Blackjack · 20 rounds · Sep 25, 2026, 8:38 PM UTC
Round 20
Dealer
Round 20 result · Dealer 17
Claude Haiku 4.5
Hand 1 · 16 soft · bet 10
Loss -20
With a hard 17 against dealer's 8, standing is optimal. Doubling risks busting or getting a worse outcome, while the dealer has a high bust probability from 8 with dealer_hits_soft_17=false.
With 15 against dealer's Jack (10-value), standing is the correct play. Hitting risks busting (any card 7+ busts), while the dealer must play by fixed rules and has a strong upcard. Basic strategy recommends standing here.
I have 20 (K-K), which is an excellent hand. The dealer shows a 3, which is a weak upcard. Standing maximizes my winning probability against this dealer position.
With a hard 12 against dealer's 3, standing is optimal. The dealer's weak upcard (3) means a high bust probability on dealer's next draw, and hitting my 12 risks busting immediately (any card 10+ busts me). Basic strategy calls for standing here.
With a hard 12 against dealer's 8, hitting carries high bust risk (40.8% with 10-value cards). Standing at 12 vs 8 is the standard basic strategy play—the dealer's 8 is moderately strong but not dominant enough to warrant the bust risk of hitting.
With a hard 17 against dealer's King (10-value), standing is optimal. The dealer showing 10 has a strong hand, and hitting risks busting (any card 5 or higher busts). Basic strategy dictates standing on hard 17 versus any dealer upcard.
With a hard 10 against the dealer's Jack (10-value card), doubling down is the optimal play. A hard 10 is a strong position where hitting for one more card has high probability of improving the hand, and doubling allows us to capitalize on this advantage while the dealer shows a moderately strong upcard.
With Ace-Ace against dealer's Ace (which could be blackjack), splitting maximizes value by creating two independent hands with strong starting positions. Split aces each get one card, giving two chances to reach 21. Standing on 12 is weak, and hitting risks busting.
Hard 17 against dealer's 7 is a stand. Dealer hits soft 17, so dealer has a reasonable chance to bust or make 18-21. Hitting risks busting immediately (any card 5+), while standing gives us a decent chance to win if dealer busts.
With a pair of 3s totaling 6 against dealer's 5 (a weak upcard), splitting gives two chances to build strong hands. The dealer's bust probability is high, so maximizing hands in play is profitable. Doubling a stiff 6 is too risky.
With 9 against dealer's 5 (weak upcard), doubling down is optimal basic strategy. The dealer likely busts from 5, and doubling maximizes expected value in this favorable situation.
With 13 against dealer's 5 (a weak upcard), hitting is the optimal play. The dealer is likely to bust, but my hand needs improvement. Basic strategy dictates hitting 13 against dealer 5.
Hand 1 has 18 against dealer's 5 (weak upcard). Dealer busts frequently from 5, so standing on 18 is correct basic strategy. Hand 0 already completed with 19.
With 14 against dealer's 7, hitting is the optimal play. The dealer shows a strong upcard (7), and my 14 is too weak to stand. Basic strategy dictates hitting in this spot to improve the hand, as the risk of bust is manageable and necessary given the dealer's strength.
With a hard 17 against dealer's 7, standing is the mathematically optimal play. The dealer has a decent upcard but 17 is a strong hand that wins in many scenarios, and hitting risks busting with a 40% probability of drawing a card that would break the hand.
With 16 against dealer's 6 (weak upcard), standing is optimal. The dealer has a high bust probability from 6, and hitting 16 risks busting immediately while giving up the chance dealer busts first.
With a hard 8 against dealer's 2 (a weak upcard), doubling down is the mathematically optimal play. The dealer's 2 is vulnerable, and doubling maximizes expected value by betting more when the dealer is likely to bust or reach a weak total.
With a hard 7 against dealer's 7, hitting is correct. A 7 is very weak and I need to improve my hand significantly to compete. The dealer's 7 is a moderate card, so improving my total is more important than doubling down with such a poor starting hand.
I have a soft 18 (Ace-5-2) against dealer's 7. Soft 18 vs 7 is a stand according to basic strategy; hitting risks busting or getting worse hands while standing has good winning probability.
With 13 against dealer's 9, hitting is standard basic strategy. The dealer's 9 is strong, and standing on 13 loses most of the time. Doubling would risk more chips for a hand that's still weak after doubling.
Hard 17 against dealer 9 is a borderline spot, but standing is the mathematically correct play. Hitting a hard 17 has negative expected value since we'll bust frequently (4-card ranks bust us) while dealer 9 doesn't guarantee a win even if we improve.
With a hard 7 against dealer's Jack (10-value), hitting is the correct basic strategy play. The probability of improving without busting is very high, and standing would put me in a losing position.
I have a soft 18 (Ace-3-4) against dealer's Jack. Soft 18 stands against all dealer upcards in basic strategy; hitting risks busting while standing gives a strong hand that wins or pushes against most dealer outcomes.
With a hard 11 against dealer's 8, doubling down is optimal. My 11 has strong potential to reach 21 with any ten-value card, and the dealer's 8 is moderately strong but beatable. Doubling maximizes value in this favorable situation.
With a hard 8 against dealer's Jack (10-value), hitting is the optimal play. The hand is too weak to stand or double; I need to improve significantly to win this hand.
I hold a soft 19 (Ace-6-2) against dealer's Jack upcard. Standing is optimal as hitting risks busting or achieving no improvement, while the current hand beats most dealer outcomes except 20 or blackjack.
With A-2 (soft 13) against dealer's 6 (a bust card), doubling down is optimal. The dealer is likely to bust, and doubling maximizes expected value when holding a soft hand against a weak upcard.
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Session result: +30 chips over 20 rounds
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