Should you double 9 against a 7?
Hit. The book doubles 9 against a 3 through 6 and hits against the rest.
Why
Against a 7 the dealer ends on 17 or better 73.8% of the time, and on 19 or better 23.1%.
Doubling locks you into one card for twice the bet, and from 9 only 5 of the 13 ranks reach 19 or better. Take a card and keep your choices open. The book doubles 9 against a 3 through 6.
When the answer changes
This one doesn't change. Every rule set the chart covers hits 9 against a 7: one, two, six or eight decks, the dealer hitting or standing on soft 17, with or without double after split and surrender.
The full basic strategy chart for six decks, dealer hits soft 17, with every other rule set a tap away.
Questions
Should you double 9 against a 6?
Yes. Against a 6 the book doubles 9. A dealer showing a 6 goes over 21 43.9% of the time.
Is it different at a single-deck table?
No. At the app's table with a single deck, the book still hits. So does every rule set the chart covers.
More hands
- Should you double 9 against a 3?
- Should you double 8 against a 6?
- Should you double 9 against a 2?
- Should you double 10 against a 10?
- Should you hit 16 against a 7?
- Blackjack hands, one at a time
Guides
Know the book before you sit down.
