Question

I need to render a win loss chart based on player performance, I was hoping someone will have experience with similar calculations.

So here is what I have:

public class Player
{
   public virtual bool IsWinner { get; set; }
}

//Sample list
var listOfPlayers = new List<Player>
                                  {
                                      new Player{ IsWinner = true },
                                      new Player{ IsWinner = false },
                                      new Player{ IsWinner = false },
                                      new Player{ IsWinner = true },
                                      new Player{ IsWinner = true },
                                      new Player{ IsWinner = false },
                                      new Player{ IsWinner = true }
                                  };

The players list comes from Database and basically each player in the list belongs to a different match.

So I have this function where I am supplying the list of players and the respective index in the list:

So lets say for example that at index 2 I have one win and 2 losses, because I am rendering a chart I need this function to return a double that will represent the win/loss percentage so it will have (player won 25%of matches 0-3)

public double CalculateWinLossPercentage(List<Player> listOfPlayers,int index)
{
    double winpercentage = null;
    //calculate win percentage base on the total list of players 
    //and the current index in list
    return winpercentage;
}

Thank you in advance for your help.

Answer 1

public double CalculateWinLossPercentage(List<Player> listOfPlayers,int index)
{
    int count = listOfPlayers.GetRange(0, index + 1).Count(p => p.IsWinner);
    return ((double)count)/(index+1);
}

This will return the percentage as a double (number between 0 and 1).
Also, in your example, with index = 2, the correct result would be 33.3%, not 25%.