Drugs

Shane Warne's one-year ban for the use of a diuretic in 2003 was the first reported instance in cricket of the use of performance-enhancing drugs (as opposed to recreational ones, a la Ian Botham, and various Pakistani and South African cricketers down the years). In 2006 Shoaib Akhtar and Mohammad Asif were found guilty of using the banned steroid nandrolone

Jun 3, 2017: 'ICC should have had blood-testing long ago' | May 7, 2014: Kashif Siddiq banned for failing dope test

Corruption in cricket

Cricket's biggest match-fixing scandal was unearthed in 2000, when Hansie Cronje admitted he had accepted money to throw matches. Soon players from other countries were implicated, among them Mohammad Azharuddin and Saleem Malik. Since then, allegations of fixing - including the new phenomenon of spot-fixing - have cropped up sporadically, and it has been acknowledged that bookmakers and the underworld have been active in trying to influence cricket results and specific moments in play. In 2010, scandal reared its head again when three leading Pakistan players were questioned by Scotland Yard and suspended by the ICC over spot-fixing charges.

May 17, 2017: Mohammad Nawaz given two-month suspension | May 17, 2017: Nasir Jamshed threatens PCB with legal action

Pitches

Over the years the endeavour has been to take pitches out of the equation for ODIs and Twenty20s, by making them flat and uniform, so that the toss does not play a crucial part in the shorter format. In Tests, though, the preparation of the pitch and its durability are much more significant, impacting the result and duration of the game. Quite naturally pitches and their preparation in the longer forms of the game evoke a lot of comment and often controversy.

Mar 31, 2017: The pitches in India were great. Won't you agree, Australia? | May 26, 2017: Hard, flat and true

Player contracts

As cricketers became more aware of their rights and the money they earned their boards, every team gradually moved to the contracts system, which would assure a player a certain amount of income for a year irrespective of an injury or an unforeseen drop in form. There has been a fair amount of controversy over the implementation of contract systems over the years: the ugliest it got was when several West Indies stars refused to play for their team because of a dispute over contracts. India, Zimbabwe and Kenya have had their share of contracts-related problems too.

Mar 21, 2017: Player payment model outdated, says James Sutherland | Apr 20, 2017: What's wrong with revenue-sharing, CA?

Sledging

From WG Grace, with his penchant for delivering a running commentary on opposition players and umpires, to Steve Waugh's Australians and their tactic of "mental disintegration", sledging is almost as old as cricket itself. The Australians, from Dennis Lillee to Merv Hughes have been the acknowledged masters, but Asian exponents like Kumar Sangakkara are fast catching up

Feb 11, 2017: The case for sledging | Feb 23, 2017: Why we need needle

Chucking

Controversy over illegitimate bowling actions - a burning issue in the 1950s - flared up again in the mid-to-late-1990s after Muttiah Muralitharan was no-balled repeatedly in Australia. Since then a number of bowlers (Shoaib Akhtar, Shoaib Malik, Harbhajan Singh and Jermaine Lawson prominent among them) have undergone remedial work after having their actions reported.

Jan 30, 2017: An arm sleeve that tells you if you're chucking | Jan 19, 2016: Engelbrecht's reworked action deemed legal

Kolpak

A 2003 European Union ruling on the right of a Slovakian handball player to play in Germany has had a massive impact on English county cricket. It created an opening for players from countries with trade agreements with the EU (in effect South Africa, Zimbabwe and some Caribbean countries) to bypass the limits on overseas players and sign for counties. A trickle became a flood, and by 2008 there were more than 60 Kolpak cricketers in England, causing debate and acrimony between counties with arguments that their presence weakened English cricket. Click here for a more in-depth explanation.

Jan 9, 2017: Kolpak-alypse now? | Jan 9, 2017: South African cricket review highlights player loss

Ball-tampering

Players are barred, by Law 42.3, from rubbing the ball on the ground, interfering with its seam or surface, or using any implement that can alter the condition of the ball to thereby gain unfair advantage. There have been plenty of ugly incidents centring on accusations of ball-tampering through cricket's history: the John Lever "Vaseline" affair in 1976-77; the times England and New Zealand accused Pakistan of it in the early 1990s; Michael Atherton's admission that he used dirt to treat the ball against South Africa in 1994; and perhaps most infamously, the Oval Test of 2006 when Pakistan forfeited the match because they were accused of having tampered with the ball.

Jan 2, 2017: Margins, morality, and the many collapses of 2016 | Apr 6, 2017: Hell for leather