Basic Strategy Engine updated

I just installed an update to the Blackjack Basic Strategy Engine to refine the early surrender strategies.

A handful of decisions weren't perfect in the early surrender strategies. They are now, as far as I know. The decisions in question were what to do with hard 8 vs Ace, and also some decisions with (8,8) and (7,7) vs T. (You shouldn't early surrender 88vT in single deck if DAS is allowed.)

A reminder is in order... Early surrender is rare. Most of the time, if you are selecting early surrender in the strategy engine you are making a mistake. Early surrender means that you can surrender BEFORE the dealer checks for blackjack. If you still lose your full bet if the dealer has blackjack, it is not early surrender, but instead the more common late surrender.

One more change was made to the Strategy Engine, and this is more of a philosophical issue. If any kind of surrender is available, I changed the strategy for hard 16 vs dealer ten to 'RS', meaning surrender if possible, otherwise stand. Any 16 you can't surrender is assumed to be three or more cards, so Stand is better than Hit. If you turn off all surrender options, then 16vT shows Hit, since that is the best Total-Dependent strategy including two-card sixteens. The bottom line is: Don't turn on surrender in the engine if surrender isn't really available to you.

KenSmith said:

. (You shouldn't early surrender 88vT in single deck if DAS is allowed.) .

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Ken, I'll always keep that play close to my heart and pray for the day I need to use it (maybe not in this lifetime, though).:sad:

Heh, you and me both. Somehow, there just aren't that many single deck DAS early surrender games out there. :grin:

KenSmith said:

Heh, you and me both. Somehow, there just aren't that many single deck DAS early surrender games out there. :grin:

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Just let me know where and we can team up. I'll even let you share my BR in appreciation for the info. Meanwhile, I'll have my travel bag all ready just in case. BTW, can we bring Zg along? :cool2:

KenSmith said:

I just installed an update to the Blackjack Basic Strategy Engine to refine the early surrender strategies.

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Thanks Ken - if any suggestion I may have made helped you in any way, it pales compared to how you have helped me many times in the past, long before I ever made a single post here, just because you chose to take the time to help out a complete stranger.

Just wanted to say that lol.

And I'll take that "I'll give that a definite maybe." stuff lol. Sounds interesting

Kasi said:

you have helped me many times in the past, long before I ever made a single post here, just because you chose to take the time to help out a complete stranger.

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I'd also like to thank you for creating and hosting the kickassest basic strategy engine on the Internet.

Grrr. :whip:

Very frustrating. Two errors occurred in my recent update. 15vT stopped showing as an early surrender in single deck. That was the result of a simplification in the code that went awry.

Also, 2D H17 inaccurately advised early surrender of (4,4). That was just a transposition error from my summary spreadsheet to the code.

Both issues are corrected. I won't even claim they're all correct now, despite my double-checking every single one of them. Again.

I hope I don't have any need to edit ANYTHING in the charts anytime soon. Fortunately, I think some of my other planned enhancements won't require chart updates, just house edge updates.

In the ENHC game you cannot surrender against the Ace. In this case the HA of 0.08% would be misleading.

Any way you can make it so the dealer's hole card is shown after surrender?

3 card 16

KenSmith said:

One more change was made to the Strategy Engine, and this is more of a philosophical issue. If any kind of surrender is available, I changed the strategy for hard 16 vs dealer ten to 'RS', meaning surrender if possible, otherwise stand. Any 16 you can't surrender is assumed to be three or more cards, so Stand is better than Hit. If you turn off all surrender options, then 16vT shows Hit, since that is the best Total-Dependent strategy including two-card sixteens. The bottom line is: Don't turn on surrender in the engine if surrender isn't really available to you.

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Regardless of surrender, is it better to hit or stand a 3+ card 16 or not? There seems to be a bit of confusion on this issue.

http://www.blackjackinfo.com/bb/showthread.php?t=11193

Mr. T said:

In the ENHC game you cannot surrender against the Ace. In this case the HA of 0.08% would be misleading.

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One of the planned features is the ability to choose ES/LS vs 2-9, NS vs Ace. But, I do know there was at least once a game that offered early surrender (even against the Ace) but no hole card was dealt for the dealer. It was actually run as a "peek" style game though, because if you lose more than the initial bet, your bet was held until the dealer didn't have blackjack. This was at a small casino in the US, circa 1990.

Blue Efficacy said:

Any way you can make it so the dealer's hole card is shown after surrender?

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This is a strategy trainer issue, whereas the rest of this thread is about the strategy engine. Still, it's a good idea. No time frame for when that might happen though.

jay28 said:

Regardless of surrender, is it better to hit or stand a 3+ card 16 or not? There seems to be a bit of confusion on this issue.

http://www.blackjackinfo.com/bb/showthread.php?t=11193

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I thought that thread was fairly clear on the case. yes, standing on 3+ card 16vT is better than hitting.

Now I know this is basic stratagy but are there any plays that are basically a coin flip that will reduce you risk and decrease your variance?

1357111317 said:

Now I know this is basic stratagy but are there any plays that are basically a coin flip that will reduce you risk and decrease your variance?

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The closest play I'm aware of is A2 v 5 in a 8 Deck S17 game, the difference between doubling and hitting of the hand is 0.000029. For the answer to the rest of your question follow the link

(Dead link: http://www.advantageplayer.com/blackjack/forums/bj-main/webbbs.cgi?read=19604)

I just wanted to thank you for this great site and your strategy engine. it is the best I have found.

I take screen shots of all the BS charts, print them out and then write in my HiLo index plays. These charts along with a deck of cards are always with me.

cheers

I think this should be stickied, anyone else? Basic stratagy is the most powerful system ever devised against the game of blackjack.

Just a couple questions about the differences of H17 and S17. In S17 you hit on 11vsA and in H17 you double. Also In H17 you double A8 vs 6 and A7 vs 2 and in S17 you stand both of those. Now this makes no sense to me. Now I know that math supports this but doesnt H17 give the dealer a better chance of making an 18-21 and how does hitting a soft 17 change the basic stratagy play of A7 vs 2?

Besides A2 v 5 in an 8 Deck S17 game, another extremely close decision is A4 v 4 in an 8 deck game.

If you look at the charts in Blackjack Attack and Theory of Blackjack you will see the precise figures for every possible play.

1357111317 said:

...doesnt H17 give the dealer a better chance of making an 18-21 and how does hitting a soft 17 change the basic stratagy play of A7 vs 2?

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Yes H17 does increase the chances of the dealer getting an 18-21 total.

He will also bust slightly more often.

He will also finish with a higher avg total.

Like Flash says, he finishes at 17 a pretty fair amount less often in H17.
And a 17 total is a losing hand. So is 18 lol.

I don't know why the BS changes, except like you say, it does. Sometimes I guess it's just difficult to ratioalize to oneself why, especially with close plays.

Thankfully "ours is not to reason why....".

Ultimately, it's all really a leap of faith, doing it yet not fully understanding why, isn't it?