|Administrator||New Zealand Cricket|
|Number of teams||6|
|Current champion||Central Districts|
|Most runs||Craig Cumming (6,589)|
|Most wickets||Stephen Boock (399)|
The competition was instigated in October 1906 with the donation of a shield by William Plunket, 5th Baron Plunket, the Governor-General of New Zealand. For the 1906-07 inaugural season, the Shield was allotted by the New Zealand Cricket Council "to the Association whose representative team it considers to have the best record for the season". After the Council awarded the Shield to Canterbury, chiefly because Canterbury were the only provincial team to beat the visiting MCC, Auckland representatives complained that Auckland should have received the Shield as their team was superior but had not had the chance to prove it as none of the other provincial teams had played Auckland during the season.
Beginning with the 1907-08 season, the competition was decided by challenge matches among Auckland, Wellington, Canterbury, Otago and, on two occasions, Hawke's Bay. Auckland defeated Canterbury by an innings in the first challenge match in December 1907.
A proposal in 1912 that the Shield should be decided by an inter-provincial tournament rather than by the challenge system was rejected as impracticable at the time. However, starting with the 1921–22 season, the four principal teams (minus Hawke's Bay, which lost first-class status) played each other in a single round-robin series of matches. Central Districts entered the competition in 1950–51, and Northern Districts in 1956–57.
Shell Oil became principal sponsor in 1974–75 and a new trophy was introduced. Games were played over three days during this period, with an over-limit on the first innings. In latter years the format was experimented with, introducing a shorter second round, various bonus points systems, and eventually a knockout final.
The format and the principal sponsor were changed in 2001–02 season. State Insurance (more commonly just called 'State') replaced Shell Oil. The competitions were renamed to reflect the new sponsor's name, so despite the fact that New Zealand does not have political 'states', the correct name for the first-class competition was the 'State Championship'. Each of the provincial teams played in a single round-robin series of four-day matches. There was a target of 112 overs in each day's play. After the round-robin the two highest-ranked teams played a five-day final.
A List A 50-over competition known as the State Shield was run from late December to the end of January, culminating with a semi-final (second versus third) and final (the semi-final winner against the top qualifier) early in February.
In 2006, a provincial Twenty20 competition was begun, and was played during February and early March. The top two sides qualified for the final. It was called the State Twenty20.
Plunket Shield reinstatedEdit
With State Insurance withdrawing from their sponsorship, the Plunket Shield was reinstated for the 2009–10 season. New Zealand Cricket has stated that the naming rights are no longer for sale and that the name Plunket Shield will remain. The final has also been abolished, meaning that the champion of the competition will be determined by the points leader at the end of the double round robin.
(counted since 1921–22 season)
|Canterbury (Canterbury/West Coast)||1906/07||2016/17||19|
|Central Districts (Hawke's Bay/Taranaki/Manawatu/Nelson/Marlborough)||1950/51||2018/19||11|
|Northern Districts (Northland/Bay of Plenty/Waikato/Gisborne)||1956/57||2011/12||8|
Hawke's Bay played twice in the Plunket Shield, in the 1914/15 and 1920/21 seasons, losing both matches.
Points are awarded at the conclusion of each match during the season. With no final, the team with the most points is declared the champion. The points system for the 2019/20 season is as follows
- Won: 12 points
- Lost: 0 points
- Draw: 0 points
- Tie: 6 points
- One-innings match won (match that started with 10 hours or less playing time remaining): 6 points
- One-innings match tie: 3 points
- Abandoned (without a ball bowled) / No result (drawn one-innings match): 2 points
- Batting points: First Innings only up to 110 overs – first point at 200 runs, second point at 250 runs, third point at 300 runs, fourth point at 350 runs
- Bowling points: First Innings only up to 110 overs – first point at 3 wickets, second point at 5 wickets, third point at 7 wickets, fourth point at 9 wickets
The holders of the shield during its "challenge match" period to 1921 were:
|1915–18||no competition due to World War I||–|
From the 1921–22 season the competition has been run on a round robin format.
|1940–45||(not contested due to World War II)|
|1991–92||Central Districts & Northern Districts|
|2011–12||Northern Districts||Central Districts|
- "Plunket Shield returns as premier domestic first-class trophy". New Zealand Cricket. Retrieved 20 June 2010.
- "Obituaries in 1920". ESPN Cricinfo. Retrieved 27 October 2019.
- "New Zealand Council". Press. LXII (12638): 2. 31 October 1906. Retrieved 10 January 2018.
- "Notes by Long Slip". Otago Witness (2775): 57. 22 May 1907. Retrieved 10 January 2018.
- R.T. Brittenden, Great Days in New Zealand Cricket, A.H. & A.W. Reed, Wellington, 1958, pp. 33–38.
- "Revision of Plunket Shield Matches". Evening Post. 84 (9): 2. 10 July 1912. Retrieved 22 March 2017.
- "New Zealand bring back Plunket Shield". Cricinfo.com. 4 November 2009.