Concentration (card game)

Concentration can be played with any number of players or as a solitaire or patience game.

It is a particularly good game for young children, though adults may find it challenging and stimulating as well.

Standard rules need not be followed: the cards can be spread out anywhere, such as all around a room.

If they are not of the same rank and color, they are turned face down again and play passes to the player on the left.

Concentration may be played solo either as a leisurely exercise, or with the following scoring method: play as normal, but keep track of the number of non-matching pairs turned over (this may be done using poker chips, pennies or by making marks on a sheet of paper).

The object is to clear the tableau in the fewest turns, or to get the lowest possible score.

With perfect memorization and using an optimal strategy, the expected number of moves needed for a game with

It is common for many players to think they know where pairs are and to turn over the one they are sure of first, then be stumped finding its mate.

An ideal strategy can be developed if we assume that players have perfect memory.

In some computer versions, the cards may randomly move to increase the difficulty.