HE on ENHC blackjackswitch?

Geoff Hall

Well-Known Member
#21
Geoff Hall said:
It's possible that in high counts you would 'switch' against a 6. I think there would be times in neutral counts that you may also 'switch'.

I know that in neutral counts you do not 'switch' away against a 10 or Ace if the 'Blackjack' is a guaranteed winner.

I've dug out the 'switch' tables to see if guaranteeing a pay on 'Blackjack' will affect the 'switch'. Haven't looked yet but will post a short series of results from the simulated table in due course.
Ok, haven't got much time so I've just looked at the hands 10,6 and A,10 being dealt to the player and the 'switch' is identical for both 'Blackjack' guaranteed payout and not.

With the hands above, you should 'not switch' against a dealer 2, 3, 4, 5, 6, 10 & Ace and you should 'switch' against a dealer 7, 8 & 9. (According to the simulator).

I was a little surprised, I thought that it would have been a 'switch' against a dealer 5 & 6 and a 'no switch' against a dealer 7 & 8. Just shows my hunches are useless :)

If anyone has a particular 'switch' or a pair of hands that they want to see 'switches' to then let me know.
 

UK-21

Well-Known Member
#22
Geoff Hall said:
. . .With the hands above, you should 'not switch' against a dealer 2, 3, 4, 5, 6, 10 & Ace and you should 'switch' against a dealer 7, 8 & 9. (According to the simulator).
Hmmm . . . who programmed the simulator? Switching a 21 against a dealer 7,8 or 9 would be silly - it's virtually a guaranteed win. A 20 would be a likely win, but would leave a window open to lose, and an A,6 at a high count against a 7,8 or 9 is only marginally better than a 10,6. And not switching against a 6 at a high count??? By doing so you'd end up with a 20 and an A,6 double opportunity with a relatively high probability of the dealer busting?

I'm not a believer in challenging the maths with hunches, but sometimes hunches that are based on study and experience are not completely out of place and are worth following. In the example above, even if the sim is mathematically correct (again hmmm . . . ) there'll be very little in it.
 

ycming

Well-Known Member
#23
Interesting question that!

Could you post up a list of casino in uk that has the blackjack switch?

OH and in the newcastle casino, they don't let you switch away from a blackjack!

Ming
 

Geoff Hall

Well-Known Member
#24
UK Casinos

ycming said:
Interesting question that!

Could you post up a list of casino in uk that has the blackjack switch?

OH and in the newcastle casino, they don't let you switch away from a blackjack!

Ming
As I've been away for the most part before Christmas I'm not sure which casinos have the game. However, I will find out soon and will be listing them on my website. Hopefully not too many will remove the game after the trial has finished.

Will let you know when I have the list.
 

ycming

Well-Known Member
#25
Geoff Hall said:
As I've been away for the most part before Christmas I'm not sure which casinos have the game. However, I will find out soon and will be listing them on my website. Hopefully not too many will remove the game after the trial has finished.

Will let you know when I have the list.
many thanks, which is your website? is it (Dead link: http://www.blackjackswitch.com/?)

Ming
 

Geoff Hall

Well-Known Member
#27
Switching away from a 'Blackjack' ?

UK-21 said:
Hmmm . . . who programmed the simulator? Switching a 21 against a dealer 7,8 or 9 would be silly - it's virtually a guaranteed win. A 20 would be a likely win, but would leave a window open to lose, and an A,6 at a high count against a 7,8 or 9 is only marginally better than a 10,6. And not switching against a 6 at a high count??? By doing so you'd end up with a 20 and an A,6 double opportunity with a relatively high probability of the dealer busting?

I'm not a believer in challenging the maths with hunches, but sometimes hunches that are based on study and experience are not completely out of place and are worth following. In the example above, even if the sim is mathematically correct (again hmmm . . . ) there'll be very little in it.
Hi UK-21,

I wanted to check whether the simulator gave the correct decisions in the above example so I went to Mike Shackleford's site where he lists the ev's for each player hand verses the dealer upcard for 'Blackjack Switch'. Incidentally, the 'Switch' simulator was programmed by a highly regarded Blackjack programmer who was also responsible for the well known SBA product.

We are dealt A,10 and 10,6 and we can 'switch' to 10,10 and A,6. The simulator produced a 'switch' verses a dealer 7,8 & 9 and a 'no switch' for all other dealer upcards.

Looking at the ev's on Mike's site, the following numbers were attained for each hand and dealer upcard :-

A,10 obviously this is an instant winner so is worth 1.00 of the players bet (as it pays 1/1 and assuming dealer does not have a 'Blackjack').

Looking at 10,6 we get :-

Dealers Upcard 2 3 4 5 6 7 8 9 10 A

Value of 10.6 -0.44 -0.34 -0.30 -0.26 -0.21 -0.43 -0.48 -0.53 -0.56 -0.56

Adding the ev to the 'Blackjack' ev we get :-

BJ + 10,6 EV 0.56 0.66 0.70 0.74 0.79 0.57 0.52 0.47 0.44 0.44

Looking at the ev's for 10,10 and A,6 we get :-

Value of 10,10 0.48 0.55 0.56 0.58 0.59 0.71 0.73 0.70 0.55 0.55
Value of A,6 -0.15 -0.07 -0.03 0.01 0.07 0.00 -0.12 -0.19 -0.24 -0.26

10,10 + A,6 EV 0.33 0.48 0.53 0.59 0.66 0.71 0.61 0.51 0.31 0.29

Looking at the total EV for both hands against each dealer upcard :-

Dealer Upcard (A,10 + 10,6) (10,10 + A,6) Correct Decision

2 0.56 0.33 NO SWITCH
3 0.66 0.48 NO SWITCH
4 0.70 0.53 NO SWITCH
5 0.74 0.59 NO SWITCH
6 0.79 0.66 NO SWITCH
7 0.57 0.71 SWITCH
8 0.52 0.61 SWITCH
9 0.47 0.51 SWITCH
10 0.44 0.31 NO SWITCH
A 0.44 0.29 NO SWITCH

So, the correct play is to 'Switch' against a dealer 7, 8 and 9 and to stay against the other upcards which is what the simulator computed. A dealer 9 upcard is a close decision and I would imagine that high counts may affect the decision although there is a considerable gap in ev in the 'switch' decisions against a dealer 4, 5 and 6.
 

UK-21

Well-Known Member
#28
Thank's for your efforts. I'm sure the numbers spot on. Surprising but there you go - I'm not about to argue maths with Mr S.

Personally, I still think if I was dealt those hands I'd still be inclined to go for the guaranteed win, and probable loss (thereby not losing anything overall), rather than leaving a window open to lose both hands - despite the long term probabilities suggesting it's mathematically correct to do so. But that's me - I tend to play a bit risk adverse.

This looks to be a game of two strong hands, just like Pai Gow Poker, and those are the ones where the money will be made. If you have one strong hand and one weak one (as in the example discussed above), it might be better to engineer a push, save your money and play another, rather than slavishly following the maths because they indicate over millions of hands one option is worth a quid more on the return on a ten pound bet than the other? I know the maths purests will take an opposite view.

Cheers.
 

SystemsTrader

Well-Known Member
#29
UK-21 said:
Personally, I still think if I was dealt those hands I'd still be inclined to go for the guaranteed win, and probable loss (thereby not losing anything overall), rather than leaving a window open to lose both hands - despite the long term probabilities suggesting it's mathematically correct to do so. But that's me - I tend to play a bit risk adverse.
This makes you the type of customer the casino wants.
 
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