blackjack odds

[mike1212]

There is a site offering this (5dimes) as a promotion. Does the no double downs nulify the benefit of 2 to 1 on blackjacks? What's the expected value of this game?



• Hands dealt from an 8 - deck shoe
• After each hand is played, a new 8 - deck shoe is used to deal the next hand
• Blackjack pays 2 to 1
• Dealer hits on soft 17
• No double down
• Split pairs once
• No surrender
• Valid only at promotional table

[cardcounter0]

The no double down rule adds about -.7% to the house edge. 2:1 Blackjacks gives the player +2.263%. Adding up all the rules disadvantages/advantages:

The game has .7% +EV to a basic strategy player.

8 deck H17 -.766
No DD -.66~~
SPL1 -.035
ENHC -.11
2:1 BJ +2.263

[BruceZ]

[ QUOTE ]
The no double down rule adds about -.7% to the house edge. 2:1 Blackjacks gives the player +2.263%. Adding up all the rules disadvantages/advantages:

The game has .7% +EV to a basic strategy player.

8 deck H17 -.766
No DD -.66~~
SPL1 -.035
ENHC -.11
2:1 BJ +2.263

[/ QUOTE ]

The no double down rule is more costly to the player than that, it's -1.3, according to the ultimate source, Peter Griffin's The Theory of Blackjack. Adding up the costs of no doubling on 11 (-.73), 10 (-.45), 9 (-.076) and soft doubling (-.083) gives -1.339. These are the numbers for infinite deck, which are slightly less negative than for 8 deck, but the difference is negligible, so I didn't interpolate. These numbers are also in line with Thorp's for single deck. We essentially agree on the rest, but this makes the game much closer to even:

8 deck H17 -.565 -.22 = -.785
No DD -1.339
SPL1 -.039
2:1 BJ +2.25
-------------------------------
+.087

Where are your doubling numbers from?

Also, what is ENHC? European no hole card? Why did you include this? He said no surrender, which is standard.

[cardcounter0]

I didn't have a number for No Doubling, tried to expolate from my numbers for Doubling only on 11 and Doubling only on 11,10. I didn't realize these number were in "Theory of Blackjack", I'm glad we agree on the rest of them. ;>)

ENHC stands for European No Hole Card, I am assuming the dealer takes ALL bets if he turns up a blackjack after the player has played his hand. (Splitting aces with a dealer T up, dealer gets blackjack, player loses both bets. -- there is a slight penality for this -.011)

But 8 deck 2:1 BJ, Blackjack is ever so slightly more frequent with 8 decks than infinite decks, so your -2.25 is slightly off the 2.263 number, so it is a wash.

I would say that your +.08 EV number is almost exactly spot on.

Thanks for spotting my error, I'll have to check "Theory of Blackjack" again and go over my numbers.

[cardcounter0]

Re-read the original post, and I saw it wasn't ENHC rules.

So ....

8 decks -.55
H17 -.216
SPL1 -.035
No DD -1.339
===
-2.14

add 2:1 BJ advantage of +2.263

>>> +EV of .123 <<<