In the photo, the two batsmen (3 & 8; wearing yellow) have taken position at each end of the pitch (6). Three members of the fielding team (4, 10 & 11; wearing dark blue) are in shot. One of the two umpires (1; wearing white hat) is stationed behind the wicket (2) at the bowler's (4) end of the pitch. The bowler (4) is bowling the ball (5) from his end of the pitch to the batsman (8) at the other end who is called the "striker". The other batsman (3) at the bowling end is called the "non-striker". The wicket-keeper (10), who is a specialist, is positioned behind the striker's wicket (9) and behind him stands one of the fielders in a position called "first slip" (11). While the bowler and the first slip are wearing conventional kit only, the two batsmen and the wicket-keeper are wearing protective gear including safety helmets, padded gloves and leg guards (pads).
There are various formats ranging from Twenty20, played over a few hours with each team batting for a single innings of 20 overs, to Test matches, played over five days with unlimited overs and the teams each batting for two innings of unlimited length. Traditionally cricketers play in all-white kit, but in limited overs cricket they wear club or team colours. In addition to the basic kit, some players wear protective gear to prevent injury caused by the ball, which is a hard, solid spheroid made of compressed leather with a slightly raised sewn seam enclosing a cork core which is layered with tightly wound string.
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.
Single wicket was popular in the 18th and 19th centuries and its matches were generally considered top-class. In this form, although each team may have from one to six players, there is only one batsman in at a time and he must face every delivery bowled while his innings lasts. Single wicket has rarely been played since limited overs cricket began. Matches tended to have two innings per team like a full first-class one and they could end in a draw.
Limited overs cricket is always scheduled for completion in a single day. There are two types: List A which normally allows fifty overs per team; and Twenty20 in which the teams have twenty overs each. Both of the limited overs forms are played internationally as Limited Overs Internationals (LOI) and Twenty20 Internationals (T20I). List A was introduced in England in the 1963 season as a knockout cup contested by the first-class county clubs. In 1969, a national league competition was established. The concept was gradually introduced to the other leading cricket countries and the first limited overs international was played in 1971. In 1975, the first Cricket World Cup took place in England. Twenty20 is a new variant of limited overs itself with the purpose being to complete the match within about three hours, usually in an evening session. The first Twenty20 World Championship was held in 2007. Limited overs matches cannot be drawn, although a tie is possible and an unfinished match is a "no result".