The batsman on strike (i.e. the "striker") must prevent the ball hitting the wicket, and try to score runs by hitting the ball with his bat so that he and his partner have time to run from one end of the pitch to the other before the fielding side can return the ball. To register a run, both runners must touch the ground behind the popping crease with either their bats or their bodies (the batsmen carry their bats as they run). Each completed run increments the score of both the team and the striker.
Cricket is one of many games in the "club ball" sphere that basically involve hitting a ball with a hand-held implement; others include baseball, golf, hockey, tennis, squash, badminton and table tennis. In cricket's case, a key difference is the existence of a solid target structure, the wicket (originally, it is thought, a "wicket gate" through which sheep were herded), that the batsman must defend. The cricket historian Harry Altham identified three "groups" of "club ball" games: the "hockey group", in which the ball is driven to and fro between two targets (the goals); the "golf group", in which the ball is driven towards an undefended target (the hole); and the "cricket group", in which "the ball is aimed at a mark (the wicket) and driven away from it".
The decision to attempt a run is ideally made by the batsman who has the better view of the ball's progress, and this is communicated by calling: usually "yes", "no" or "wait". More than one run can be scored from a single hit: hits worth one to three runs are common, but the size of the field is such that it is usually difficult to run four or more. To compensate for this, hits that reach the boundary of the field are automatically awarded four runs if the ball touches the ground en route to the boundary or six runs if the ball clears the boundary without touching the ground within the boundary. In these cases the batsmen do not need to run. Hits for five are unusual and generally rely on the help of "overthrows" by a fielder returning the ball. If an odd number of runs is scored by the striker, the two batsmen have changed ends, and the one who was non-striker is now the striker. Only the striker can score individual runs, but all runs are added to the team's total.
During normal play, thirteen players and two umpires are on the field. Two of the players are batsmen and the rest are all eleven members of the fielding team. The other nine players in the batting team are off the field in the pavilion. The image with overlay below shows what is happening when a ball is being bowled and which of the personnel are on or close to the pitch.
^ His Hall of Fame plaque states, in part: "Inventor of the box score. Author of the first rule-book ... Chairman of rules committee in first nationwide baseball organization." Lederer, Rich. By the Numbers: Computer technology has deepened fans' passion with the game's statistics. Memories and Dreams (Vol. 33, No. 6; Winter 2011[–2012], pp. 32–34). National Baseball Hall of Fame official magazine.
The entomopathogenic fungus Metarhizium anisopliae attacks and kills crickets and has been used as the basis of control in pest populations. The insects are also affected by the cricket paralysis virus, which has caused high levels of fatalities in cricket-rearing facilities. Other fatal diseases that have been identified in mass-rearing establishments include Rickettsia and three further viruses. The diseases may spread more rapidly if the crickets become cannibalistic and eat the corpses.