A Twenty20 International (T20I) is a form of cricket, played between two of the top members of the International Cricket Council (ICC), in which each team faces 20 overs. The matches have top-class status and are the highest T20 standard. The game is played under the rules of Twenty20 cricket. ICC decided to use DRS in Twenty20 internationals from October 2017.
The shortened format was initially introduced to bolster crowds for the domestic game, and was not intended to be played internationally, but the first Twenty20 International took place on 17 February 2005 when Australia defeated New Zealand, and the first tournament was played two years later, with the introduction of the ICC World Twenty20. In 2016, for the first time in a calendar year, more Twenty20 International matches(100) were played than ODI matches(99). There remain limits on how many Twenty20 Internationals a team can play each year, in order to protect Test cricket and One Day Internationals. As of 2016, there are 18 nations that feature in ICC T20I team rankings.
The shorter format of the game makes reaching the traditional milestones of scoring a century or taking five wickets in an innings more difficult, and few players have achieved these. The highest individual score in a Twenty20 International is 156, made by Australia's Aaron Finch against England in 2013, while Sri Lanka's Ajantha Mendis is the only bowler to have taken two six wickets in an innings, and fewer than twenty players have taken five wickets in an innings.
Cricket itself was probably first played in England in the Late Middle Ages, but it did not rise to prominence until the eighteenth century. A set of laws were drawn up in 1744, and the game achieved a level of relative standardisation by the late nineteenth century.One-day cricket was trialled in 1962, and the first domestic tournament played the following year, and in 1971, England and Australia contested the first One Day International. The match consisted of one innings for each side, with 40 eight-ball overs.