Scoring
At the end of a game of Go, assuming neither player has resigned first, a numeric score is determined for each player. The higher scoring player wins, after adjustment for komi. or the game may be tied (jigo). The numerical difference in score does not matter; a win is a win.
While Go is played basically the same world-wide, there are several different rulesets in use. One of the ways that rulesets differ is in scoring. Here we use scoring to refer to the definition of score. The point is to distinguish it from the actual procedure used to find the score, referred to as counting. This is a useful, if not universally followed, distinction. (Note, though, that counting has other usages as well, including counting during the game to see who's leading, generally known as positional judgment.)
There are two main scoring systems: Area scoring and Territory scoring. But which system is used will not normally affect who wins the game. And the difference between the scores will be zero or at most one point in the vast majority of games. Various counting methods can be used to find the score under each scoring system.
More information is available on the arcana of Territory and Area Scoring. The information below is meant as an overview.
Area Scoring
In area scoring, your score is:
- the number of empty points your stones surround, after removing any dead stones of your opponent's
- plus the number of your living stones on the board
Area scoring is used in certain rulesets, notably Chinese Rules and Ing Rules.
To determine the score with area scoring, Chinese counting is generally used. An alternative method is Ing counting.
Territory Scoring
In territory scoring, your score is:
- the number of empty points your stones surround, after removing any dead stones of your opponent's
- less the number of your stones that have been killed (whether captured during the game, or remaining on the board as dead stones at the end of the game)
Territory scoring is used in Japanese rules and Korean rules, and in several on-line servers.
To determine the score with territory scoring Japanese Counting is used.
Other Scoring Systems
There are a number of other scoring methods of historical and theoretical interest. In particular, Stone Scoring, used centuries ago in China, has a different scoring system.
There are some house rules in Go where losing by a landslide counts as more than one loss. A Korean version that I am aware of is called a Mahn Bang.
Although not a scoring issue per se, when gambling on games, the payoff may be defined as a multiple of the number of points the winner won by; this is called mego in Japanese.