I once played the following game:
I just wanted to see if I could embed a game posted ChessTheatre inside Joomla! This is done as follows: create a new article, type your text and at the wanted position insert embedded media. Choose for flash and copy the URL: https://www.chesstheatre.com/chesstheatre_gui.swf?xml=http%3A%2F%2Fwww.chesstheatre.com%2Fgame.php%3Fbi%3D249 where you have to replace the last three digits (249) for the number of the game you want to show. You can find this number by find the same string in the source of the ChessTheatre page, search for 'game.php'.