private boolean checkLeftDiagonalWin(int playerNumber) {
        int criticalNumber = 0;
        int i = 0;
        int j = 0;

        switch (playerNumber) {

            case 1: {

                while (i < gameField.getFieldSize()) {

                    if(gameField.isX(i,j)) {
                        criticalNumber++;
                        i++;
                        j++;
                        continue;
                    }
                    if(gameField.isO(i,j)) {
                        criticalNumber = 0;
                        break;
                    }
                    i++;
                    j++;

                }
            }

            case 2: {

                while (i < gameField.getFieldSize()) {

                    if(gameField.isO(i,j)) {
                        criticalNumber++;
                        i++;
                        j++;
                        continue;
                    }
                    if(gameField.isX(i,j)) {
                        criticalNumber = 0;
                        break;
                    }
                    i++;
                    j++;

                }

            }
        }

        if (criticalNumber == gameField.getFieldSize() - 1) {
            return true;
        }
        return false;
    }