Komi (Go)
Standard is 6.5 points under the Japanese and Korean rules; under Chinese, Ing and AGA rules standard is 7.5 points; under New Zealand rules standard is 7 points. typically applies only to games where both players are evenly ranked. In the case of a one-rank difference, the stronger player will typically play with the white stones and players often agree on a simple 0.5-point to break a tie () in favour of white, or no at all. is the more complete Japanese language term. The Chinese term is 贴目 (tiē mù) and the Korean term is Deom  (). Efforts have been made to determine the value of for boards much smaller than the standard 19x19 grid for go, such as 7x7. When introducing Environmental Go, Elwyn Berlekamp made a broad generalisation of to illustrate the practical value of the temperature concept from combinatorial game theory. Whole number and halves. Conventional "komi" in most competitions is a half-integer such as 6.5 points. This is convenient and the prevailing usage for knock-out tournaments, since it makes a tied game ("jigo" in Japanese) and rematches less likely (a drawn game is still possible under Japanese rules since the Japanese  rule prohibiting repeated positions applies only to the simplest possibility, called 'ko'). In a club or friendly game this is not a problem, so a value such as 6 points is just as practical. Within a Swiss system draw, tied games are not inconvenient and tiebreakers are used. Some argue there is nothing wrong in having a tie. Forbidding a draw may misrepresent one player as superior when there is no difference in skill. History. White is at a disadvantage because Black gets to move first, giving that player sente ("initiative"). Records show that the winning percentage of Black is  higher. The importance of playing first was, however, not dealt with by the rules until the 1920s, and then only tentatively. The compensation ("komi") system was introduced into professional Go in Japan as a gradual process of innovation, beginning in the 1920s. The , a Go organization established in 1922 and dissolved with the formation of the Nihon Ki-in in 1924, used a 4.5 point komi among its many rule innovations. The correct value of "komi" has been re-evaluated over the years, as professional opening strategy has evolved. At first, komi could be as low as 2.5 points or  3 points. It was later increased to 4.5, and then 5.5 points. A komi of 5.5 points was used for a long time, but research found that 5.5 points was insufficient to compensate for White's disadvantage. Statistical analyses of the year's games would sometimes appear in the "Igo Nenkan" ("Kido Yearbook"), backing up the intuition of many top players. The use of databases confirmed figures such as 53% victories for Black, not just at the highest level. "Komi" was then raised to 6.5. Some events use as high as 7.5 points. Under the Chinese method of counting, the  difference between 5.5 and 6.5 points is of minimal effect. Chinese sources usually in fact quote figures that are halved, such as 2.75 for 5.5, at least for Chinese domestic competitions, as one "stone" (the scoring increment typically used in China) is equivalent to two "points". Handicap games are almost universally played with a komi of 0.5 points. The advantage of playing one or more black stones (the number usually calculated as the difference in player's rank) before the white player's first move constitutes the remainder of the handicap, with the 0.5 komi determining white as winner in  games that would otherwise be a draw. John Fairbairn, a Go historian, has written on the history of "komi". In his 1977 "Introduction to Go" he stated that the value was about 5. Effects on strategy. Since very minor mistakes can cost one point, discussion of the 'true' value for "komi" makes little sense, except at the level of the top-ranked players in the world. These are (in most cases) also the opening-theory experts, and evaluate opening strategies in practical play against their peers. The introduction and then increase of "komi" has led to ever more ambitious or  aggressive strategies for Black, the first player. In the days before "komi", White as second player had to disrupt the smooth working of Black's classical strategies, described sometimes as aiming for a sure win by 3 points. From the introduction of "komi" in most pro events, around 1950, Black's older methods had to be reconsidered, since White suddenly needed appreciably less (in pro terms) in secure area. The 3-3 point became an interesting play for White, where previously it appeared experimental, and was developed in particular by Go Seigen and Sakata Eio. In the following decades a  mixture of classical and "shinfuseki" techniques became normal. The most obvious effect was the replacement of the 4-3 point by the 4-4 point as the most common way to first occupy a corner. Perfect Komi. In theory a perfect value of Komi would make each game result in Jigo (draw) given perfect play by both sides. Since in practice no human or computer can play perfect Go, this value is not known with certainty. However under area scoring rules and in the absence of Seki the perfect Komi can be shown to be an odd integer and statistics  from professional and computer play suggest that 7 is the correct value. Local variations. Although 6.5 points is a common komi as of 2007; each country, association, and tournament may set its own specific komi: Types. Fixed compensation point system. By far the most common type of "komi" is a fixed compensation point system. A fixed number of points, determined by the Go organization or the tournament director, is given to the second player (White) in an even game (without handicaps) to make up for first-player (Black) advantage. Auction komi. As no one can be absolutely sure of the  ideal value for komi, systems without fixed komi are used in some amateur matches and tournaments. This is called auction komi. Examples of auction komi systems: OR