Editing Handicapping in Go (section)

==Handicap stones==
The rank difference within a given amateur ranking system is one guide to how many handicap stones should be given to make the game a more equal contest. As a general rule, each rank represents the value of one stone. (In terms of points, one stone is considered to be 13-16 points, but this figure is not constant over levels: the more skillful a player, the greater the usefulness of each stone.)

For example, a 3 ''kyu'' player gives a  7 ''kyu'' player four handicap stones to allow for an interesting game with roughly equal challenge for both players. If traditional fixed placement of the handicap stones is used, nine stones is normally the maximum handicap. Larger handicaps are certainly possible; but with such a great difference in strength, Black may be simply bewildered, and not understand how many of White's moves relate to his own.

The above rank relationship reliably applies for single-digit ''kyu'' (1-9k) and amateur ''dan'' (1-7d) ranks. The advantage of moving first is equivalent to only half a stone of handicap, as the opponent then has the initiative.  Because White gets the next move after Black places the handicap stones, a nominal handicap of ''n'' stones is therefore in reality half a stone less than ''n''.

Nowadays professional ranks are awarded by professional Go players' organizations; they are, unlike amateur ranks, not reliable as a measure of current playing strength, but rather an indication of achievements. Before the late 20th century, they were used as strength measurement, with a difference in skill of less than a third of a stone per rank.