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.
Cricket has never stopped evolving: from round-arm bowling becoming the standard, to the 15-degree rule for arm flexion while bowling. From the number of balls per over to the specifications of equipment - ranging from glove-webbing to bat handles - almost every aspect of the game is regulated. New rules are frequently put in place - especially in the shorter forms of the game, as in the case of Powerplays, free hits, and the tweaking of field restrictions.
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.
For a game as steeped in tradition as cricket is, the question of how much to rely on technology is a perennial - and is now becoming increasingly complex. The Decision Review System has been controversial since it was first put in place
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
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.
In September 2010 the ICC suspended three Pakistan players - Mohammad Amir, Mohammad Asif and Salman Butt - on allegations of what was later defined as spot-fixing. They were alleged to have carried out specific on-field actions, including bowling no-balls at pre-determined times, during the Lord's Test against England on the instance of a bookie. The three were later handed long bans by the ICC before the matter moved to the British Crown courts, where all three were convicted and sentenced to spells of detention.
The attack on the Sri Lankan team bus in Lahore in March 2009 was the first time cricketers had been directly targeted by terrorists. That attack, in which several cricketers and coaching staff were injured, shattered the illusion that sportsmen were outside the terrorists' agenda. As the cricket world tried to digest the the story of Sri Lanka's miraculous escape, Pakistan sunk further into the abyss of isolation
The growth of Twenty20 cricket has raised serious questions over the utility of the 50-over game, and concerns for its future. Though it is still the currency of the two main ICC tournaments, some boards have already shortened their domestic format. Suggestions for change have been plenty and even the ICC is thinking about tweaking the format.
As the popularity of T20 cricket rises, administrators are striving to improve the following of Test cricket through innovations such as day-night fixtures. The inaugural day-night Test in Adelaide was a commercial success but some challenges remain, such as the quality of the pink ball, dew, and player scepticism