obbo

Here in Australia we have what is called "OBBO" which is dealer BJ only takes original and busted bets only. My question is supposing you split a pair of 8s and on the split hand you end up with a total of 16 vs dealer Ace. Now there is roughly a 33% chance of the dealer having bj. If you hit you will probably bust and lose the bet but if you stand and the dealer has bj then you dont lose the bet. It seems to me that in a marginal situation like this, it is better to stand when a split hand totals 16 vs dealer ace. Anyone know for sure?

If you hit you will probably bust and lose the bet but if you stand and the dealer has bj then you dont lose the bet. It seems to me that in a marginal situation like this, it is better to stand when a split hand totals 16 vs dealer ace. Anyone know for sure?

Using Cacarulo's expected value charts from www.bjmath.com, I come up with the following:

For S17, if you hit, your EV = -0.51. If you stand, you have approximately 4/13 of being bailed out by a dealer BJ and 9/13 of no dealer BJ. Your EV would be: 9/13 * -0.66 = -0.46.

For H17, the EVs are -0.54 and -0.41.

So you are better off standing!

For S17, stand on 15 and 16. For H17, also stand on 13 and 14.

For S17, stand on 15 and 16. For H17, also stand on 13 and 14.

For hitting, I was using the EV as posted in the charts, without taking a dealer BJ into account. The reduces the EV for hitting somewhat. So the revised strategy is: for S17, stand on 14-16 and for H17, stand on 12-16, with hitting or standing on 12 being a toss up.

for obbo the correct play is split 8,8 agiainst the dealer's 10

cheesrs

buccaneer

In general, it is better to stand on 3 or more card 16's vs 10. This includes post split hands and this would be even more true for OBBO. buccaneer is also correct that you should split 8,8 vs 10 in addition to A,A vs 10 for any number of decks. On every site I've seen, the strategy is incorrectly listed as not splitting 8,8 vs 10.

However you asked specifically about 8,8 vs Ace. This hand in general should not be split by the basic strategy player for any number of decks, NDAS or DAS. You should still split A,A. If you did split however, then you are correct. The EV's for 8,8 vs Ace, 6D NDAS SPL1 are:

Hit post-split 16 vs Ace: -0.709292321979804
Stand post-split 16 vs Ace: -0.705069523852757

The same should hold for SPL2-3 as well. Good observation.

As far as Panama Rick's comments are concerned - just ignore them (sorry Panama but I have no idea what you're talking about and it's just very wrong). The non-split strategy is exactly the same for OBBO as it is for American rules since you are not placing any more bets on the table and you shouldn't be doubling if you can bust. In other words, you lose exactly the same amount to a dealer BJ whether or not you bust a non-split hand - 1 unit, and p(BJ) is the same whether you hit or stand for American rules and OBBO.

Sincerely,
MGP

The Australian rule is worse than OBBO according to CVData which calls this rule BB+1. There is no dealer hole card and if the dealer gets blackjack the player loses bust bets plus one other if any remain, i.e. if the original bet busts the player will lose one of any remaining bets which would not be lost with OBBO.

The Australian rule is worse than OBBO according to CVData which calls this rule BB+1. There is no dealer hole card and if the dealer gets blackjack the player loses bust bets plus one other if any remain, i.e. if the original bet busts the player will lose one of any remaining bets (which would not be lost with OBBO).

The Australian rule is worse than OBBO according to CVData which calls this rule BB+1. There is no dealer hole card and if the dealer gets blackjack the player loses bust bets plus one other if any remain, i.e. if the original bet busts the player will lose one of any remaining bets which would not be lost with OBBO.

I don't know of any other country but Australia that uses OBBO. Dealer BJ takes the original bet and any busted bets. If the original bet busts and no other split hands bust then only the original bet is lost. I think your information is not correct.

Hi again,

Your response is interesting because I asked awhile back on advantageplayer whether it was literal OBBO or BBO (busted bets plus 1) and someone replied with a lot of confidence that it was all busted bets and then if any are left one more - whether or not it was the bet in the first spot (the literal original bet). (I like the term BBO because it's consistent with OBO - Cacarulo coined the term BB+1 and that's the one Norm likes)

I've never been to Australia, but the distinction is important because if you only lose the literal original bet, and not any bet remaining after busting, then the strategy is to split 8,8 vs Ace in addition to 8,8 vs 10 and A,A vs all for any number of decks DAS/NDAS.

Furthermore, in this case then it is better to hit split 16's vs Ace - the ev's for 6D Literal OBBO NDAS NS are:

Hit 16 vs Ace post-split: -0.652050945812682
Stand 16 vs Ace post-split: -0.652266829175659

I've never been to Australia, and I don't know if you're from Australia or not but the poster on ap lives there and goes to several casinoes.

Does anyone know with 100% certainty whether it's literally OBBO or BBO?

Sincerely,
MGP

In Australia all games are DAS and we have three different variations for dealer action on a bj;

OBO (all Queenland casinos) which is Original Bets Only i.e exactly same as hole card rule.

OBBO which stands for Original and Busted Bets Only but "original" does not imply the literal original bet, it means that if the dealer has a BJ they will take one bet from whatever is remaining. In this situation it is correct to split 8's vs 2-10 only, then against a 10, for the first split 8, bs is to stand on 15 or higher and to do so with other split 8's, so long as one of the split 8's already played remains unbusted. Split A's vs all.

ENCH which stands for European No Hole Card Rule - split A's vs 2-10, split 8's vs 2-9.

I was basing my calculations on one hand being protected from losing to a BJ. Apparently, either hand could lose to a BJ.

Thank you for verifying that. The name is just too confusing and should be changed to either BBO or BB+1.

Ok - checked strategies of standing post split on various numbers vs 10 and get the following:

8,8 vs 10 OBBO DOA DAS NS SPL3 6D

Stand 17 vs 10: -0.546399814572616
Stand 16 vs 10: -0.54308172745257
Stand 15 vs 10: -0.542093530695434
Stand 14 vs 10: -0.549532760206027

I can't change the strategy though based on a given number of busted hands - that would be unecessarily difficult to program into my ca.

As you suggested, standing on 15 vs 10 post-split to 8,8 vs 10 yields the best EV, even not taking into account the presence of unbusted hands. To me this means it would always be better to stand post-8,8 vs 10 split on 15 vs 10. SPL3 was better than SPL1 in all cases so you should also always resplit.

I'm curious how you came up with that strategy if you don't mind me asking?

Thanks,
MGP

levi civita has hit the nail on the head ! right on mate !!

buccaneer