This shows you the board positions after each move of the specified
game. If you are already observing the specified game, this will
remove it from your observation list. The game may be specified either
by its number or by the name of one of the players playing that game.
If no argument is specified, all observation is turned off.
You can observe a game while playing or examining.
You can observe up to 32 games simultaneously, if your client
is capable of it. You may need to do "set unobserve 0" in order
to watch more than one game at a time.
You can use the "follow" command to observe a certain player, and then
observe each new game he plays automatically, without having to type
"observe" for each game.
You can use the letter codes in help games2 to define which type
of game you want to watch.