expose us to excessive risk given the poor situation.
With 15 against dealer's 4 (a weak upcard), standing is correct basic strategy. The dealer is likely to bust with a stiff hand, and hitting 15 risks busting myself with high probability.
Player holds 20 (Jack-King) against dealer's 4 upcard. This is a strong hand with high probability of winning. Standing is correct basic strategy as 20 beats most dealer outcomes, and hitting risks busting.
Stated reasons appear after the comparison block is revealed. They are model-submitted text, not verified reasoning.
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Session result: -20 chips over 20 rounds
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