7 Card Poker Hand Evaluator

Question

Does anyone know a fast algorithm for evaluating 7 card poker hands? Something which is more efficient than simply brute-force checking a every 21 5-card combination of hands fr

Answer 1

I think you should do the 21 combinations and use some kind of 7462 table. 1st: any 7 cards have 21 different 5 cards combinations 2nd: every possible final poker hands (2.598.960) represents one of 7462 different kind of hands so, it´s easy.

You just have to look at every 21 combinations of your cards and, for each one, see the ranking of 7462 ranking table. http://www.sendspace.com/file/pet0dd

Then, for each 7 cards you will have 21 different rankings from this 7462 table i made. The highest ranking of 21 combinations is the one you want to know.

To understand the table: In every line you have the 5 card hand (Z for suited, Y non-suited) and you have the ranking of it. That´s only you need. I give you the table and an example algorithm. It´s not really the code. It´s visual basic format and i wrote it now. probably doesn´t work but you should understand. The code would be something like this:

'############### 1st: Define your hand, for example "2c2d2h2s3c3h3s" #############################################################################################

Dim mycard As New ArrayList

mycard(1).Add("2c")
mycard(2).Add("2d")
mycard(3).Add("2h")
mycard(4).Add("2s")
mycard(5).Add("3c")
mycard(6).Add("3h")
mycard(7).Add("3s")
mycard.Sort() '################# you need to sort in alphabeticall order to match it later with 7462 table #############################################



' ################## 2nd: Let´s transform it to every kind of 5 cards combinations (21). It will also preserve the alphabeticall order ##################################

Dim myHand5 As String = ""
Dim suited as String = ""
Dim ranking as Integer = 0
Dim myranking as Integer = 7462
Dim mystring as String = ""

For cicle1 = 0 to 2
     For cicle2 = cicle1 + 1 to 3
          For cicle3 = cicle3 + 1 to 4
               For cicle4 = cicle3 + 1 to 5
                    For cicle5 = cicle4 + 1 to 6
                         myhand5 = left(mycard(cicle1),1) & left(mycard(cicle2),1) & left(mycard(cicle3),1) & left(mycard(cicle4),1)  & left(mycard(cicle5),1)
                         suited = left(mycard(cicle1),2) & left(mycard(cicle2),2) & left(mycard(cicle3),2) & left(mycard(cicle4),2)  & left(mycard(cicle5),2)
                         if suited = "ccccc" or suited = "ffffffffd" or suited = "hhhhh" or suited = "sssss" then myhand5 = myhand5 & "Z" Else myhand5 = myhand5 & "Y"  
                          ranking = 0                              
                          FileOpen (1, "7462.txt", Input)
                          Do
                               ranking = ranking + 1
                               Input(1, mystring)
                               Input(1, ranking)
                               If mystring = myhand5 Then 
                                    If ranking < myranking then myrankin = ranking
                               End If
                          Loop Until EOF(1)
                          FileClose(1)
                    Next cicle5
               Next cicle4
          Next cicle3
     Next cicle2
Next cicle1

Final ranking is myranking variable. You should know your hand in less than a second. And also is good to compare with other hands, because you have the ranking value not the name of it. And if you want to do something with poker algorithms, this is where you should start. With ranking values everything is quick and easy.

Note: I´m not a programmer. I am a wanna be. I understand some visual basic functions. I whish i knew how to make real programs. If the algorithm works, please leave a comment. If you want it to be very very fast, i don´t know how to do it. I whish i have an ultra fast algorithm that allows me check (in real time) my odds against any opponents in every stage of the game. I tried many algorithms to calculate my odds at the flop in real time but the fastest i can is 30 seconds. Now, i can calculate my odds at the flop in 3 seconds but i use a 150 gigabytes database with many things pre-calculated. If you want to know your odds in real time you should have many things pre-calculated. That´s how i did.