[Welcome to Sensei's Library!]

StartingPoints
ReferenceSection
About


Referenced by
GettingSentePlays
MetaDiscussion
StableFollower
Priority
CommonMistakesInYose

Homepages
Icepick

 

Endgame Reckoner
    Keywords: EndGame

This is intended to be a quick reference to the sizes of various typical endgame plays. It was inspired by the Ready Reckoner page.

Assume all groups are alive.

Some of these positions I find are common in my games, but I'm not certain as to either the value of the play, or as to the best follow-up. Please comment and correct as needed.

See also: Common mistakes in Yose.

[Diagram]
4 points sente

4 points, double sente. W4 can be also played at a.

Bill: We cannot be sure that this is double sente without seeing the rest of the board. (See Double sente is relative.) In a real game this will typically arise after White has just played the marked stone, as part of a gote sequence for White.[1][2]

[Diagram]
6 points sente

6 points in double sente. I see this a lot.[3]



Two diagrams (W2 at W6) moved to Common mistakes in Yose.

[Diagram]
6 points sente

6 points, double sente. White has the one-point sente follow-up exchange, a for b.[4]

See How Big is the 6 point Double Sente

[Diagram]
9? points gote

The Monkey Jump 9 points in Gote. Can be sente depending if the marked stone is at a.



See Value of a Monkey Jump.

[Diagram]
2? points gote

Not certain of this one.

Charles In this position, six points.

mAsterdam Other remarks moved to Icepick's homepage.



[1]

Charles See example at double sente gain discussion. While I know what Bill is saying, I'm not sure that saying it here is compatible with a Reckoner. Such things are found in some of the Japanese endgame books, as lists of plays and values. All sorts of qualification and refinement have to go on, even when the values are given in a shaded way such as '3- points'.

In short, such a Reckoner cannot give all the information an expert would desire.

Bill: The point is, double sente is not a question of reckoning. Humungous is good enough. Already with Ogawa's book you see questions, because the value of a double sente should be a fraction with a denominator of 0! I note that, in the latest edition of the Nihon Kiin's Small Yose Dictionary, the reckoner does not include anything but gote. That avoids the problem of the size of double sente and the old problem of presenting 3-point sente and 3-point gote (deiri counting) side by side as 3-point plays. Despite the disclaimers, that led to confusion.

Charles I'm going to lose any argument I have with Bill on this area. But you do need to know the size of double sente, not just whether they'll be answered. For example some other sequence you play might lose you the double sente play, making it an adverse one-sided sente; and that's a trade-off you have to evaluate by factoring in the loss.

[2]

mAsterdam Would it be correct to state: when there is nothing bigger left on the board this is double sente? I (lowly DDK) am trying to grab this. After reading sente, double sente and double sente is relative this is how I understand (???) it. Apologies if this is the wrong place for asking. Maybe somebody who remembers being a beginner should edit those pages.

Charles You have to separate counting under certain assumptions, from judging whether those assumptions really hold. In practice certain plays are double sente: in theory there are always problems, concerned with the argument that with best play they might have been played earlier by one of the players.

Bill: It's double sente when, whoever makes the play now, the other player should reply in gote (perhaps after playing kikashi first). In general that means that the gote replies are bigger than anything else.

[3]

Bill: Ditto about double sente. In addition, this diagram leaves out too much about the surroundings. Why shouldn't Black cut at a, for instance? Either with B1 or after White's supposed sente sequence?

Charles Bill, I really think if we have to bring the lawyers in to draft the statements, we'll kill the usefulness by qualifying everything.

Bill: Well, Charles, I do not think that that diagram is useful. That's the point. It is not only so vague that we can't tell how large the plays are, it is so vague that we can't tell what correct play is.

[4]

Bill: Again, we cannot be sure that this is double sente. In fact, B1 is frequently ignored in pro games.

Charles Not something that is easily discussed; but a quick database search on a typical position suggests a play like B1 gets an immediate reply only 50% of the time. So Bill has a strong case here.

JF I wonder whether there's a useful distinction to be made. Of course it's a yose play (Japanese sense: sealing of boundaries), but there is a higher level in the hierarchy.

Further comments by JF moved to getting sente plays.



This is a copy of the living page "Endgame Reckoner" at Sensei's Library.
(OC) 2003 the Authors, published under the OpenContent License V1.0.