Hi all.
I play a lot of DONs and I am interested in studying them further. I am currently trying to write my own software to do some database analysis, and as part of this I am hoping to determine how to compute equity based on chip stacks.
For example, if the tournament is a 6max 10$ DON, and there are 4 people left with stacks
2000
2500
3000
1500
What equations should I be using to compute each player's equity of the prize pool? Remember that this is a DON and each places 1-3 pay the same.
So I found this website...
http://www.thehendonmob.com/matthew_hilger/tournament_equity
I made a program to do this calculation. For the example above with stacks
2000
2500
3000
1500
In a 6 max DON with 5$ buyin I get the following equity results:
7.30$
8.06$
8.55$
6.09$
Can anyone verify that I am doing this correctly?
What language are you using? I think I have one in C, python, and maybe a couple more if you need them.
Your numbers are correct BTW, verified with http://www.icmpoker.com/Calculator.aspx
If you are only considering 6max DONs, you could definitely work out a closed form formula. ICM doesn't get really ugly until 4+ payouts.
I am using C, here is the code I wrote in case you are knowledgeable in such an area:
double *DONequitycalc(double *chipcounts, int numplayers, double prizepool, double placespaid)
{
int i,j,k;
double p1[numplayers+1]; //probability of getting first based on ICM
double p2[numplayers+1]; //probability of getting second based on ICM
double p3[numplayers+1]; //probability of getting third based on ICM
double totalchips; //total chips in play
double *equity = malloc(numplayers * sizeof(double)); //add up p1,p2,p3 and muiltiply by prize to get equity
/*initializing variables*/
totalchips=0;
for(i=1;i<=numplayers;i++)
{
totalchips += chipcounts;
p1=0;
p2=0;
p3=0;
equity=0;
}
/*probability of first is chipstack divided by total chips*/
for(i=1;i<=numplayers;i++)
{
p1=chipcounts/totalchips;
}
/*adding up conditional probabilities to get probability of second*/
for(i=1;i<=numplayers;i++)
{
for(j=1;j<=numplayers;j++)
{
if(i!=j)
{
p2 += p1[j]*(chipcounts/(totalchips-chipcounts[j]));
}
}
}
/*adding up conditional probabilities to get probability of third*/
for(i=1;i<=numplayers;i++)
{
for(j=1;j<=numplayers;j++)
{
for(k=1;k<=numplayers;k++)
{
if((i!=j)&&(i!=k)&&(j!=k))
{
p3 += p1[j]*(chipcounts[k]/(totalchips-chipcounts[j]))*(chipcounts/(totalchips-chipcounts[j]-chipcounts[k]));
}
}
}
}
/*calculating equity for each player*/
for(i=1;i<=numplayers;i++)
{
equity = (p1+p2+p3)*(prizepool/placespaid);
printf("EQUITY %d is %.02f\n",i,equity);
}
return equity;
}
I now have a fully functional program that analyzes my xml files from Titan poker tournaments and extracts all the preflop play into a separate file. I'm going to try and compile this information into a database in order to get an idea of ranges in different spots preflop. Hopefully, using the equity program I just wrote, I can analyze my hands and fix some leaks in my game.
