Not enough sleep or disruptions to the sleep-wake cycle (such as those that may occur with shift work or travelling to a different time zone) cause the physiological state known as fatigue. Staying awake for 24 hours leads to a reduced hand-to-eye coordination that is similar to having a blood alcohol content of 0.1.
There are 13 hearts in a standard 52 card deck. There are also 13 diamonds, 13 spades and 13 clubs.
The aggregate total of all scores for each hand must be a multiple of 26. The game is usually played to 100 points (some play to 50). When a player takes all 13 hearts and the queen of spades in one hand, instead of losing 26 points, that player scores zero and each of his opponents score an additional 26 points.