Editing Go (game) (section)

=== Tournament and match rules ===
{{See also|Go competitions}}
Tournament and match rules deal with factors that may influence the game but are not part of the actual rules of play. Such rules may differ between events. Rules that influence the game include: the setting of compensation points ([[komidashi|komi]]), handicap, and time control parameters. Rules that do not generally influence the game are the tournament system, pairing strategies, and placement criteria.

Common tournament systems used in Go include the [[Swiss system tournament#McMahon system|McMahon system]],<ref>{{Citation|url=https://www.britgo.org/organisers/mcmahon.html |publisher=British Go Association |title=The McMahon system in a nutshell |access-date=2008-06-11 |archive-url=https://web.archive.org/web/20080518202147/http://www.britgo.org/organisers/mcmahon.html |archive-date=2008-05-18 |url-status=dead}}</ref> [[Swiss system tournament|Swiss system]], [[league system]]s and the [[Single-elimination tournament|knockout system]]. Tournaments may combine multiple systems; many [[List of professional Go tournaments|professional Go tournaments]] use a combination of the league and knockout systems.<ref>{{harvnb|Fairbairn|Hall|2007|loc=''A quick guide to pro tournaments''}}{{page needed|date=May 2014}}</ref>

Tournament rules may also set the following:
* compensation points, called komi, which compensate the second player for the first move advantage of their opponent; tournaments commonly use a compensation in the range of 5–8 points,<ref name=histKomi>{{harvnb|Fairbairn|Hall|2007|loc=''History and Timelines'' "History of Komi"}}{{page needed|date=May 2014}}</ref> generally including a half-point to prevent draws;
* handicap stones placed on the board before alternate play, allowing players of different strengths to play competitively (see [[Go handicap]] for more information); and
* ''superko'': Although the basic ko rule described above covers more than 95% of all cycles occurring in games,<ref name="KoRules">{{Citation | title = Ko Rules | url = http://home.snafu.de/jasiek/korules.html | first = Robert | last = Jasiek | year = 2001 | access-date = 2007-11-30}}</ref> there are some complex situations—[[Ko fight#Complex situations involving ko|triple ko]], ''eternal life'',{{efn|1=A full explanation of the eternal life position can be found on [http://senseis.xmp.net/?EternalLife Sensei's Library], it also appears in the official text for Japanese Rules, see [http://www-2.cs.cmu.edu/~wjh/go/rules/Japanese.html translation].}} etc.—that are not covered by it but would allow the game to cycle indefinitely. To prevent this, the ko rule is sometimes extended to forbid the repetition of ''any'' previous position. This extension is called superko.<ref name="KoRules" />