The Association of Cricket Statisticians and Historians  The Association of Cricket Statisticians and Historians (ACS) was founded in England in 1973 for the purpose of researching and collating information about the history and statistics of cricket. Originally called the Association of Cricket Statisticians, the words "and Historians" were added in 1992 but it has continued to use the initialism ACS. The ACS headquarters were formerly in Nottingham, opposite Trent Bridge Cricket Ground, but relocated to Cardiff in 2006. Although constituted in England, the ACS has a worldwide membership and is open to anyone with a relevant interest. The membership in 2017 numbered around 1,000. Following the formal definition of first-class cricket by the then Imperial Cricket Conference (ICC) in May 1947, and particularly given ICC's statement that "the definition does not have retrospective effect", a number of cricket statisticians became interested in developing an agreed list of matches played before 1947 from which to compile accurate first-class records. Roy Webber published his "Playfair Book of Cricket Records" in 1951 and stated his view that first-class cricket records (i.e., for statistical purposes) should not include matches played before 1864. In this first edition, Webber accepted the records used by "Wisden Cricketers' Almanack", including those that summarised the career of W G Grace. In his second edition (1961), Webber challenged many existing views about match status and produced, "inter alia", an alternative career record for Grace that did not include some of the matches "Wisden" recognises as first-class. There was some support among cricket statisticians, including Bill Frindall, for Webber's basic arguments but there were (and remain) differences of opinion about his commencement date and about the details of his recommended matchlist. The controversial cricket historian Rowland Bowen wrote a lengthy critique of Webber's sources in 1961. Bowen then started "Cricket Quarterly" (1963–70), devoted to cricket statistics, which included among its contributors some of the original ACS members. The ACS itself was founded by Robert Brooke and Dennis Lambert, two of Bowen's contributors, by means of advertisements in the October 1972 issues of "The Cricketer" and "Playfair Cricket Monthly". These attracted a nucleus of some 50 members who formed the association in 1973. The ACS has sought to compile details of all known historically significant matches and has widened its scope to include details of other competitions such as the Minor Counties Cricket Championship and the Second XI Championship in England.