backGoBase.org Fujitsu, Ltd. index | rules of go
Go, an addictive game Copyright © 1994-2014 GoBase
studying go | rules  

5.3 The Preliminary End of the Game

Making the neutral points truly neutral means that the first pass can be made regardless of the number of neutral points. In area rules III the first pass has to be made when the number of neutral points is even, because a player loses a point if he passes when the number is odd. At the same time, since the term (n1 - n2) affects the score, both players compete to be first to pass.

In the equations defining s1 and s2, every stone played after the last competitive move increases the term (N1 - n1) or (N2 - n2) by one. Stones played inside one's own territory do not change the score, the one-point reduction being balanced by the one-point gain, but each stone played on a neutral point increases the score by one. So if the last competitive move occurs when there are an odd number of neutral points, the first player to play after the last competitive move gains a point.

Let's call the time at which the players start scoring points for moves the "preliminary end" of the game. If we want to let the first pass be made regardless of the number of neutral points, when a player makes the first pass, his opponent must have the right to decide whether this is the preliminary end. This leads us to define the preliminary end by means of consecutive passes.

If the first pass is made when there are an even number of neutral points, and if the next player also passes, then the game reaches its preliminary end with an even number of neutral points left. If the next player does not pass but occupies one of the neutral points, his opponent will also occupy a neutral point instead of passing. The preliminary end will not occur when the number of neutral points is odd.

If the first pass is made when there are an odd number of neutral points, the next player should occupy one of the neutral points, because passing and causing the preliminary end of the game would lose a point. In any case, the player who makes the second consecutive pass always has the right to do so when there are an even number of neutral points left.

For this reason, territory rules cannot carry on from a single pass into the second phase as in area rules III. This is why the rule about the preliminary end is necessary. As a result of this rule, playing on neutral points before the preliminary end of the game never leads to profit.

Note that with both area rules III and this preliminary-end rule, the transition from the first to the second phase of the game occurs when the remaining number of neutral points is even. Therefore, in area rules III, if the first pass is made correctly, the opponent should also be able to pass, marking the preliminary end of the game. The important point is that if play is continued, the result will be the same whether the game is scored by the method of area rules III or by the territory-and-prisoners method.

Another point to note is that under the rule of two passes for the preliminary end, the first pass does not have to be the same as the first pass under area rules III.

The gist of this discussion is that if the preliminary-end rule is introduced into area rules III, together with a rule either adding points for the number of moves made after the preliminary end or requiring equal numbers of moves after the preliminary end, the score can be counted by prisoners and territory. Therefore, even though they differ in the method of transition from the first phase to the second phase of the game, territory rules I and area rules III are in complete agreement.

INDEX PROPOSED RULES OF GO
PREV NEXT

advertisements

index | rules of go

home > rules of go

Feedback: editor@gobase.org