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Deiri
DeiriValue
Swing
SwingValue

Referenced by
Sente
Tenuki
MiaiCounting
SenteSente
DiscussionOfTheVa...
WhatWasTheHighest...
EquivalentGameToGo
GTLReview1558
GunSix
IntermediatePlays

 

Deiri Counting
    Keywords: EndGame

The value of a play indicates its urgency. Normally you should play the largest play, but there are exceptions. (See tedomari.)

The two main styles of evaluating plays are deiri (DEH-EAR'-EE) counting and miai (ME-EYE') counting. Miai values directly indicate the urgency of plays, while deiri values do so indirectly.

Let me start with a couple of examples.

[Diagram]
Diag.: Gote

If Black plays first she scores four points, represented as a positive integer, +4.

If White plays first she scores two points, represented as a negative integer, -2.

The deiri value is the difference between these two results (the swing), or 6 points.

We might call the deiri value of a play its swing value.


[Diagram]
Diag.: Sente.

After White 1 the score is -5.

After Black 1 White must play White 2 to live, and the net score is + 2.

The deiri value is the difference between these two results, or 7 points.

We may define deiri values as the difference between the count of the first stable position after Black plays first (called a Black follower) and that of the first stable White follower, assuming normally correct play.

A stable follower is one with a lower urgency than the original position. There is a potential circularity here, but a line of play eventually ends, as here, in a scorable position, or in a repetition, which is prohibited by the rules. (If it is not, the original position does not really have a value.)

--BillSpight



This is a copy of the living page "Deiri Counting" at Sensei's Library.
(C) the Authors, published under the OpenContent License V1.0.