Splitting 8's and surrendering 17???
December 22nd, 2009 at 1:26:53 AM
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Dear Wizard:
I don't know that this has been addressed in previous threads but I wanted to ask a few simple questions regarding blackjack strategy:
Depending on the number of decks in play as well as wether or not the dealer hits/stays on soft 17, I've noticed variations between:
1) wether or not to split 8's against a dealer 10 and
2) whether or not to surrender hard 17 against a dealer A
That leads me to ask the following question...
How much of a difference will this make in overall expected return for both of these scenarios?
I'm certain that I'm not the only one who gets a little uncomfortable feeling everytime two 8's are dealt and the dealer is showing a 10 up. Everyone likes to say "always split aces and eights." I've started to surrender two eights against dealer ten regardless of the number of decks used as well as whether or not the dealer stays/hits soft 17.
Conversely, I find it rather difficult to surrender a 17 against a dealer A as suggested in some charts depending on the decks and dealer action.
Any thoughts and comments would be appreciated.
I don't know that this has been addressed in previous threads but I wanted to ask a few simple questions regarding blackjack strategy:
Depending on the number of decks in play as well as wether or not the dealer hits/stays on soft 17, I've noticed variations between:
1) wether or not to split 8's against a dealer 10 and
2) whether or not to surrender hard 17 against a dealer A
That leads me to ask the following question...
How much of a difference will this make in overall expected return for both of these scenarios?
I'm certain that I'm not the only one who gets a little uncomfortable feeling everytime two 8's are dealt and the dealer is showing a 10 up. Everyone likes to say "always split aces and eights." I've started to surrender two eights against dealer ten regardless of the number of decks used as well as whether or not the dealer stays/hits soft 17.
Conversely, I find it rather difficult to surrender a 17 against a dealer A as suggested in some charts depending on the decks and dealer action.
Any thoughts and comments would be appreciated.
December 22nd, 2009 at 6:47:45 AM
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The always split 8's is based not so much on a particular good value to the player to have an 8 but on the bad value to the player of having 16. The dealer's most probable hand totals 20 which is a sure loss for a player holding 16. Even if the dealer has a lower hole card and must draw an additional card its still more likely for the dealer to win. So I agree with the Split 8's always rule. Besides, its easy to remember and won't occasion any annoying comments from fellow players.
December 22nd, 2009 at 7:09:36 AM
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The Wizard's Blackjack Appendix 9 (https://wizardofodds.com/blackjack/appendix9.html) contains a list of all of the composite probabilities. He's calculated the expected value of all plays based on your first two cards and the dealer's up card. From that, you can create all of the strategy charts.
For example, in a 6 deck game where the dealer stands on soft 17 and you have 17 (a 10-7) against an "A", the expected value of standing is -.476308 units.
In a six deck game where the dealer hits on soft 17, the expected value of standing on a 10-7 is -.513758 units. Surrendering is an expected value of -0.5 units.
So if you decide to stand on a 10-7 against a dealer A in 6 deck blackjack and the dealer hits on a soft 17, you will lose on average .013758 units vs surrendering.
Similarly if you decide to surrender a 10-7 against a dealer A in 6 deck BJ and the dealer stands on all 17s, you will lose on average .023692 units vs standing.
For example, in a 6 deck game where the dealer stands on soft 17 and you have 17 (a 10-7) against an "A", the expected value of standing is -.476308 units.
In a six deck game where the dealer hits on soft 17, the expected value of standing on a 10-7 is -.513758 units. Surrendering is an expected value of -0.5 units.
So if you decide to stand on a 10-7 against a dealer A in 6 deck blackjack and the dealer hits on a soft 17, you will lose on average .013758 units vs surrendering.
Similarly if you decide to surrender a 10-7 against a dealer A in 6 deck BJ and the dealer stands on all 17s, you will lose on average .023692 units vs standing.
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You want the truth! You can't handle the truth!
December 22nd, 2009 at 7:30:32 AM
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Quote: FleaStiffThe always split 8's is based not so much on a particular good value to the player to have an 8 but on the bad value to the player of having 16. The dealer's most probable hand totals 20 which is a sure loss for a player holding 16. Even if the dealer has a lower hole card and must draw an additional card its still more likely for the dealer to win. So I agree with the Split 8's always rule. Besides, its easy to remember and won't occasion any annoying comments from fellow players.
Not exactly. Splitting 8-s against an A where the dealer can hit on soft 17 has an expected value of -.514318 units (on 6 decks). Surrending has an expected value of -.5 units. Surrendering is the better play. Standing is worse. It is exactly these situations and plays like it where you can shave a a few points off of your house edge.
The same people who yell at you for making the play above will stand on 16 against a 7, not hit a 12 on a 2, won't double their soft 18s, and so on. If someone is rude to me, then I will be as rude to them when they eventually make that dumb play (and I will be especially caustic if their play caused the dealer to make a hand or for them to lose). If someone says nothing to me about my play, then I don't say anything to them about theirs.
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You want the truth! You can't handle the truth!
December 22nd, 2009 at 8:01:19 AM
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Quote: boymimboQuote: FleaStiff
The same people who yell at you for making the play above will stand on 16 against a 7, not hit a 12 on a 2, won't double their soft 18s, and so on. If someone is rude to me, then I will be as rude to them when they eventually make that dumb play (and I will be especially caustic if their play caused the dealer to make a hand or for them to lose). If someone says nothing to me about my play, then I don't say anything to them about theirs.
I think better than to make a comment about their play would be to make a comment that makes it look like you don't care what their opinion is and at the same time gives a slight "slap" so they know not to do it again.
EXAMPLES:
"What are you doing, don't you know you should always split 8-8 (or whatetver play?"
"Well, they said I shouldn't have bought that empty lot in the bad part of town. Now it is a ballpark and I can lose $20 for each car you see parked each game so I don't care."
"I'm doing research on my book. This chapter is on how long you can play "wrong" before the person giving advice leaves the table."
Can we come up with a few? Surely I'm not the only one whose workday is slow for the holiday.All animals are equal, but some are more equal than others
December 22nd, 2009 at 8:52:07 AM
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The numbers cited from Blackjack appendix 9 are helpful here and what you should look to. As a general comment, situations where plays differ among strategy charts are usually borderline hands. That being said, you will never be sacrificing a huge amount by playing these wrong. Deciding to surrender 88 vs 10 will get you lower variance at the expense of a slight increase in house edge. Certainly okay if you wish to do this.
Its also worth noting how borderline some plays are in blackjack. In particular, 16 vs 10 in a non-surrender game is so borderline that I often tell people to do whatever they want on it when they ask for advice. Whether they stand or hit matters very little. Also, 12 vs 4 is very close to being a hit. Doing so drives the other people at the table crazy and can be a fun activity if you like that kind of thing. Again you can take the alternate play here while sacrificing a miniscule amount on the house edge.
Interestingly, On these two hands, simply eyeballing the cards on a full table (rudimentary card counting) will actually give you a better indication of the proper play than sticking to total-dependent basic strategy. If there are more low cards than high cards on the table, stand. If there are more high cards than low cards, you hit. If (very) small decreases in house edge interest you but you do not wish to actually count cards, then this is a practice you can take up.
Its also worth noting how borderline some plays are in blackjack. In particular, 16 vs 10 in a non-surrender game is so borderline that I often tell people to do whatever they want on it when they ask for advice. Whether they stand or hit matters very little. Also, 12 vs 4 is very close to being a hit. Doing so drives the other people at the table crazy and can be a fun activity if you like that kind of thing. Again you can take the alternate play here while sacrificing a miniscule amount on the house edge.
Interestingly, On these two hands, simply eyeballing the cards on a full table (rudimentary card counting) will actually give you a better indication of the proper play than sticking to total-dependent basic strategy. If there are more low cards than high cards on the table, stand. If there are more high cards than low cards, you hit. If (very) small decreases in house edge interest you but you do not wish to actually count cards, then this is a practice you can take up.
January 14th, 2010 at 2:20:10 PM
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Generally the rules that change depending on numbers of decks and if you are allowed to double after you split have little or not impact on the expected value of the game.
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For example the general rule of hitting a hard 16 against a dealer 10 has such a narrow advantage that if there is one or two small cards out on the table, you are mathematically better off standing. The Wizard's appendix 9 allows you not only to know what is the proper move, but also lets you work out how big the advantage would be.
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Take a look at Wizard's Simple Strategy, which is a simplified set of rules for playing blackjack. The cost due to imperfect plays is only 0.14%, relative to liberal Vegas Strip rules. That is the cost of one hand for about every 12 hours of play. Compared to the 250 cells in the Basic Strategy, the Wizard's Strategy has only 21, as follows.
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For example the general rule of hitting a hard 16 against a dealer 10 has such a narrow advantage that if there is one or two small cards out on the table, you are mathematically better off standing. The Wizard's appendix 9 allows you not only to know what is the proper move, but also lets you work out how big the advantage would be.
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Take a look at Wizard's Simple Strategy, which is a simplified set of rules for playing blackjack. The cost due to imperfect plays is only 0.14%, relative to liberal Vegas Strip rules. That is the cost of one hand for about every 12 hours of play. Compared to the 250 cells in the Basic Strategy, the Wizard's Strategy has only 21, as follows.
