How powerful is the Queen compared to 2 Rooks ?

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lkaufman
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Re: How powerful is the Queen compared to 2 Rooks ?

Post by lkaufman » Wed Feb 06, 2019 6:00 pm

hgm wrote:
Wed Feb 06, 2019 9:31 am

For one, there is nothing wrong with a score of +1.53 and failing to win: the draw margin in Chess is about 1.5 Pawn, and +1.53 thus means the position offers about a 50-50 chance on win / draw.

I was very surprised to read this sentence. All of my tests in past years put the 50/50 win/draw line at about 3/4 of a pawn, not 1.5 pawns. Of course it depends a bit on which engine you are talking about and time limits, etc., but for Komodo (and Houdini too I think) 3/4 pawn is about right. A "clean" pawn up is evaluated as somewhat less than 1.0 by Komodo in the opening and somewhat more in the endgame, but on average 1.00 should be pretty close to accurate. The recent SF versions have very inflated scores (to say nothing of Lc0) which report a neutral pawn plus as more than 1.0, so if yu are basing this on recent SF that could be part of the problem, but even with SF I don't think the 50/50 line would be much over 1.0. So I'm asking what your source for the 1.5 pawn claim was; perhaps it was based on some very weak engine, or one that reports unrealistic scores for a pawn plus?
Komodo rules!

Chessqueen
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Re: How powerful is the Queen compared to 2 Rooks ?

Post by Chessqueen » Wed Feb 06, 2019 6:39 pm

lkaufman wrote:
Wed Feb 06, 2019 6:00 pm
hgm wrote:
Wed Feb 06, 2019 9:31 am

For one, there is nothing wrong with a score of +1.53 and failing to win: the draw margin in Chess is about 1.5 Pawn, and +1.53 thus means the position offers about a 50-50 chance on win / draw.

I was very surprised to read this sentence. All of my tests in past years put the 50/50 win/draw line at about 3/4 of a pawn, not 1.5 pawns. Of course it depends a bit on which engine you are talking about and time limits, etc., but for Komodo (and Houdini too I think) 3/4 pawn is about right. A "clean" pawn up is evaluated as somewhat less than 1.0 by Komodo in the opening and somewhat more in the endgame, but on average 1.00 should be pretty close to accurate. The recent SF versions have very inflated scores (to say nothing of Lc0) which report a neutral pawn plus as more than 1.0, so if yu are basing this on recent SF that could be part of the problem, but even with SF I don't think the 50/50 line would be much over 1.0. So I'm asking what your source for the 1.5 pawn claim was; perhaps it was based on some very weak engine, or one that reports unrealistic scores for a pawn plus?
Thanks for clarifying that, I was also ready to say that if Komodo using EGT give a score of 0.00 and HG still insist that the white position is winning why doesn't he show us which program can win with white against Komodo, then to clarify that when a program give an evaluation either if it search it or use EGT as 0.00 it is still an evaluation which reflect the final search of an engine or after it has search the position in its EGT as drawish in either case a 0.00 evaluation is a 0.00 evaluation. I also believe that a much stronger engine can be develop by using a combination of Neural Networks combined with either Alpha-beta Search or Pruning.

This is the position where Komodo evaluate the position as dead even 0.00
[D]8/8/6BB/2n5/3bp3/1kp2PP1/4K2P/8 b - - 0 1

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hgm
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Re: How powerful is the Queen compared to 2 Rooks ?

Post by hgm » Wed Feb 06, 2019 6:51 pm

lkaufman wrote:
Wed Feb 06, 2019 6:00 pm
hgm wrote:
Wed Feb 06, 2019 9:31 am

For one, there is nothing wrong with a score of +1.53 and failing to win: the draw margin in Chess is about 1.5 Pawn, and +1.53 thus means the position offers about a 50-50 chance on win / draw.
I was very surprised to read this sentence. All of my tests in past years put the 50/50 win/draw line at about 3/4 of a pawn, not 1.5 pawns. Of course it depends a bit on which engine you are talking about and time limits, etc., but for Komodo (and Houdini too I think) 3/4 pawn is about right. A "clean" pawn up is evaluated as somewhat less than 1.0 by Komodo in the opening and somewhat more in the endgame, but on average 1.00 should be pretty close to accurate. The recent SF versions have very inflated scores (to say nothing of Lc0) which report a neutral pawn plus as more than 1.0, so if yu are basing this on recent SF that could be part of the problem, but even with SF I don't think the 50/50 line would be much over 1.0. So I'm asking what your source for the 1.5 pawn claim was; perhaps it was based on some very weak engine, or one that reports unrealistic scores for a pawn plus?
It was just a rule of thumb I used when I was still playing chess myself: being a clean Pawn ahead is usually not enough to win the game. (Of course I was just a patzer compared to you!) Most KRPKR are draw, with minors instead of Rooks it is even a dead draw. And in these cases the Pawn even is a passer, which should put it on the high end of the Pawn-value spectrum. Even KPK is often a draw, although without pieces advatages count much heavier.

My experience with weak engines (Fairy-Max ~2000 Elo) is that classical Pawn odds results in a 68% score (color-averaged). This doesn't seem to depend much on the level of play (as changed by varying the TC). I once saw a posting on the Rybka forum where someone had measured this with Rybka to be 70-72% (but I was not sure whether this was color averaged). Note that a 50-50 win:draw would be a 75% score, so a draw margin > 1 Pawn seems even to hold in the opening.

I don't know anythinhg about Komodo's evaluation scale; I don't have Komodo. More importantly, the 1.53 score was ascribed to LC0, so it really depends on how LC0 translates winning prospects into centi-Pawn. Which is just a matter of presentation, and has nothing to do with the quality of play: any monotonous transformation of the score would lead to exactly the same play.

Evaluating the given position as 0.00 seems a mistake: it means the engine will give up trying, even against a much weaker opponent. No matter how large a contempt you set. The contempt would only help to avoid immediate draws, but it would not help to distinguish between lines that keep the opponent under pressure, and those that blunder away one or two Pawns.

What would be Komodo's static evaluation of that position, btw?

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Nordlandia
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Re: How powerful is the Queen compared to 2 Rooks ?

Post by Nordlandia » Fri Feb 08, 2019 5:54 pm

Have you tried fairy max with a2-pawn odds. a2 odds is considered the lowest valuable pawn.

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hgm
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Re: How powerful is the Queen compared to 2 Rooks ?

Post by hgm » Fri Feb 08, 2019 6:25 pm

No, I have not tried that. Usually I shuffle the back-rank pieces in the starting position to drive up game diversity, and which Pawn is most valuable is no doubt dependent on what exactly is behind it. And by far the most data I collected even had some fairy pieces behind it. The result appears always to be the same: the score drops ~18% (if it was and stays between 30% and 70%) when you delete the Pawn.

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Re: How powerful is the Queen compared to 2 Rooks ?

Post by Chessqueen » Fri Feb 08, 2019 8:43 pm

Nordlandia wrote:
Fri Feb 08, 2019 5:54 pm
Have you tried fairy max with a2-pawn odds. a2 odds is considered the lowest valuable pawn.

Look at this game, it is ridiculous, SF with 7Men TB playing versus Leela without a EGT. I believe that SF and Komodo should also play without EGT. :mrgreen:
https://tcec.chessdom.com/

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Re: How powerful is the Queen compared to 2 Rooks ?

Post by Chessqueen » Sat Feb 09, 2019 6:25 am

Chessqueen wrote:
Fri Feb 08, 2019 8:43 pm
Nordlandia wrote:
Fri Feb 08, 2019 5:54 pm
Have you tried fairy max with a2-pawn odds. a2 odds is considered the lowest valuable pawn.

Look at this game, it is ridiculous, SF with 7Men TB playing versus Leela without a EGT. I believe that SF and Komodo should also play without EGT. :mrgreen:
https://tcec.chessdom.com/
I just wonder what the score would be if Stockfish was not using 7Men TB and if in reality it makes much of a difference? Any predictions or comments. I would say the score would be almost the same, so far the EGT of Stockfish has not made much difference as far as winning any endgame. I still believe that stockfish can find the best move based on search alone under this time long control unless it was blitz. Amoyhert observation is what kind of opening is Leela creating? is is out of this World! Is Leela creating new kind of opening on its own? What would you call this latest opening of Leela?

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Guenther
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Re: How powerful is the Queen compared to 2 Rooks ?

Post by Guenther » Sat Feb 09, 2019 7:38 am

Chessqueen wrote:
Fri Feb 08, 2019 8:43 pm
Nordlandia wrote:
Fri Feb 08, 2019 5:54 pm
Have you tried fairy max with a2-pawn odds. a2 odds is considered the lowest valuable pawn.

Look at this game, it is ridiculous, SF with 7Men TB playing versus Leela without a EGT. I believe that SF and Komodo should also play without EGT. :mrgreen:
https://tcec.chessdom.com/
Not informed and wrong blabber as usual. This thread is more like a barbers' chat than talkchess.
Of course LC0 plays with EGT too (6men in this case, they did not yet care for 7men implementation, there are other priorities).

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Re: How powerful is the Queen compared to 2 Rooks ?

Post by Chessqueen » Sat Feb 09, 2019 10:34 am

Guenther wrote:
Sat Feb 09, 2019 7:38 am
Chessqueen wrote:
Fri Feb 08, 2019 8:43 pm
Nordlandia wrote:
Fri Feb 08, 2019 5:54 pm
Have you tried fairy max with a2-pawn odds. a2 odds is considered the lowest valuable pawn.

Look at this game, it is ridiculous, SF with 7Men TB playing versus Leela without a EGT. I believe that SF and Komodo should also play without EGT. :mrgreen:
https://tcec.chessdom.com/
Not informed and wrong blabber as usual. This thread is more like a barbers' chat than talkchess.
Of course LC0 plays with EGT too (6men in this case, they did not yet care for 7men implementation, there are other priorities).
Okay, if you want it that way and start calling me name a blabber is someone who talks about somebody else. therefore, I can only imagine you looking like the first one on the upper left of these photos, since I can NOT think of nothing good about you a a decent person ==>
https://www.google.com/search?rlz=1C1EK ... 20&bih=969

Chessqueen
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Re: How powerful is the Queen compared to 2 Rooks ?

Post by Chessqueen » Sat Feb 09, 2019 11:12 am

Chessqueen wrote:
Sat Feb 09, 2019 10:34 am
Guenther wrote:
Sat Feb 09, 2019 7:38 am
Chessqueen wrote:
Fri Feb 08, 2019 8:43 pm
Nordlandia wrote:
Fri Feb 08, 2019 5:54 pm
Have you tried fairy max with a2-pawn odds. a2 odds is considered the lowest valuable pawn.

Look at this game, it is ridiculous, SF with 7Men TB playing versus Leela without a EGT. I believe that SF and Komodo should also play without EGT. :mrgreen:
https://tcec.chessdom.com/
Not informed and wrong blabber as usual. This thread is more like a barbers' chat than talkchess.
Of course LC0 plays with EGT too (6men in this case, they did not yet care for 7men implementation, there are other priorities).
Okay, if you want it that way and start calling me name a blabber is someone who talks about somebody else. therefore, I can only imagine you looking like the first one on the upper left of these photos, since I can NOT think of nothing good about you a a decent person ==>
https://www.google.com/search?rlz=1C1EK ... 20&bih=969
I apologize, I did NOT meant to compare you with the uglier Fish that looks like an ugly person face. The only reason why I said that LCZero was not using EGT, is because I did not see it on this website. But you probably read it someplace, therefore you were better informed than I am. What I really meant to say is that both programs should use the same EGT without disadvantage to LCZero. Now I see TB Hits for both programs. :oops: The match is getting closer as it progresses 14 to 13 in favor of Stockfish so far.

https://tcec.chessdom.com/

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