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Up Topic Rybka Support & Discussion / Rybka Discussion / questions about the "contempt" and "outlook" settings
- - By jaeger1975 (**) Date 2007-06-22 20:06
hi friends

What are the main advantages of using this options? does it really influence in the style of play in Rybka? and does it influence in the choosing of the opening?

For example, I have a P4 3.2 Ghz HT and most of the users in playchess hav dual core machines and so on, Would you recommend me to use this options in order to improve the results in hte games?

thank ytou
Parent - - By lkaufman (*****) Date 2007-06-22 21:46
     Setting a small negative value for contempt, maybe 0.1 pawn or so, might make sense when you are playing substantially higher rated opponents as it should slightly increase the chances for a draw. Similarly a positive value is helpful to avoid draws against lower rated opponents. Outlook settings should only influence style, but are not believed to increase the chances of a favorable outcome.
Parent - - By Kapaun (****) Date 2007-06-22 21:50
You can only chose 1 or 2 or 3 etc. for contempt, not 0.1 or similar...
Parent - - By Fulcrum2000 (****) Date 2007-06-22 21:59
The input is in centipawns, so for 0.1 pawn you should enter 10
Parent - By Kapaun (****) Date 2007-06-22 22:05
Ah, okay... :)
Parent - - By Hetman (*****) Date 2007-06-23 12:49
Hi,

it is valuable information but how to know if i am palying against lower rated opponent ;-) ?

I understand that when i am playing for the win i shall make contempt positive when for the draw 0 or negative
but how it is playing with outlook ? Style has to be adjusted to the kind of the position.?!
Is the place where can i read about ? It would be nice to have sth with coments about how to adjust programm - Users Manual.

That what I have observed in the style of computer programms is that they are mostly going forward and they are not doing such a things like a holding the position. Could we influence that some-how ?

Regards
Hetman
Parent - - By lkaufman (*****) Date 2007-06-23 16:21
     I thought on all chess servers when you are challenged on make a challenge the opponent's rating is displayed, so this information is available. Anyway, if you are playing only other engines and you have inferior hardware, they will rarely be lower rated.
     Regarding outlook/style, I would suggest you just use the default. It's something to experiment with if you want to see the program play more like Tal or more like Petrosian, but she will probably do better if allowed to play like herself.
Parent - - By RFK (Gold) Date 2007-06-23 16:34 Edited 2007-06-23 16:36
Hi Larry,

But if knows he's playing with inferior hardware wouldn't he be better served with the Outlook at "very Pessimistic " or am I going backwards here? As is he's working with 32 bit single processor.
Parent - By lkaufman (*****) Date 2007-06-23 16:45
It is possible that this would increase the chances for a draw enough to offset the overall decline in playing strength, but I doubt it and we've never tested this theory so I wouldn't recommend doing so. It would take thousands of games to determine whether this strategy is sound. Also, if it is, it might only be valid if the rating difference is large.
Parent - - By Hetman (*****) Date 2007-06-23 18:54
thanks,
but what to do if i am lower ranked (have inferior hardware) but do have better position :-).
Shall i change to optimistic or stay with pessimistic outlook.
Regards
Hetman
Parent - - By lkaufman (*****) Date 2007-06-23 19:25
I would say it would depend on the type of advantage. As a human IM, if I have an extra pawn but an otherwise inferior position, I focus on my opponent's options (pessimistic outlook). If I have no long term advantages but better development or other temporary advantages, I focus on my own options (optimistic outlook). So if you are a strong enough player to make these judgements, you could try out my advice, but remember, this is my advice as an IM, not as a Rybka team-member. As a Rybka team member, I say it's safer to stick with the default.
Parent - - By Hetman (*****) Date 2007-06-24 07:32
Taking the point of human :-) I would like to know if there will be no conflict between contempt positive and pessimistic or opposite - contempt negative and outlook optimistic.
I understand that chess with computer are other chess but I would like to have some fun and have the impression that I am driving the car not the car is driving me ;-).

Regards
Hetman
Parent - - By lkaufman (*****) Date 2007-06-24 14:59
Contempt has only to do with your opinion of the opponent's level (compared to your own). Outlook can relate to the position. So I see no conflict between any possible settings of these options.
Parent - - By Hetman (*****) Date 2007-06-25 17:14
Thanks for the answer. It was not clear for me. With contempt positive the program tries not to repeat position and is playing for win. I thought that  it influences the algorithm. Outlook is influencing the way of searching i understand not the estimation function ?
Regards
Hetman
Parent - - By lkaufman (*****) Date 2007-06-25 21:19
That's right. Maybe future versions will have contempt influence the algorithm directly.
Parent - - By Hetman (*****) Date 2007-06-26 19:50
thanks.
My point is to know how to play against programs ;-).  Is it a meanigful difference when the programm estimates the move ... let's say 0.05
higher then other or it has no meaning ? 40 x 0.05 =  2. :-)
Regards
Hetman
Parent - - By lkaufman (*****) Date 2007-06-27 03:49
Certainly it has meaning. I would guess that if Rybka says one move is 0.05 better than another, the chances that it really is the better move are something like 70%. Probably Vas has a more accurate estimate of this. If Rybka always chose randomly between moves when the difference was .05 or less, she would be much weaker.
Parent - - By Hetman (*****) Date 2007-06-27 17:44
If I could ask next question. There are sometimes the moves with the same value but they are displayed in some order so they are sorted.
Does it have any meaning or it is the matter of the interface.
Regards
Hetman
Parent - - By lkaufman (*****) Date 2007-06-28 00:02
As far as I know, the first move listed (when they are tied in score) is the one that had the better score at a shallower depth.
Parent - - By Hetman (*****) Date 2007-06-29 20:26
Thanks.It is clear.
Going back to the pessimistic and optimistic outlook.
Playing on inferior hardware when I am on move and I am analysing my possibilities I am switching to pessimistic when I am analysing opponents move I am switching to optimistic. It is right solution ?
Regards
Hetman
Parent - - By lkaufman (*****) Date 2007-06-29 21:07
No, that doesn't make sense to me. Really, it is unlikely that anything you do will be as good as the default, but if you really want to vary the outlook settings, it only makes sense to me to do so based on the position. Logically, if you (meaning Rybka) are ahead in material, you should use pessimistic outlook, because you only need to be careful. If you are behind in material, you should use optimistic outlook, because with normal play you will probably lose, you need to look for something. With even material, use the default. If you are in the middle of a capture/recapture sequence, just use default until it is completed. This method simulated what strong human players do. Vas said his tests indicated this sort of thing didn't help, but I don't know if he did exactly this test.
Parent - - By Hetman (*****) Date 2007-06-30 20:51
Excuse me but for me there is the logic.
Where I am 'Rybka' and have pawn more I am using pessimistic when I am my opponet pawn down (analysing his possibilities) I am using optimistic. It is simulating the situation when I decided the move, done it  and I am analysing for my oponnent. Using your method it is the point to change outlook.

Regards
Hetman
Parent - - By lkaufman (*****) Date 2007-07-01 03:46
When you are playing a game, why would you have Rybka "analyse for my opponent" when it's not your turn? You should assume that he will play the move Rybka shows in the PV display, and have Rybka analyse what to play against that move. I think that is more useful than just having Rybka pretend to be the opponent. Of course, if you do use Rybka that way, then you are correct that Rybka would have to switch outlook based on switching from a pawn up to a pawn down.
Parent - By Hetman (*****) Date 2007-07-01 07:33
Thanks for the acnowledgement.
Why I am going move forward in analysis ? I think that:
1) The position has changed itself , i have met such the cause. The program has shown the evaluation for the move A 0.19 I made the move and
I have seen !  A1 0.07, A2 0.20, A3 0.21, A4 0.21. So in my opinion the estimation for A shall be 0.07 not 019 !
2) It is good to look on the position with the eyes of the opponent.

Regards
Hetman
Parent - By Vasik Rajlich (Silver) Date 2007-07-01 16:13
In these experiments, I used the root score from the last search to adjust the outlook.

Vas
Parent - By Vasik Rajlich (Silver) Date 2007-06-25 14:24
For what it's worth - quite some time ago, I tried having Rybka search more pessimistically (ie. looking harder for opponent's improvements on the PV) in better positions. It didn't seem to help.

Vas
Parent - - By Milton (***) Date 2007-06-25 21:29
Larry,

Does changing the contempt value to something other than 0 affect the numerical evaluations reported by Rybka?

Thanks,
Milton
Parent - - By lkaufman (*****) Date 2007-06-26 02:51
Usually no, but if the contempt value causes Rybka to reject a draw, then instead of a zero score it will report a score that is worse than zero. Contempt makes Rybka treat a draw as worse than zero, even though it would be reported as zero.
Parent - By Milton (***) Date 2007-06-26 12:23
Thanks for the reply.

Milton
Parent - - By MightyMouse (**) Date 2007-06-23 11:32
My experience with 2.3.2a suggests to keep the default engine settings. I believe the engine options such as Contempt and Outlook may be buggy and mess up the branching factor, etc.
Parent - By Cheer Date 2007-06-23 14:47
(Outlook = Neutral)   is the worst ?

1n6/1P2N1pP/2bq4/K6B/8/1r3N1k/p2R2p1/5Qr1 w - - 0 1


( What I found interesting about the first position is when I setup my machine and set it to play a game in 25 minutes 2.3.2a plays Bg4+ black replies Kg4 then 2.3.2a plays Nh2 with its settings at default but as soon as you choose any of the other outlooks it plays the correct Bg4+ and after Kg4 replies with Rd4+!! showing mate in 15 ....

Both 2.1o and 2.1d3 both instantly show Bg4+ and the correct Rd4+ at once at default ....)

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Up Topic Rybka Support & Discussion / Rybka Discussion / questions about the "contempt" and "outlook" settings

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