Editing Go professional (section)

==Pro and amateur dan==
In theory, professional dans should beat all levels of amateur dans. In reality, the very top amateurs have proven very able. The conventional wisdom is that such players may achieve some of the insight of a pro, though perhaps not the detailed knowledge.

In China, Korea, and Japan, there are two distinct ranking sets, one for amateur players and one for professional players (who receive a fee for each game they play, bonuses for winning, and fees for other related activities such as teaching).

In the Japanese professional ranking system, distinction between ranks was traditionally considered to be roughly one third of a handicap stone (making the difference 3 pro dan equal to one amateur dan). The strength of new professionals (1-dan) was usually comparable to that of the highest ranked amateurs. Currently the professional ranks are assumed to be more bunched together, covering not much more than two amateur dans; so that pro 1 dans win some games against 9 dans. There are also a number of amateur players acknowledged as having pro 6 dan understanding of the game.

In South Korea, there are several amateur systems in use, with the recent introduction of official 7-, 6- and 5-dan amateur ranks, each of which is somewhat stronger than the corresponding European grade. A 7-dan amateur will have won three national events, and will be effectively of lower-ranked pro standard. The older gup system does not easily match others. In practice, in Korean clubs, grades may be worked out against the resident strongest amateur.

The Taiwan Chi Yuan Culture Foundation also employs a dan system similar to that in Japan. It ranks its professional players from beginner dan (初段) up to 9-dan, being the highest.<ref>{{cite web
 |url         = http://taiwango.org.tw/info.asp
 |title       = List of professional players in Taiwan
 |url-status     = dead
 |archive-url  = https://web.archive.org/web/20070928224440/http://www.taiwango.org.tw/info.asp
 |archive-date = 2007-09-28
}}</ref>  However, the amateur ranking system is established by another organization which certifies amateur player through competitions, ranking player from beginner dan (初段) to 6-dan with 7-dan being honorary.<ref>{{cite web
 |url=http://www.weiqi.org.tw/default.asp 
 |title=Taiwan Go Association 
 |url-status=dead 
 |archive-url=https://web.archive.org/web/20070927015754/http://www.weiqi.org.tw/default.asp 
 |archive-date=2007-09-27 
}}</ref>

In Germany and the Netherlands a "classes"-system (German: "Klassen") was established by Go pioneer Bruno Rüger in 1920. It comprised a further subdivision into Kyu/Dan half-grades with classes 18 and 17 = amateur 1-dan with the 17 being on the stronger side. It was replaced by the Japanese amateur ranking system in the 1970s.