CapJack
Joined: Dec 30, 2017
• Posts: 6
January 2nd, 2022 at 11:35:35 AM permalink
I'm relatively new in AP and still trying to grasp all the details. For example, in Basic Strategy, whether you should DD with a 9 vs. a Dealer 2 depends on table rules. If you are playing a double deck game, DHS17, DAS allowed, you SHOULD DD on a 9 vs. Dearer 2. In looking at the Illustrious 18 chart, Player 9 vs. a Dealer 2 is a +1, regardless of # of decks. So in this case, is the I18 saying ONLY DD if the TC is +1 or higher? If so, why does BS say DD to begin with?
kewlj
Joined: Apr 17, 2012
• Posts: 4626
Thanks for this post from:
January 2nd, 2022 at 12:16:55 PM permalink
You can have a slightly different index number for a number of plays depending on the exact rules of the game, including number of decks (as you mentioned), as well as depending on how what the player does with his count as far as rounding off, flooring ect. You are always talking about a difference of 1 number, example double down @ 2 vs double down @ 1. The difference is minimal. I mean really it is a matter of pennies. Most players should learn one set of index numbers for the game they play most frequently. Don't waste a lot of mental energy learning more than one set of numbers when it adds almost nothing.

Now if you are a serious player, professional or playing serious money supplementing your income or such, I recommend you consider something called Card Counter's Basic Strategy. This has one basic strategy that you play for all counts, which will eliminate the "tell" of playing the same hand differently at different times. The way it works is you make the correct play for the higher counts, when you have your bigger bets out at all times, but making that play at a neutral count of zero, may be slightly wrong (at a cost of pennies), but it is always correct play when you have larger bets out. It is a form of cover.

So for 9 vs 2 for example, the technically correct play would be to hit at TC 0, and double at TC +1 or +2 (I use +2) depending on exact rules and decks. So Card Counter's Basic Strategy would have you ALWAYS double 9 vs 2. This will be the correct play when all your larger bets are out and just slightly incorrect (at a cost of pennies) at a neutral count, BUT you have eliminated the "tell" of playing the same hand differently. This is a major deal for longevity, especially for a player with a limited rotation, playing 1, 2, or 3 casinos regularly.
Last edited by: kewlj on Jan 2, 2022
Kellynbnf
Joined: May 5, 2010
• Posts: 196
January 2nd, 2022 at 3:55:19 PM permalink
In a double deck game you have either two or three low cards (using Hi-Lo) on the table when you start this hand, so when you get 9 vs. 2 on the first hand after a shuffle you already have a TC of +1 or +1.5. That explains why with one or two decks this hand is a BS double, whereas with more decks the absolute value of an initial TC after such a hand would be less (and thus BS would be to hit).
CapJack
Joined: Dec 30, 2017
• Posts: 6
January 2nd, 2022 at 9:54:12 PM permalink
That makes total sense and the best answer provided of any BJ forum where this question has been posted.

Thank you.
aceside
Joined: May 14, 2021
• Posts: 136
January 8th, 2022 at 10:54:06 AM permalink
Quote: Kellynbnf

In a double deck game you have either two or three low cards (using Hi-Lo) on the table when you start this hand, so when you get 9 vs. 2 on the first hand after a shuffle you already have a TC of +1 or +1.5. That explains why with one or two decks this hand is a BS double, whereas with more decks the absolute value of an initial TC after such a hand would be less (and thus BS would be to hit).

This has been discussed previously. The issue is about the TC difference before and after the hand was dealt. However, for a card counter, no doubt you must use the after dealt TC.

On a different note, the TC deviation index inherently varies with the number of decks being used, so, for the hand 9 vs 2 decision, I am still not clear which one is the the main cause of this discrepancy. Can you explain a little more into this?
Romes
Joined: Jul 22, 2014
• Posts: 5552
January 11th, 2022 at 9:01:06 PM permalink
Quote: CapJack

I'm relatively new in AP and still trying to grasp all the details. For example, in Basic Strategy, whether you should DD with a 9 vs. a Dealer 2 depends on table rules. If you are playing a double deck game, DHS17, DAS allowed, you SHOULD DD on a 9 vs. Dearer 2. In looking at the Illustrious 18 chart, Player 9 vs. a Dealer 2 is a +1, regardless of # of decks. So in this case, is the I18 saying ONLY DD if the TC is +1 or higher? If so, why does BS say DD to begin with?

If you're playing DD the reason it's basic strategy is because any combination of hard 9 v 2 will make the count either +2 or +3, which in double deck and first hand equates to > TC +1.

example: 7-2 vs 2... the running count is +2 and thus the TC is slightly greater than +1.

Basic strategy doesn't consider independent deck composition... that's what counting does. Basically that means it assumes the deck is shuffled every time you have a decision to make.
Playing it correctly means you've already won.
charliepatrick
Joined: Jun 17, 2011
• Posts: 2577
January 12th, 2022 at 12:16:45 PM permalink
There are a few plays that change with fewer decks. This is usually because the cards you and the dealer have slightly alter the optimal play from infinite decks.

The clearest example is standing on 7,7 vs 10 single deck; that's because two of your sevens have gone (to make you 21) and if you make (say) 18, some sevens for Dealer's 17 where you'd win, have gone. In this case you have the good cards that you need.

With doubling 9 vs 2, there are three low cards gone, so your chances of getting (say) a 10 or Ace are slightly higher with fewer decks. In this case you already have some of the bad cards meaning you're just slightly better off than normal. Similarly 10.3 vs 2 or 10,2 vs 4, just having the one 10 means it can be better to hit than stand with fewer decks.
tyler498
Joined: Jun 24, 2017
• Posts: 176
January 12th, 2022 at 7:51:46 PM permalink
Quote: kewlj

You can have a slightly different index number for a number of plays depending on the exact rules of the game, including number of decks (as you mentioned), as well as depending on how what the player does with his count as far as rounding off, flooring ect. You are always talking about a difference of 1 number, example double down @ 2 vs double down @ 1. The difference is minimal. I mean really it is a matter of pennies. Most players should learn one set of index numbers for the game they play most frequently. Don't waste a lot of mental energy learning more than one set of numbers when it adds almost nothing.

Now if you are a serious player, professional or playing serious money supplementing your income or such, I recommend you consider something called Card Counter's Basic Strategy. This has one basic strategy that you play for all counts, which will eliminate the "tell" of playing the same hand differently at different times. The way it works is you make the correct play for the higher counts, when you have your bigger bets out at all times, but making that play at a neutral count of zero, may be slightly wrong (at a cost of pennies), but it is always correct play when you have larger bets out. It is a form of cover.

So for 9 vs 2 for example, the technically correct play would be to hit at TC 0, and double at TC +1 or +2 (I use +2) depending on exact rules and decks. So Card Counter's Basic Strategy would have you ALWAYS double 9 vs 2. This will be the correct play when all your larger bets are out and just slightly incorrect (at a cost of pennies) at a neutral count, BUT you have eliminated the "tell" of playing the same hand differently. This is a major deal for longevity, especially for a player with a limited rotation, playing 1, 2, or 3 casinos regularly.