In English and Welsh cricket, the annual County Championship is the oldest and most prestigious domestic tournament and is played under first-class rules with matches scheduled for up to four days. Eighteen county clubs are involved and, since 2000, have been divided into two divisions with the title awarded at the end of each season to the team finishing top of the first division. There is promotion and relegation between the two divisions each season. The championship has tentative origins stretching back to the 1720s but on the basis of "bragging rights" only and the title did not really become authentic until the 1860s. In 1873, a residential qualification was imposed on players taking part in inter-county matches and so the title was effectively formalised from that season, though still without official sanction.
The tournament was re-launched on an official basis in 1890 when nine county clubs were involved. Five expansion clubs were invited to join in 1895 and there have been four more over the following century, the most recent being Durham in 1992. The most successful team has been Yorkshire who have won the title a record 32 times, plus one shared title, between 1893 and 2015.[1]