Before 1895, "first-class cricket" was a common term used loosely to suggest that a match had a high standard; adjectives like "great", "important" and "major" were also loosely applied to such matches. There was at the time no concept of what became Test cricket and so an international match would be called a first-class one, as would any match involving two senior county clubs. At the beginning of the 1860s, there were only four formally constituted county clubs: Sussex is the oldest, formed in 1839, and it had been followed by Kent, Nottinghamshire and Surrey. In the early 1860s, several more clubs were founded and questions began to be raised in the sporting press about which should be categorised as first-class, but there was considerable disagreement in the answers. In 1880, the Cricket Reporting Agency was founded. It acquired influence through the decade especially by association with Wisden Cricketers' Almanack (Wisden) and the press came to generally rely on its information and opinions.
The term acquired official status, though limited to matches in Great Britain, following a meeting at Lord's in May 1894 between the Marylebone Cricket Club (MCC) committee and the secretaries of the clubs involved in the official County Championship, which had begun in 1890. As a result, those clubs became first-class from 1895 along with MCC, Cambridge University, Oxford University, senior cricket touring teams (i.e., Australia and South Africa at that time) and other teams designated as such by MCC (e.g. North v South, Gentlemen v Players and occasional "elevens" which consisted of recognised first-class players). Officially, therefore, the inaugural first-class match was the opening game of the 1895 season between MCC and Nottinghamshire at Lord's on 1 and 2 May, MCC winning by 37 runs.
The term "first-class cricket" was formally defined by the then Imperial Cricket Conference (ICC) on 19 May 1947. It was made clear that the definition "will not have retrospective effect". The definition is as follows:
A match of three or more days' duration between two sides of eleven players officially adjudged first-class, shall be regarded as a first-class fixture. Matches in which either team have more than eleven players or which are scheduled for less than three days shall not be regarded as first-class. The Governing body in each country shall decide the status of teams.
For example, MCC was authorised to determine the status of matches played in Great Britain. For all intents and purposes, the 1947 ICC definition confirmed the 1894 MCC definition and gave it international recognition and usage.
Hence, official judgment of status is the responsibility of the governing body in each country that is a full member of the International Cricket Council (ICC). The governing body grants first-class status to international teams and to domestic teams that are representative of the country's highest playing standard. Later ICC rulings make it possible for international teams from associate members of the ICC to achieve first-class status but it is dependent on the status of their opponents in a given match.
According to the ICC definition, a match may be adjudged first-class if:
A Test match is a first-class match played between two ICC full member countries subject to their current status at the ICC and the application of ICC conditions when the match is played.
A peculiarity of the two-innings match is the follow-on law. If the team that batted second is 200 runs or more behind on first innings total, it may be required to bat again (i.e., to immediately "follow on" from its first innings rather than the innings alternating as they would normally) in the third innings of the match.
In 2010, the ICC published its Classification of Official Cricket which includes the criteria with which a match must comply to achieve a desired categorisation. In the section on first-class cricket, there is a list of the types of match that should qualify. It is important to note, given the differences in opinion about what constitutes a first-class match, that the ICC clearly stipulates that its match type list "is not exhaustive and is merely indicative of the matches which would fall into the first-class definition". For example, the list includes matches of recognised first-class teams versus international touring teams; and the leading domestic championships (using their then-current names) such as the County Championship, Sheffield Shield, Ranji Trophy, Vijay Hazare Trophy etc.
The absence of any ICC ruling about matches played before 1947 (or before 1895 in Great Britain) is problematic for those cricket statisticians who wish to categorise earlier matches in the same way. They have responded by compiling their own match lists and allocating a strictly unofficial first-class status to the matches they consider to have been of a high standard. It is therefore a matter of opinion only with no official support. Inevitable differences have arisen and there are variations in published cricket statistics.
A key issue for the statisticians is when first-class cricket for their purpose is deemed to have begun. Writing in 1951, Roy Webber argued that the majority of matches prior to 1864 (i.e., the year in which overarm bowling was legalised) "cannot be regarded as first-class" and their records are used "for their historical associations". This drew a line between what was important historically and what should form part of the statistical record. Hence, for pre-1895 (i.e., in Great Britain) cricket matches, "first-class" is essentially a statistical concept while the historical concept is broader and takes account of historical significance. Webber's rationale was that cricket was "generally weak before 1864" (there was a greater and increasingly more organised effort to promote county cricket from about that time) and match details were largely incomplete, especially bowling analyses, which hindered compilation of records. According to Webber's view, the inaugural first-class match should have been the opening game of the 1864 season between Cambridge University and MCC at Fenner's on 12 and 13 May, Cambridge winning by 6 wickets.
When the Association of Cricket Statisticians and Historians (ACS) published its Guide to First-Class Cricket Matches Played in the British Isles in 1982, it tentatively agreed with Webber's 1864 start date by saying that "the line between first-class and other matches becomes more easily discernible about that date". A year earlier, the ACS had published its Guide to Important Cricket Matches Played in the British Isles 1709 – 1863 in which it listed all the known matches during that period which it considered to have historical importance. Therefore, pre-1895 matches of a high standard are termed "important matches" and are the equivalent of first-class matches played since 1895. The ACS did stipulate that they had taken a more lenient view of importance regarding matches played in the 18th century than they did of matches played in the 19th century. As they explained, surviving details of 18th century matches are typically incomplete while there is a fairly comprehensive store of data about 19th century matches, certainly since 1825.
Subsequently, Webber's view has been challenged by those who suggest earlier dates for the commencement of "first-class statistics". Bill Frindall believed that 1815 should be the start to encompass the entire roundarm bowling phase of cricket's history. However, roundarm did not begin in earnest until 1827. In Frindall's view, the inaugural first-class match should have been the opening game of the 1815 season between MCC and Middlesex at Lord's on 31 May and 1 June, Middlesex winning by 16 runs. The most significant internet-based views are those of CricketArchive (CA) and ESPNcricinfo (CI), both of which hold that the earliest first-class match was Hampshire versus All-England at Broadhalfpenny Down on 24 and 25 June 1772. CA has numbered this match "f1" (i.e., first-class match number one) and CI as "First-Class # 1".
However commendable these views may be, they are not only unofficial but also entirely statistical. The 1772 match left a scorecard that is complete apart from the bowling analyses and so the data is sufficient for a statistical study, especially as the scorecard was itself the start of a trend and there are surviving scorecards from every season commencing 1772. The historical view centres on the historical significance of a match and its known contemporary importance measured by, as is often the case with early matches, the amount of money at stake. Other factors are the size of the crowd, if known, and the fact that a match was deemed notable enough to be reported in the press. The earliest match known to have been accorded superior status in a contemporary report (i.e., "a great match" in this case) and to have been played for a large sum of money was one in Sussex between two unnamed eleven-a-side teams contesting "fifty guineas apiece" in June 1697, a match of enormous historical significance but with no statistical data recorded.