Short game

In CGT, a short game is an abstract game with only finitely many positions, while a long game has infinitely many.

Note that this is not equivalent to the requirement that play cannot continue indefinitely, which is usually stipulated in CGT (unless we are treating loopy games with cycles such as ko). Of course all small games terminate after a finite number of moves[1] but, for example, the game omega={0,1,2,3,cdots|} is not small, even though all Left’s options move to positions which are small.

The restriction to short games is necessary for various parts of the theory, in particular as it is applied to go. Go is of course a very short game, since the board permits a mere 3^(19*19)=
17","408","965","065","903","192","790","718","823","807","056","436","794","660","272","495","026","354","119","482","811","870","680","105","167","618","464","984","116","279","288","988","714","938","612","096","988","816","320","780","613","754","987","181","355","093","129","514","803","369","660","572","893","075","468","180","597","603 positions, of which only 208","168","199","381","979","984","699","478","633","344","862","770","286","522","453","884","530","548","425","639","456","820","927","419","612","738","015","378","525","648","451","698","519","643","907","259","916","015","628","128","546","089","888","314","427","129","715","319","317","557","736","620","397","247","064","840","935 are legal positions.