Would 9vs7 be a BS, play if............

jack.jackson

Well-Known Member
......doubling on Three cards were allowed? I mean, would it therefore be a DD, BS play? Also wouldnt this rule affect all hands for doubling on 8 and 9 and Soft-hands as well?
 
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rollem411

Well-Known Member
I don't get how a 3 card hand of 9 vs 7 would benefit you any more than a 2 card hand of 9 vs 7. I think the advantage is when you get 3 cards where it's a BS DD or even an index play DD, not straying from BS. So if you were to get a 9 vs 4, in 3 cards, thats where the advantage comes in..Unless I'm missing something.
 

jack.jackson

Well-Known Member
Thanks roll-em

rollem411 said:
I don't get how a 3 card hand of 9 vs 7 would benefit you any more than a 2 card hand of 9 vs 7. I think the advantage is when you get 3 cards where it's a BS DD or even an index play DD, not straying from BS. So if you were to get a 9 vs 4, in 3 cards, thats where the advantage comes in..Unless I'm missing something.
Okay wait a minute. Maybe I'm getting this confused with Re-doubling? I think this is the confusion of my Question.

Please allow me to re-phrase the Question.

Would 9 vs. 7 be BS, DD, play if Re-doubling were allowed?
 

rollem411

Well-Known Member
jack said:
Okay wait a minute. Maybe I'm getting this confused with Re-doubling? I think this is the confusion of my Question.

Please allow me to re-phrase the Question.

Would 9 vs. 7 be BS, DD, play if Re-doubling were allowed?
Ok, that makes a lot more sense now. I've actually never heard of such a rule. But my take on it would be that the 9 vs 7 still wouldn't be a BS move because the chance of you getting an ace or a 2 to get the redouble would not be good. Also, you rarely ever double A,9, maybe against a 6, so your really only looking for that 2 against the 7.

Maybe for other hands, like a 5 vs 6 or something like that would be good. I don't even want to get into the soft hands without a computer to analyze this, ha.
 

EasyRhino

Well-Known Member
Huh. doubling 9v7 is fairly close anyway. I mean, it's part of the illustrious 18 index plays. So allowing redoubling might just be enough to put it over the top in case you get a deuce.

But I dunno for sure. I was kind of hoping Wong's Professional Blackjack might have it listed. It does not.
 

Kasi

Well-Known Member
jack said:
......doubling on Three cards were allowed? I mean, would it therefore be a DD, BS play?
I have no idea lol - that's a job for k_c!

But the index number is +3 so maybe it would be a BS play since the number would be met (like with 234 or 252 kind of thing anyway maybe? lol).
 

k_c

Well-Known Member
Kasi said:
I have no idea lol - that's a job for k_c!

But the index number is +3 so maybe it would be a BS play since the number would be met (like with 234 or 252 kind of thing anyway maybe? lol).
My program doesn't accomodate Spanish 21 rules but it's not too hard to compute redouble by hand using the program output.

5-4 vs 7 standard single deck

1. Basic:
hit: +20.13%
double: +19.05%

2. 5-4-2 vs 7 (probability = 4/49) [This is the only case there's a difference between doubling and redoubling]
EV if doubled = stand EV = -46.76% * 2 * 4/49 = -7.63%
EV if redoubled = hit EV (draw 1 card <> set HSN=12) = +28.77% * 4 * 4/49 = +9.39%

3. double EV if redouble is allowed = (difference between doubling and redoubling)
= 19.05% - (-7.63%) + 9.39% = +36.07%, which is greater than +20.13%

I'm sure it would be right to double 6-3 and 7-2 as well so it would be right to double any hard 9. This is for a standard single deck and not a Spanish 21 deck.

I think this is right. Instead of having to accept a total of hard 11 on a doubled bet you would be allowed to bet 4 times your initial bet on a hard 11, if I understand the rule correctly.

k_c
 
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