Editing Go professional (section)

==Discrepancies among professionals==
The strength differences between professional levels is usually considered to be no more than 2–3 handicap stones. Therefore, the difference between professional dan levels corresponds to about one-third to one-fourth of a handicap stone.

Each country has different rules for promotion. Ranks may, therefore, differ somewhat from country to country.

Professionals may also differ in actual strength for a number of reasons, such as promotion not keeping up with actual gains in strength, or the fact that professional ranks (unlike kyu or amateur dan) may rise, but never fall (even if the player grows weaker). This has posed some problems, esp. with regards to international rank discernment. There are currently over one hundred people who have the rank of 9p (the highest professional rank), though many of them no longer play competitively.{{Citation needed|date=December 2010}} A further distinction is that some 9p players regularly hold titles, others won some titles, some entered the title leagues, and many 9p never had the fortune to achieve any of the above.

Traditionally it has been uncommon for a low professional dan to beat some of the highest pro dans. But since the late-1990s it has slowly become more common. This trend has been primarily credited to the result of increased competition to become a professional player in China and Korea. The result, that new ''1-dan'' professionals are generally stronger than other ''1 dans'' in the past.

In Japan, the ''[[Oteai]]'' system was reformed in 2004. The goal was to help alleviate some of the rank inflation that had crept in over the years. Today's Japanese system uses various benchmarks; for example, winning certain tournaments or a certain number of games, to be promoted by a rank. The Korean and Chinese systems have also been similarly changed in the past several years. These systems have increased the importance of international tournaments by incentivising rank promotion through international placement. Recent criticism has been given to this aspect, arguing that an individual may increase many professional ranks at once through the virtue of a single competition result (such as [[Piao Wenyao]]).