A fourth umpire is required for all international matches to perform duties such as bringing on the new ball, carrying drinks onto the field for the umpires, checking the batteries in the light meter, observing the pitch during the lunch and tea intervals to ensure there is no interference, and bringing on new bails. In domestic cricket, a fourth umpire may be used in place of an eighth bowler.
The role was introduced into Test cricket in 1877 by the Australian Charles Bannerman, who felt that too many mistakes were made by the third umpire when he had only his fellow umpires to rely on for assistance. The practice has been retained even though not all countries are happy with it. In fact, several have gone so far as to say that it violates the spirit of the game.
India banned the use of fourth umpires in Test matches in 1994. However, they continue to use them in One Day Internationals and Twenty20 Internationals.
In Australia, the use of fourth umpires is permitted but not recommended. Their advice is given very carefully, since any error can lead to a loss of confidence in the system. However, since there are only three umpires in each team's box, there is always a fourth umpire available if needed.
In England, the use of fourth umpires is permitted but not recommended.
Their responsibility is to make the ultimate decision on matters submitted to them by the two on-field umpires or the players. If necessary, the third umpire can also serve as an emergency on-field umpire. They work in collaboration with the other two umpires.
They have the power to rule on any point that the on-field umpires cannot agree upon. This could be either because they disagree with their decisions or because they want further clarity on a particular matter. The third umpire can also change their mind at any time during the match and announce a different result than what was originally called. However, this should not happen too often or it may affect the credibility of the game's most important ruling system.
In case of a dispute between the on-field umpires, then the third umpire will always take charge and make the final call. This is because they are responsible for ensuring that all matches are played according to the rules and that no aspect of the game is overlooked. They do not want to see anything inappropriate taking place on the field while the match is being played.
The third umpire should be experienced and know how to write good reports. This is very important since they make rulings on close calls and sometimes even disputed incidents. Therefore, it helps if they are people who don't seem to make mistakes when making critical decisions.
There should be two umpires with particular roles for all games played in accordance with the regulations outlined in the Official Rounders' Rules Book. Outside of the playing season, in the fall or winter, credentials and practical experience can be earned in preparation for the next season. In the summer, new candidates can apply to become accredited by the ICC.
The number of umpires has varied over time because of changes to rules and technology. At one stage, it was common for there to be only one official umpire per side, but now each team usually has at least two. The number of umpires has also varied depending on how many men's international matches are being played in any given year. If more than eight men's tests are being held, then four additional umpires must be employed. If seven or more one-day internationals are taking place, then three more umpires need to be appointed.
In terms of numbers, nine is generally considered a minimum crew size for an effective umpire panel, but many countries have more than this. Australia had 13 umpires during their recent tour of India. England had 16 during their home series against Pakistan last year. New Zealand have used as many as five at once on several occasions.
The most experienced umpires tend to work the more important games, while younger ones get opportunities to officiate in lower-profile matches.