if you know your first card before you bet

[Meistro]

What are the various advantages for first card knowledge? Ace = 53%, 10 = 10%? 9 = 1.5%?

What if you know your card and the dealers card, for example you have an 8, dealer has a 5.

An 8 (for you) is neutral and anything else is a disadvantage? How severe is the disadvantage of having a five as your first card.

 

[Sucker]

If your first card is a ten your advantage is 13%, not 10%. If it's a nine, it's closer to 0.5%. Eight is about -1%. If your 1st card is a 5, it's about -16%.

 

[Meistro]

Thank you. What impact does TC have on this? For example, is a 9 at TC -1 a negative expectation bet? I would imagine not.

 

[shadroch]

What about if you know the dealers first card before you bet?

 

[Pro21]

If your first card is a ten your advantage is 13%, not 10%. If it's a nine, it's closer to 0.5%. Eight is about -1%. If your 1st card is a 5, it's about -16%.

Of course this varies based on number of decks and rules. A 5 is closer to -20%. All these numbers are in the book as well as expectations for any dealer up card for 1,2,6,8 decks with various rules.

 

[pomkon]

If your first card is a ten your advantage is 13%, not 10%. If it's a nine, it's closer to 0.5%. Eight is about -1%. If your 1st card is a 5, it's about -16%.

how do you work them out?

 

[matt21]

Of course this varies based on number of decks and rules. A 5 is closer to -20%. All these numbers are in the book as well as expectations for any dealer up card for 1,2,6,8 decks with various rules.

bump.

pro21, which book are you referring to? ExCAA? I just skimmed through half a dozen books laid out in front of me, but couldn't find it.

I am looking for these percentages right now.

I found the info for the player's advantage/disadvantage based on the dealer's up card on (Dead link: http://www.blackjacktactics.com/blackjack/odds/). As you say, this would vary to some extent based on number of decks and rules.

But am having trouble finding the player adv/disadv for a given upcard for the player.

Thanks in advance,
Matt21

 

[KenSmith]

You could figure these numbers using the expected value charts at bjmath.com

 

[QFIT]

For advantage knowing the first card for varioius TCs, see Modern Blackjack page 435. You can enlarge the chart by clicking on the link below it.

 

[matt21]

Wow those are quick replies!

You could figure these numbers using the expected value charts at bjmath.com

Ok I had a look at those tables. I copied them into a spreadsheet and then did the following:

1. I checked the probability added to 100% - that was fine.
2. Determined the optimal strategy for each combination by taking the maximum value out of the hit/stand/double/split columns.
3. I then multiplied the optimal by the probability of the combination occuring into column 'A'
4. When summing column 'A' I came up with a figure of 0.037553 - a positive figure. I would ahve thought that figure would be -0.005% - say for a typical BJ shoe game.

Have I done something wrong in my calculation?

That said, I can see how I could then read the advantage/disadvantage given the dealer's upcard from this spreadsheet.

How about determining the advantage based on the player's upcard?

For advantage knowing the first card for varioius TCs, see Modern Blackjack page 435. You can enlarge the chart by clicking on the link below it.

Hi QFIT, yes I have looked at your chart already - however I wanted to try and get numbers as accurate as possible. Though your chart will definitely a starting point, so I will have a look at that.

Thanks guys!

 

[k_c]

bump.

pro21, which book are you referring to? ExCAA? I just skimmed through half a dozen books laid out in front of me, but couldn't find it.

I am looking for these percentages right now.

I found the info for the player's advantage/disadvantage based on the dealer's up card on (Dead link: http://www.blackjacktactics.com/blackjack/odds/). As you say, this would vary to some extent based on number of decks and rules.

But am having trouble finding the player adv/disadv for a given upcard for the player.

Thanks in advance,
Matt21

You can get composition dependent EVs from the program on my website.

Input one card for player and click compute.

You can vary number of decks and rules. Also you can vary shoe composition if you wish. Link is below.

Compute exact blackjack expected values

 

[WRX]

Read the appendix, matt21.

 

[matt21]

many thanks everyone!

for reference (ExCAA, Appendix D):
Basic Strategy Edge with given upcard (for dealer) - p566
Basic Strategy Edge with given upcard (for player) - p569

Matt21