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 Post subject: Re: What is the smallest miai value you can build ? #21 Posted: Thu Mar 02, 2023 6:52 am
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RobertJasiek wrote:
@Gerard: Yes, it is rare is that the koloser has no compensation at all for losing the ko. However, why do you have a problem with this and, e.g., komaster evaluation? Such a model does consider compensation as gains T of each play elsewhere. Only komonster evaluation allows T to drop to 0 for no compensation.

@NordicGoDojo: Another remark on possibly unifying endgame evaluation theories and consideration of the last move: If we could already unify all endgame evaluation theories and solve the game, very likely it would be impractical to apply such a unified theory during a game. Combinatorial game theory started with exactness also considering the last move of a game. Bill Spight's endgame theory and my endgame theory involving move values, or the combinatorial game theory's orthodoxy and thermography are endgame evaluation theories that, in the general case, are approximations and ignore, in particular, consideration of the last move. Unless very late during the endgame, it is an advantage and great simplification to ignore, in the general case, the fight of getting the last move.

`[go]\$\$B Black to play\$\$----------------------\$\$ . . . . . O X . . . |\$\$ . . . . . O X X X . |\$\$ . . . . . O O O X X |\$\$ . . . . . . . O O O |\$\$ . . . . . . . . . . |\$\$ . . . . . . . . . . |[/go]`

Without taking into account ko threats in the environment the common analyse of this position is quite easy.
The resulting count when black plays first is 3 points
The resulting count when white plays first is -14 points
=> according to the theoritical theory the move value here is m = (14 + 3) / 3 = 5 2/3.

Assume now black is komaster. Can you explain how do you analyse now the position taking into account a possible compensation T for white?
How do you choose the T value?
At what temperature will black play locally to avoid the ko?
At what temperature will white play locally in order to force black to use her ko threat?
If it not easy to answer these questions then surely I will conclude (as you did with the problem of playing the last move) it is an advantage and great simplification to ignore ko threats in the environment.

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 Post subject: Re: What is the smallest miai value you can build ? #22 Posted: Thu Mar 02, 2023 7:43 am
 Judan

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"the theoretical theory" - What theory? (I guess you might mean vanilla modern endgame theory modified by some uncommented shortcuts for negative numbers.)

Komaster can be used as its definition but still the definition is specialised. Ok, maybe you want to (ab)use this word in an informal sense.

The is placid, right? Therefore, we do not need generalised komaster thermography with all values of T.

It should be sufficient to calculate your vanilla move value and know the temperature T of the environment of the actual position. This T is not chosen but determined as the value of a largest (simple) gote. (If there is a hot ensemble, first play it out, then we have T of the whole board follower.

Suppose we cannot read out ko fights etc. but need to rely on values. Either player wants to play locally at the same temperature T when T = M, ok more likely when T ~= M.

Easy enough to answer if the ko threat playout is too difficult:) If the ko threat playout can be read, then to hell with values but use the method of reading and counting, possibly adjusting T/2 afterwards for the value of starting in the environment after an unequal number of played moves.

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 Post subject: Re: What is the smallest miai value you can build ? #23 Posted: Thu Mar 02, 2023 9:14 am
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RobertJasiek wrote:
"the theoretical theory" - What theory? (I guess you might mean vanilla modern endgame theory modified by some uncommented shortcuts for negative numbers.)

Komaster can be used as its definition but still the definition is specialised. Ok, maybe you want to (ab)use this word in an informal sense.

The is placid, right? Therefore, we do not need generalised komaster thermography with all values of T.

It should be sufficient to calculate your vanilla move value and know the temperature T of the environment of the actual position. This T is not chosen but determined as the value of a largest (simple) gote. (If there is a hot ensemble, first play it out, then we have T of the whole board follower.

Suppose we cannot read out ko fights etc. but need to rely on values. Either player wants to play locally at the same temperature T when T = M, ok more likely when T ~= M.

Easy enough to answer if the ko threat playout is too difficult:) If the ko threat playout can be read, then to hell with values but use the method of reading and counting, possibly adjusting T/2 afterwards for the value of starting in the environment after an unequal number of played moves.
Well, if I understand correctly komaster has nothing to do with placid ko.
So let'take NordicGoDojo example, assuming black is komaster

`[go]\$\$\$\$---------------------------------------\$\$ | . X . . . . . . .\$\$ | X X . . X . X O O\$\$ | . X . . . X O . .\$\$ | X X X X X O O O O[/go]`

How do you choose the T value?
At what temperature will black play locally to avoid the ko?
At what temperature will white play locally in order to force black to use her ko threat?

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 Post subject: Re: What is the smallest miai value you can build ? #24 Posted: Thu Mar 02, 2023 9:30 am
 Judan

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This ko is hyperactive so generalised komaster thermography or study of ko threats can reveal more information and we should not expect a single T to answer all questions.

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 Post subject: Re: What is the smallest miai value you can build ? #25 Posted: Thu Mar 02, 2023 11:34 am
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RobertJasiek wrote:
This ko is hyperactive so generalised komaster thermography or study of ko threats can reveal more information and we should not expect a single T to answer all questions.

Let's complete the position to be clearer
`[go]\$\$\$\$---------------------------------------\$\$ | . X . . . . . . . . . O . .\$\$ | X X . . X . X O O O O O . . \$\$ | . X . . . X O . . . . . . .\$\$ | X X X X X O O O O . . . . .\$\$ | . . . . . . . . . . . . . .[/go]`

Unless very late during the endgame (I mean t ~= 1), I do not understand why this situation is really hyperactive.

My analyse is the following :
Black to play:
`[go]\$\$B\$\$---------------------------------------\$\$ | . X . . . . 3 1 2 . . O . .\$\$ | X X . . X . X O O O O O . . \$\$ | . X . . . X O . . . . . . .\$\$ | X X X X X O O O O . . . . .\$\$ | . . . . . . . . . . . . . .[/go]`

White to play, I assume
`[go]\$\$W\$\$-------------------------------\$\$ | . X . . . . 1 . . . . O . .\$\$ | X X . . X 2 X O O O O O . . \$\$ | . X . . . X O . . . . . . .\$\$ | X X X X X O O O O . . . . .\$\$ | . . . . . . . . . . . . . .[/go]`

followed later by
`[go]\$\$B\$\$-------------------------------\$\$ | . X . . . 1 O 2 . . . O . .\$\$ | X X . . X X X O O O O O . . \$\$ | . X . . . X O . . . . . . .\$\$ | X X X X X O O O O . . . . .\$\$ | . . . . . . . . . . . . . .[/go]`

Comparing these diagramm I consider the initial position is sente for white (3 points in reverse sente for black).
IOW white to move will be able to play hane when temperature is still greater than t = 3.

In this hypothesis
`[go]\$\$W\$\$-------------------------------\$\$ | . X . . . b O . . . . O . .\$\$ | X X . . X a X O O O O O . . \$\$ | . X . . . X O . . . . . . .\$\$ | X X X X X O O O O . . . . .\$\$ | . . . . . . . . . . . . . .[/go]`

and assuming an ideal or rich environment then a black move at "a" seems better than a black move at "b" because in such environment black will be able later to play at "b" in sente.

My conclusion : unless very late during the endgame the position is for me not hyperactive.

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 Post subject: Re: What is the smallest miai value you can build ? #26 Posted: Thu Mar 02, 2023 12:34 pm
 Judan

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Gérard TAILLE wrote:
Unless very late during the endgame (I mean t ~= 1), [...] not [...] really hyperactive.

Of course.

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 Post subject: Re: What is the smallest miai value you can build ? #27 Posted: Thu Mar 02, 2023 2:36 pm
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RobertJasiek wrote:
Gérard TAILLE wrote:
Unless very late during the endgame (I mean t ~= 1), [...] not [...] really hyperactive.

Of course.

OK let's now assume t = 1 (which is quite already irrealistic because in practice, if white is able to play hane, then the temperature of the environment has quite no chance to have already dropped to t = 1).
Anyway we are handling infinitesimals aren't we?

`[go]\$\$W\$\$-------------------------------\$\$ | . X . . . b O . . . . O . .\$\$ | X X . . X a X O O O O O . .\$\$ | . X . . . X O . . . . . . .\$\$ | X X X X X O O O O . . . . .\$\$ | . . . . . . . . . . . . . .[/go]`

Assume black has got a ko threat available
Black plays "a":
`[go]\$\$B\$\$-------------------------------\$\$ | . X . . 3 2 O 4 . . . O . .\$\$ | X X . . X 1 X O O O O O . .\$\$ | . X . . . X O . . . . . . .\$\$ | X X X X X O O O O . . . . .\$\$ | . . . . . . . . . . . . . .[/go]`

Black plays "b":
`[go]\$\$B\$\$-------------------------------\$\$ | . X . . . 1 O . . . . O . .\$\$ | X X . . X 2 X O O O O O . .\$\$ | . X . . . X O . . . . . . .\$\$ | X X X X X O O O O . . . . .\$\$ | . . . . . . . . . . . . . .[/go]`

ko threat, answer to ko threat
`[go]\$\$B\$\$-------------------------------\$\$ | . X . . . X O 6 . . . O . .\$\$ | X X . . X 7 5 O O O O O . .\$\$ | . X . . . X O . . . . . . .\$\$ | X X X X X O O O O . . . . .\$\$ | . . . . . . . . . . . . . .[/go]`

When comparing the two diagramms black at "b" gains 1 point but is gote. Assuming an ideal or rich environment at temperature t = 1 then "a" and "b" gives the same result. Because black "b" loses one ko threat that means that black "a" is still better that black "b".

Technically black "b" might be better if if allows black to take the last infinitesimal, ... but I understood you do not wish to take the last move into consideration.

Conclusion : providing you do not want to take into account the last move issue then the black move at "b" can (should) be played only after all infinitesimals => we are in the very very late endgame and this situation is more and more irrealistic in practice.

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