TStrikeCatsControl = class(TControl)
  private
    FCorrectValue: Integer;
  public
    constructor Create(AOwner: TComponent); override;
  published
    property CorrectValue: Integer read FCorrectValue;
  end;
 
...
 
constructor TStrikeCatsControl.Create(AOwner: TComponent);
begin
  inherited;
  FCorrectValue := Screen.DesktopWidth div 2;
end;