Card reading (bridge)
In contract bridge, card reading (or counting the hand) is the process of inferring which remaining cards are held by each opponent. The reading is based on information gained in the bidding and the play to previous tricks. The technique is used by the declarer and defenders primarily to determine the probable suit distribution and card holdings of each unseen ; determination of the location of specific spot-cards may be critical as well. Card reading is based on the fact that there are thirteen cards in each of four suits and thirteen cards in each of four  hands. General tips. Basic. There are some basic tips: Advanced. The advanced tips include: Counting suits. Counting trumps. As a declarer, an efficient way of counting the trump cards is: instead of counting the number of trump rounds and cards trumped in, "count the number of trumps in the opponents' hands". Once the dummy hand appears, calculate the number of trumps which the opponents have, then reduce this number mentally as they are played from the opponents' hands. This means keeping track of one small number, and your own trumps do not enter the calculation. An even better way of  counting trumps is to get familiar with common distribution patterns. For example, 5-3 and 4-4 are among the most common trump distributions on the declarer and dummy's hands. In cases, if an opponent shows out on the second trump round, then 5-3-1 or 4-4-1 is known, and the pattern 5-3-4-1 or 4-4-4-1 comes up automatically, and the other defender is known to have begun with four.