A bowler reaches his delivery stride by means of a "run-up" and an over is deemed to have begun when the bowler starts his run-up for the first delivery of that over, the ball then being "in play". Fast bowlers, needing momentum, take a lengthy run up while bowlers with a slow delivery take no more than a couple of steps before bowling. The fastest bowlers can deliver the ball at a speed of over 145 kilometres per hour (90 mph) and they sometimes rely on sheer speed to try to defeat the batsman, who is forced to react very quickly. Other fast bowlers rely on a mixture of speed and guile by making the ball seam or swing (i.e. curve) in flight. This type of delivery can deceive a batsman into miscuing his shot, for example, so that the ball just touches the edge of the bat and can then be "caught behind" by the wicket-keeper or a slip fielder. At the other end of the bowling scale is the spin bowler who bowls at a relatively slow pace and relies entirely on guile to deceive the batsman. A spinner will often "buy his wicket" by "tossing one up" (in a slower, steeper parabolic path) to lure the batsman into making a poor shot. The batsman has to be very wary of such deliveries as they are often "flighted" or spun so that the ball will not behave quite as he expects and he could be "trapped" into getting himself out. In between the pacemen and the spinners are the medium paced seamers who rely on persistent accuracy to try to contain the rate of scoring and wear down the batsman's concentration.
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).
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".