festerr: Splitting 8s v 10 adj. no. for OBBO rules

[festerr]

Gday all,

The HILO adjustment number for splitting 8s v 10 is +8. ie At TC of 8 or more, dont split, but stand.

Does anyone know what the adjustment number for 8s v 10 in OBBO rules is? In OBBO rules, the dealer only receives one card, therefore players' splits and doubles are carried out before we know if the dealer has a BJ. In this case, it is possible to split 8s v 10 and bust both hands - in this case you lose both bets.

Also the 99 v A adjustment number (normally +3) would be different too - does anyone know what it is for OBBO rules?

Cheers and merry xmas,

festerr

[Francis Salmon]

> The HILO adjustment number for splitting 8s v 10 is
> +8. ie At TC of 8 or more, dont split, but stand.
> Does anyone know what the adjustment number for 8s v
> 10 in OBBO rules is? In OBBO rules, the dealer only
> receives one card, therefore players' splits and
> doubles are carried out before we know if the dealer
> has a BJ. In this case, it is possible to split 8s v
> 10 and bust both hands - in this case you lose both
> bets.

I don't know the answer to your question but I think that another question has to be resolved first: What is the impact on basic strategy by this rule?
Under ENHC it's never good to split the eights neither against the ten nor against the ace but here I think you should still go ahead with the split and then try to avoid busting both hands.Either you play the first hand normally but once you have busted it, you should probably stand on 14 with the second hand.Better might be to stand on 15 with the first hand in case you have to hit another stiff on the second hand.
As I live at maximum distance from Australia,I never felt the urge to study the question but I'm sure Andrew Scott would know what to do here and he could probably even tell you a precise index.Unfortunately he hasn't been around for a while.

Francis Salmon

[MGP]

> I don't know the answer to your question but I think
> that another question has to be resolved first: What
> is the impact on basic strategy by this rule?
> Under ENHC it's never good to split the eights neither
> against the ten nor against the ace but here I think
> you should still go ahead with the split and then try
> to avoid busting both hands.Either you play the first
> hand normally but once you have busted it, you should
> probably stand on 14 with the second hand.Better might
> be to stand on 15 with the first hand in case you have
> to hit another stiff on the second hand.
> As I live at maximum distance from Australia,I never
> felt the urge to study the question but I'm sure
> Andrew Scott would know what to do here and he could
> probably even tell you a precise index.Unfortunately
> he hasn't been around for a while.

> Francis Salmon

We figured this out awhile ago on the BJMath site that's why OBBO was renamed to BBO or BB+1 (I like the former) since literally it is always the loss of any busted bets and then one more from any of the remaining bets. This is opposed to the literal meaniing of loss of the original bet in the first spot, plus any additional busted bets.

The summary of the BBO TD strategy for 8,8 vs 10/A is here:

http://www.bjmath.com/bin-cgi/bjcomputer.pl?read=2562

[festerr]

[festerr]

> We figured this out awhile ago on the BJMath site
> that's why OBBO was renamed to BBO or BB+1 (I like the
> former) since literally it is always the loss of any
> busted bets and then one more from any of the
> remaining bets. This is opposed to the literal
> meaniing of loss of the original bet in the first
> spot, plus any additional busted bets.

> The summary of the BBO TD strategy for 8,8 vs 10/A is
> here:

> http://www.bjmath.com/bin-cgi/bjcomputer.pl?read=2562

Hi MGP,

Another name that can be used for these rules is 1nbh - lose 1 unit of non-busted hands. I looked through all those bjmath posts and was really surprised to see that one should not split 88vA.

festerr

[Francis Salmon]

I see you went to quite some lenght in analysing the situation.Your conclusions are convincing but it seems to me that you failed to address one important point.
Suppose you split the eights against the ace and now you get a total of 16 on one of the hands.If you hit here you not only risk to bust this hand, you put also the other hand in jeopardy in case the dealer will make Blackjack.So I think that you should stand here thus saving some ev.Even on 15 you should stand and likewise against the 10.
Although I don't think that the gain in ev will be enough to reverse the decision 8/8v Ace, it would make it considerably closer.

Francis Salmon

[MGP]

[festerr]

> Actually we went to some length to analyze the
> algorithm to see if it calculated the split EV's
> correctly - which it does.

> The point you make below is an interesting and looking
> at it yielded an interesting finding.

> You are correct here that standing for post-split 8's
> vs 10 for totals of 15 and 16 you will get a better EV
> and that the difference is minimal.

> The 1D differences in EV for the game would be:
> Stand post-split 16 vs 10: 0.00056%
> Stand post-split 15,16 vs 10: 0.00064%

> The problem is that how you define your strategy. If
> you are willing to have a different post-split
> strategy change then yes the strategy is above. But
> this does not balance the pre-split strategy to change
> the overall TD strategy.

> Here you were close. If you are allowed SPL2 or SPL3
> then the strategy actually changes to Split for 1D if
> you even just stand on 16:

> 8,8 vs A 1D BBO Stand EV: -0.65983
> 8,8 vs A SPL3 EV: -0.666404
> Split EV standing on post-split 16 SPL1: -0.667778
> Split EV standing on post-split 16 SPL2: -0.65933
> Split EV standing on post-split 16 SPL3: -0.658777

> The actual 1D strategy however would be to stand on
> totals 13-16:

> Split EV standing on post-split 13-16 SPL1: -0.650906
> Split EV standing on post-split 13-16 SPL3: -0.639592

> Looking at 6D now:

> 8,8 vs 10 standing on 15,16 net Game EV Diff: 0.00076%

> 8,8 vs A is a little better with standing on
> post-split 15,16 but it doesn't bring it anywhere near
> enough to split:

> 8,8 vs A Stand 6D BBO EV: -0.66468
> 8,8 vs A SPL3: -0.693943
> 8,8 vs A Stand post-split 15,16 SPL3: -0.680915

> So to summarize, if you allow changing post-split TD
> strategy from the pre-split TD strategy, then we have
> the following: for BBO DOA DAS NS:

> 1D:
> Split 8,8 vs 10 and Stand on 15,16
> Split 8,8 vs A and Stand on 13,14,15,16

> 6D:
> Split 8,8 vs 10 and Stand on 15,16
> Stand 8,8 vs A

> Now I'd say we've analyzed the situation at some
> length Thanks for the interesting suggestion

> Sincerely,
> MGP

Hi MGP,

Thank you very much for the considerable amount of time you guys have put into this topic. I have a couple of questions for you:

1)I am a little confused by the terminology you use - SPL1, SPL2, SPL3. Is SPL1 split to just 2 hands, SPL2 split to 3 hands etc??

2) You state the strategy for 6d is:

> 6D:
> Split 8,8 vs 10 and Stand on 15,16
> Stand 8,8 vs A

Surely 8,8 v A you hit not stand if you dont split?

3) In Australia, these rules only exist for the 8 deck game and I fear I have been using the wrong strategy - I have been splitting 8's and A's against everything.

4) Could you possibly give me the following EVs for an 8 deck game (lose 1nbh - lose 1 unit of non-busted hands, split to 3 hands):

88v10 split and play normal BS

88v10 split and stand on 15,16

88v10 stand

88v10 hit

88vA split and play normal BS

88vA stand

88vA hit

Cheers,

festerr

[MGP]

> I see you went to quite some lenght in analysing the
> situation.

Actually we went to some length to analyze the algorithm to see if it calculated the split EV's correctly - which it does.

> Your conclusions are convincing but it seems
> to me that you failed to address one important point.

The point you make below is an interesting and looking at it yielded an interesting finding.

> Suppose you split the eights against the ace and now
> you get a total of 16 on one of the hands.If you hit
> here you not only risk to bust this hand, you put also
> the other hand in jeopardy in case the dealer will
> make Blackjack.So I think that you should stand here
> thus saving some ev.Even on 15 you should stand and
> likewise against the 10.

You are correct here that standing for post-split 8's vs 10 for totals of 15 and 16 you will get a better EV and that the difference is minimal.

The 1D differences in EV for the game would be:
Stand post-split 16 vs 10: 0.00056%
Stand post-split 15,16 vs 10: 0.00064%

The problem is that how you define your strategy. If you are willing to have a different post-split strategy change then yes the strategy is above. But this does not balance the pre-split strategy to change the overall TD strategy.

> Although I don't think that the gain in ev will be
> enough to reverse the decision 8/8v Ace, it would make
> it considerably closer.

Here you were close. If you are allowed SPL2 or SPL3 then the strategy actually changes to Split for 1D if you even just stand on 16:

8,8 vs A 1D BBO TD Hit EV: -0.65983
8,8 vs A SPL3 EV: -0.666404
Split EV standing on post-split 16 SPL1: -0.667778
Split EV standing on post-split 16 SPL2: -0.65933
Split EV standing on post-split 16 SPL3: -0.658777

The actual 1D strategy however would be to stand on totals 13-16:

Split EV standing on post-split 13-16 SPL1: -0.650906
Split EV standing on post-split 13-16 SPL3: -0.639592

Looking at 6D now:

8,8 vs 10 standing on post-split 15,16 net Game EV Diff: 0.00076%

8,8 vs A is a little better with standing on post-split 15,16 but it doesn't bring it anywhere near enough to split:

8,8 vs A TD Hit 6D BBO EV: -0.66468
8,8 vs A SPL3: -0.693943
8,8 vs A Stand post-split 15,16 SPL3: -0.680915

And for 8D by request:

8,8 vs 10 Stand EV: -0.57357
8,8 vs 10 Hit EV: -0.5724
8,8 vs 10 SPL2 Normal TD: -0.548915
8,8 vs 10 SPL2 and Stand on 15,16: -0.543827

8,8 vs A Stand EV: -0.76827
8,8 vs A Hit EV: -0.66494
8,8 vs A SPL2 Normal TD: -0.697586

So to summarize, if you allow changing post-split TD strategy from the pre-split TD strategy, then we have the following: for BBO DOA DAS NS:

1D:
Split 8,8 vs 10 and Stand on 15,16
Split 8,8 vs A and Stand on 13,14,15,16

6D:
Split 8,8 vs 10 and Stand on 15,16
Hit 8,8 vs A

8D:
Split 8,8 vs 10 and Stand on 15,16
Hit 8,8 vs A

Now I'd say we've analyzed the situation at some length Thanks for the interesting suggestion.

Sincerely,
MGP

[MGP]

> 1)I am a little confused by the terminology you use -
> SPL1, SPL2, SPL3. Is SPL1 split to just 2 hands, SPL2
> split to 3 hands etc??

Yes that is correct:
SPL0 = No Splits Allowed
SPL1 = 2 Hands Max
SPL2 = 3 Hands Max
SPL3 = 4 Hands Max

> 2) You state the strategy for 6d is:

> Surely 8,8 v A you hit not stand if you dont split?

Yep - sorry about that - I do that too often. I got caught up with all the standing on 15,16 and just perseverated - the values were the correct ones though.

> 3) In Australia, these rules only exist for the 8 deck
> game and I fear I have been using the wrong strategy -
> I have been splitting 8's and A's against everything.

Unfortunately you were wrong to split 8's vs A - you might have to try and win one extra hand to make up for the loss over the years

> 4) Could you possibly give me the following EVs for an
> 8 deck game (lose 1nbh - lose 1 unit of non-busted
> hands, split to 3 hands):

I corrected my post and put the values you asked for there.

Cheers.

[festerr]

Hi MGP,

Many thanks for your responses.

Do you know what the adjustment number for splitting 8s v 10 (dont split) would be for 1nbh rules. Im guessing it is quite low - in the range of about T3-T5.

Cheers,

festerr

[MGP]

> Many thanks for your responses.

You're welcome.

> Do you know what the adjustment number for splitting
> 8s v 10 (dont split) would be for 1nbh rules. Im
> guessing it is quite low - in the range of about
> T3-T5.

I'm sorry I don't because my CA doesn't deal with counting yet except for insurance.

Btw, I still prefer BBO to 1nbh because it's not 1-non-busted-hand, it's really 1-non-busted-hand-and-all-busted-hands.

BB+1 also makes sense but I'm stubborn and I guess using a a non-letter when all the other dealer check types (i.e. OBBO, ENHC, OBO) use only letters so I find BBO more consistent.

Sincerely,
MGP

[Magician]

> Btw, I still prefer BBO to 1nbh because it's not
> 1-non-busted-hand, it's really
> 1-non-busted-hand-and-all-busted-hands.

> BB+1 also makes sense but I'm stubborn and I guess
> using a a non-letter when all the other dealer check
> types (i.e. OBBO, ENHC, OBO) use only letters so I
> find BBO more consistent.

For consistency, I would suggest ANHC (Australian No Hole Card). Then we'd have:

ENHC (European No Hole Card) - no hole card taken, lose all bets to dealer BJ
ANHC (Australian No Hole Card) - no hole card taken, lose busted bets plus one additional bet to dealer BJ
NHC (No Hole Card) - no hole card taken, lose original bet only to dealer BJ
HC (Hole Card) - hole card taken, lose original bet only to dealer BJ

The trick is convincing people to use consistent terminology. :-)