Forming a tournament table with LINQ (Fixture List)

Question

I have an array of players (string[]) and now I need to get an array of pairs representing games (playerN-playerM) to orginize tournament table like at this picture:

Answer 1

The implementation I really wanted:

public static List>> ListMatches(List listTeam)
{
    var result = new List>>();

    int numDays = (listTeam.Count - 1);
    int halfSize = listTeam.Count / 2;
    var teams = new List();
    teams.AddRange(listTeam.Skip(halfSize).Take(halfSize));
    teams.AddRange(listTeam.Skip(1).Take(halfSize - 1).ToArray().Reverse());
    int teamsSize = teams.Count;

    for (int day = 0; day < numDays; day++)
    {
        var round = new List>();
        int teamIdx = day % teamsSize;
        round.Add(new Tuple(teams[teamIdx], listTeam[0]));

        for (int idx = 1; idx < halfSize; idx++)
        {
            int firstTeam = (day + idx) % teamsSize;
            int secondTeam = (day + teamsSize - idx) % teamsSize;

            round.Add(new Tuple(teams[firstTeam], teams[secondTeam]));
        }
        result.Add(round);
    }
    return result;
}