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Thread: MGP CA: Spanish 21

  1. #1


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    MGP CA: Spanish 21

    Hi All,

    New member here just found this forum on google, looks like a wonderful community excited to get in and add what I can.

    The impetus for this google is some analysis I'm trying to do on Spanish 21. Has anyone successfully used MGP CA for this game?

    I can reproduce the basic strategy chart from Michael Shackleford's Spanish 21 page which matches the one in the Pro's Guide to Spanish 21 and Australina Pontoon by Katrina Walker, but can't get the house edge to agree. They both say it should be 0.40% for the rules they define here: https://wizardofodds.com/games/spanish-21/ plus 0.0036% extra for the suited 7-7-7 super bonus on a $25 bet.

    MGP CA for me, including the super bonus, keeps spitting out 0.66% house edge. I've included a pdf with screenshots of all of my configuration options and the output that shows what I am talking about here: https://filebin.net/qkxqyebnmswx6ir0

    (too big to upload sorry for link, let me know if this isn't ok)

    Any ideas what I am doing wrong? Is it a configuration error on me or is this software not set up for S21? It seems like all of the needed rule changes and bonuses are features that are supported.

    Thanks in advance if anyone takes the time to look at this, even if it ultimately isn't resolved. Grateful for anyone who does, I know this isn't a charity.

    Megalodon

  2. #2
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    Under the “player’s 21 always wins” tab, check the payoff of 1.5 on blackjack push, and you will be all good.

  3. #3


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    You haven’t included all the set up pages in your pdf file but here’s a few ideas…

    • Open the Double tab and uncheck “Player 21 Always Wins Including BJ/Post-Double”.
    • Open the Special Rules tab and uncheck “Player 21 Always Wins Including BJ/Post-Double”, then in the Player-Dealer Playoffs box your hand totals should be changed to Push for 17 – 20 inclusive and Player Wins for 21 and BJ. The Toggle All box should be set to Push.
    • Open the Bonus Rules tab and delete the Spanish 7-7-7 Small Bet Super Bonus entry.

    You should then have five entries in the “Bonus Rules Applied” Box which you need to make the following changes:

    6-7-8

    Set the Dealer BJ Payoff to -1 for the General, Suited and Spades Bonus boxes.
    Set 6,7 and 8 to 1 in the horizontal box below “Rule Based on Hand Composition”

    7-7-7
    Set the Dealer BJ Payoff to -1 for the General, Suited and Spades Bonus boxes.
    Set 7 to 3 in the horizontal box below “Rule Based on Hand Composition”

    Set the Dealer UC Payoff as follows:
    General: 0 (Dealer UC should be set to 7)
    Suited: 100
    Spades Bonus: 100

    5-Card 21
    Set the Dealer BJ Payoff to -1 for the General tab only.

    6-Card 21
    Set the Dealer BJ Payoff to -1 for the General tab only.

    7-Card 21
    Set the Dealer BJ Payoff to -1 for the General tab only.

    Then rerun MGP’s CA with the above changes and note the Total Dependent Strategy Net EV. If correct, you can save the rule file as a template for future use.
    Casino Enemy No.1

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    Quote Originally Posted by davethebuilder View Post
    You haven’t included all the set up pages in your pdf file but here’s a few ideas…
    This is wonderful! Let me add a little bit more.
    The 777+7 Super Bonus lowers the house edge by 0.036% in an 8-deck game.
    Last edited by aceside; 08-23-2021 at 09:19 AM. Reason: I figured out the problem myself.

  5. #5


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    OP checking in here:

    1) Thank you for the help!
    2) The biggest difference was from the not handling the player winning 1.5 units on player and dealer blackjack, this got me most of the way there to quite a reasonable EV.
    3) A question about the super bonus. There are two 7-7-7 bonuses that I am trying to analyze: one is a bonus for getting to 21 normally, applies post split, and pays 3:2 if not suited, 2:1 if suited and 3:1 if spaded, regardless of the dealer upstart. The other is the 777+7 super bonus that pays 200-1 if you have three suited 7s pre split and dealer has a 7 of any suit. I imagine possible to just special case this in after the fact with the .036% figure that aceside provided, but believe it will actually chance the strategy to hit rather than split with suited 7s vs a 7, which I'd like to capture if possible, which is what I was trying to work out with the super bonus small bet.

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    Quote Originally Posted by Megalodon View Post
    The other is the 777+7 super bonus that pays 200-1 if you have three suited 7s pre split and dealer has a 7 of any suit. I imagine possible to just special case this in after the fact with the .036% figure that aceside provided, but believe it will actually chance the strategy to hit rather than split with suited 7s vs a 7, which I'd like to capture if possible, which is what I was trying to work out with the super bonus small bet.
    The super bonus pays $1000 for bets less than $25 and $5000 for bets of $25 or more. So it only pays 200 to 1 if you are betting exactly $5 or $25 and the 0.036% figure (from https://wizardofodds.com/games/spanish-21/) is based on those bet sizes. Basic strategy by a wide margin is to hit any suited 7,7 vs 7 for those bet sizes. Because the EV of the super bonus decreases as your bet size increases, there is actually a threshold beyond which going for it is no longer the correct play. This threshold also depends on whether your pair is spaded and/or suited with the dealer's 7. The details are in table 3.8 of Katarina Walker's book (page 17 in my copy).

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    Quote Originally Posted by Gronbog View Post
    Because the EV of the super bonus decreases as your bet size increases, there is actually a threshold beyond which going for it is no longer the correct play. This threshold also depends on whether your pair is spaded and/or suited with the dealer's 7. The details are in table 3.8 of Katarina Walker's book (page 17 in my copy).
    This threshold is not hard to calculate. If the bet amount is $25, the payoff is 200:1; If the bet amount is $250, the payoff is 20:1. Based on this, I find the threshold to be $32. Is this correct? By the way, can you email me a copy of the Walker book?

  8. #8
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    Aceside, you have asked someone to violate the law. Do not do that here.
    "I don't think outside the box; I think of what I can do with the box." - Henri Matisse

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    0 out of 1 members found this post helpful. Did you find this post helpful? Yes | No
    I just noticed two comments on my number above. Apparently the $32 above is wrong, so I revise it now. If the dealer shows a 7 of spades, the threshold is $2069, and if the dealer shows a 7 of non spades, the threshold is $2140.

  10. #10


    1 out of 1 members found this post helpful. Did you find this post helpful? Yes | No
    OP,

    I suggest that before you try to analyse any one off rule make sure that your Spanish 21 rule file is correct. If you’ve made the changes above link a pdf file with all pages included as well as the results sheet showing the Net EV.

    Generally speaking, the house edge of the Super Bonus is determined by the number of decks, the bet size and the number of players. There is also an “Envy Bonus” which is an amount paid to all other players at the table if a player should win and that has its own separate house edge. The player strategy depends on the bet size, card composition and the count.

    One point to remember is that in the long run you will only get the chance to go for the Super Bonus around once every 8,954 hands in a six deck game and you still get paid according to the rules of the game for any 7-7-7. So this aspect of the game is not going to make much difference to your long term results.
    Casino Enemy No.1

  11. #11


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    Aceside,

    Please read more and post less and stop posting rubbish as Spanish 21 and its variants are hard enough to analyse without your distractions. Your posts could also be harmful to new players.
    Casino Enemy No.1

  12. #12


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    Quote Originally Posted by davethebuilder View Post
    Aceside,

    Please read more and post less and stop posting rubbish as Spanish 21 and its variants are hard enough to analyse without your distractions. Your posts could also be harmful to new players.
    Such is the modus operandi of the experienced troller. Good post.

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    Quote Originally Posted by Freightman View Post
    Such is the modus operandi of the experienced troller. Good post.
    First, I notice people from the Southern Hemisphere are more direct in expressing themselves.
    Seond, the OP Megaloton just said I was helpful, but you were saying the opposite.
    Third, I will buy a Katarina book to find out what is in table 3.8 on page 17. I haven’t got what I asked for.
    Last edited by aceside; 08-30-2021 at 05:27 PM.

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