listi.net

Blackjack

Rules for dealer

Automating the dealer play

https://cherper.com/showlist2.asp?parent=52042

Examine blackjack

Simulate the play

Play and learn the best strategies.

Rules of Blackjack

It's you vs. the dealer

You place a bet and then you're dealt 2 cards face up

and the dealer get 2 cards one face up and one face down

Your goal is to get as close to 21 points without going over

If you exceed 21 you lose

Cards 2 - 10 are worth that point value

Ace can be treated as 1 or 11

Jack, Queen, and King are treated as 10 pts.

The dealer must hit if the hand is less than 17 and stick if greater than 16

There is an exception if the dealer has a soft 17 (includes an Ace) then must hit??(not sure)

There are other rules of splitting a hand if you have a pair and playing 2 separate hands, you must double your bet

There is also doubling down where you double your bet and get one more card only

Rules vary amongst casino so check them out

there are alternative rules like insurance and sometimes other side bets

If there is a tie, called a push, no money changes hands

Blackjack doesn't use a fair deck except for when the first card is dealt. The odds of receiving a card, shifts as the cards are dealt. We will do most of the analysis assuming that each card is randomly selected (shuffled before each deal) from a limitless deck. Then we will look at one, two, four, six, and eight-deck games.

For our simulation, we can just generate a random number between 1 and 13, and allow a 1 to mean 1 or 11 and a 11, 12, or 13 to be valued as 10.

For blackjack, we will first program the dealer's rules to see how often various scenarios play out, then we'll look at the basic rules, advanced rules, and then possibly card counting.

Below is the results of my analysis

In 32,051 trials the dealer busts around 30% of the time and doesn't bust 70%.

Dealer getting 20 is the highest percent which makes sense because there are 4 ten-value cards out of 13, which makes the odds of 4/13 or about a 31% chance of being dealt a 10 value (ie 10, Jack, Queen, or King)

Download the spreadsheet from Blackjack.xlsm

Press the Run once button to deal one hand

Press the Run Many to run it over and over until you press Esc to stop the code.

Run Once button



Sub Button1_Click()

gameover = False

Range("D:E") = ""

'a = Array(1, 3, 1, 2, 1)



Do Until gameover

    i = i + 1

    c = [randbetween(1,13)]

    'c = a(i - 1)

    

    If c > 10 Then c = 10

    Cells(i + 1, 4) = c

    Total = Total + c

    If c = 1 Then

       alttotal = alttotal + c + 10

       If alttotal > 21 Then

          alttotal = alttotal - 10

       End If

       

    Else

        alttotal = alttotal + c

    End If

    Range("E1") = alttotal

    Range("D1") = Total

    If (alttotal > 17 And alttotal < 22) Or Total > 16 Then

       

        If alttotal > Total Then Total = alttotal

        gameover = True

        If Total = 21 Then

            Range("dealer21") = Range("dealer21") + 1

        End If

        If Total = 20 Then

            Range("dealer20") = Range("dealer20") + 1

        End If

        If Total = 19 Then

            Range("dealer" & Total) = Range("dealer" & Total) + 1

        End If

    

        If Total = 18 Then

            Range("dealer" & Total) = Range("dealer" & Total) + 1

        End If

        

        If Total = 17 Then

            Range("dealer" & Total) = Range("dealer" & Total) + 1

        End If

        If Total > 21 Then

            Range("dbusts") = Range("dbusts") + 1

        End If

    

    Else

       If Total < 17 And alttotal < 18 Then

       Else

        alttotal = Total

        Range("E1") = alttotal

       End If

       

    End If

    

Loop



End Sub

Run Many Button



Sub Button2_Click()

Do Until Range("I1") <> ""



  Button1_Click

Loop

End Sub

Excersize

Make the code more efficient by using variables instead of spreadsheet fields

Exercise

Calculate the odds of the dealer busting with various up cards A - K

The next thing we will do is determine the odds of doubling down.

Add a chart and some more features

Let's develop and run a number of simulations of doubling down.

With an Ace

Hard hand (no Ace)

Dealer's up card

With card counting

How many times in a row should the dealer bust based on the number of hands played