public class Spel
    {
        private Dealer _dealer;
        private List<Speler> _spelers;
        private int _ronde;
        private Tafel _tafel; //// <---------------------------------

        public List<Speler> Spelers { get { return this._spelers; } }

        public Spel(Tafel tafel) //// <---------------------------------
        {
            this._tafel = tafel; //// <---------------------------------
            this._dealer = new Dealer();
            this.Start();
        }