Indices for DAS vs No DAS

[bjcount]

My local stores all have DAS so I have not used nor have I studied any NDAS indices. After running a slew of index generating sims using my playing strategy, RPC, I noticed an extreme disparity in the indices for DAS vs NDAS.

I then went and reviewed the other playing strategy indices included with CVData. There again the same large spread in indices between DAS and NDAS.

For example 2,2 vs 2
for DAS split TC>= -3
for NDAS split TC>= +7

So now my question, why if it is ok to split at -3 because you can DD
and why then would you need +7 if you can't double down?

It seems to me that this would be a defensive play in either game, but having a 2 vs 2 with No doubling would be a better hand then hitting with a 4 (2+2) vs 2.

This happens on many indices such as 2,2 vs 3, 3,3vs 2, etc.
With 4,4 vs 4,5, or 6 it's only a hit with NDAS and there are indices to split in DAS.

I am sure I read the explanation in my library of BJ books, but I just can't recall where.

BJC

[Renzey]

Originally Posted by bjcount

I notice an extreme disparity in the indices for DAS vs NDAS.

For example 2,2 vs 2 w/ RPC:
for DAS split TC>= -3
for NDAS split TC>= +7

If it is ok to split at -3 because you can DD, why would you need +7 if you can't double down? It seems to me that this would be a defensive play in either game.

With 4,4 vs 4,5, or 6 it's only a hit with NDAS and there are indices to split in DAS.

BJC

It's simply that the extra gain from being able to double your action those times that you catch a card which creates a good doubling hand makes splitting a more efficient choice than hitting with some pairs.

Having 4/4 vs. 6 is a perfect example. Why in the world would you want to trade a mediocre total of 8 in for two lousy totals of 4 each? Because if you catch a 5, 6, 7 or Ace on either 4 (and you will 52% of the time), you've got a profitable double down! That added value with DAS makes 4/4 vs. 6 a proper double with a neutral count.

With 2/2 vs. 2, you're playing defensively whether you hit or split. But with DAS, splitting is less negative than hitting (-.083 EV). With NDAS, just hitting is less negative (-.115 EV). Whereas splitting with NDAS would be -.148 EV (all at a neutral count). As the TC rises, some hands become less negative to split even with NDAS. Similar consequences apply with 2/2 vs 3, with 3/3 vs. 2 or 3, and with 6/6 vs. 2.

[bjcount]

Originally Posted by Renzey

It's simply that the extra gain from being able to double your action those times that you catch a card which creates a good doubling hand makes splitting a more efficient choice than hitting with some pairs.

Having 4/4 vs. 6 is a perfect example. Why in the world would you want to trade a mediocre total of 8 in for two lousy totals of 4 each? Because if you catch a 5, 6, 7 or Ace on either 4 (and you will 52% of the time), you've got a profitable double down! That added value with DAS makes 4/4 vs. 6 a proper double with a neutral count.

With 2/2 vs. 2, you're playing defensively whether you hit or split. But with DAS, splitting is less negative than hitting (-.083 EV). With NDAS, just hitting is less negative (-.115 EV). Whereas splitting with NDAS would be -.148 EV (all at a neutral count). As the TC rises, some hands become less negative to split even with NDAS. Similar consequences apply with 2/2 vs 3, with 3/3 vs. 2 or 3, and with 6/6 vs. 2.

Renzey, thank you for the explanation.

BJC

[Automatic Monkey]

Originally Posted by bjcount

My local stores all have DAS so I have not used nor have I studied any NDAS indices. After running a slew of index generating sims using my playing strategy, RPC, I noticed an extreme disparity in the indices for DAS vs NDAS.

I then went and reviewed the other playing strategy indices included with CVData. There again the same large spread in indices between DAS and NDAS.

For example 2,2 vs 2
for DAS split TC>= -3
for NDAS split TC>= +7

So now my question, why if it is ok to split at -3 because you can DD
and why then would you need +7 if you can't double down?

It seems to me that this would be a defensive play in either game, but having a 2 vs 2 with No doubling would be a better hand then hitting with a 4 (2+2) vs 2.

This happens on many indices such as 2,2 vs 3, 3,3vs 2, etc.
With 4,4 vs 4,5, or 6 it's only a hit with NDAS and there are indices to split in DAS.

I am sure I read the explanation in my library of BJ books, but I just can't recall where.

BJC

To put it all in perspective, yes the split strategy and indices for DAS vs. not are going to be very different. But those indices aren't worth very much. The only split indices with a significant cash value are XX vs. 5 and 6, and obviously those are going to be the same whether or not you can DAS.

[Kasi]

Originally Posted by bjcount

This happens on many indices such as 2,2 vs 3, 3,3vs 2, etc....

I don't know bjcount - basically maybe because BS is to basically hit those hands with NDAS and split them with DAS.

So the departure from BS would be to just hit them in DAS at -3 rather than split. And the departure from BS with NDAS would be to split them at +7 rather than hit.

At least that's why one is negative and one is positive while the number means the same thing - "split at that number or more".

Not a good explanation I'm sure lol.

Why are they what they are - because CVDATA said so lol.

Ours is not to reason why
Just apply. lmao.

My rhyming pales in comparison to our resident poetry laureate - The Wise One lol.

[Blue Efficacy]

The ability to double down strengthens your defenses in these defensive splits.

Think about it, you win one doubled hand, that covers the loss for the other half of the split which might have been a stiff. With DAS you can win one half of your split and have a net profit for the round. With no DAS you cannot do that.

[bjcount]

Originally Posted by Blue Efficacy

The ability to double down strengthens your defenses in these defensive splits.

Think about it, you win one doubled hand, that covers the loss for the other half of the split which might have been a stiff. With DAS you can win one half of your split and have a net profit for the round. With no DAS you cannot do that.

Thanks to all for the replies.

The concept of why we make the appropriate play I understand, but that does not explain (other than Renzey's reply) the huge disparity in the indices from DAS vs NDAS.

If your going to put out more money to make the split, than even in a NDAS game you have the same potential for a push. If it's a defensive play and the chances of improving your hand is 52% than the chances of improving your hand is still the same whether it's DAS or NDAS (at neutral count).

Would it be that in NDAS, say if you have a 3,3 vs 2 and the index to split is +7, you are relying on the dealer to bust since the shoe is heavy in high cards? In the DAS where the index is -3, you are putting out more money in the chances (now is it < or > 52%?) that you will improve your hands and have the chance for a DD. Now your putting more money out in a negative situation. If you do it in a negative situation for DAS, than how much different is NDAS going to be for the same hand?

Renzey's math example probably spells out the answer best.

BJC

[FLASH1296]

The Dealer's Bust Probability contributes relatively little to the +7 play.

Off the top the Dealer busts a bit over 28% of the time on average.
With a (Level One) +7 True Count I suspect that the dealer's bust %
will rise to close to 30%

Contrary to our intuitive (but thoroughly incorrect) reasoning,
the Dealer's overall bust % does not move very much in
accordance with a changing True Count.

[chichow]

to the OP

It would help to know what kinda of count you are using in order to better answer your questions....

[Blue Efficacy]

DAS gives you more potential gain by making the split at neutral counts, that's why the indexes are much lower.