Not logged inRybka Chess Community Forum
Up Topic Rybka Support & Discussion / Aquarium / move repetition detection: red 'R' ?
- - By Boombaard (**) [nl] Date 2017-04-03 12:11
I have a CC game running in IDEA 2016.

In general Aquarium detects move (position) repetition by giving a red 'R' signal. However, it sometimes also gives a red 'R' while the position is NOT a repetition. The 'R' should be gray, not red, because a pawn was moved, so a repetition is impossible. Is this a known bug?
This is important for me, because the IDEA tree gives an ocean off shuffling moves, some of them leading to a repetition a lot of moves further in the game. Then I dont know if a move really leads tot repetition or not. The evaluation of the position is about + 0,30, so still no draw in sight.

Does someone know how I get the red 'R' properly functioning? Thanks in advance!
Parent - - By pawnslinger (***) [us] Date 2017-04-03 15:28
The position is not necessarily a repetition... it could just be a transposition.  I think that Aquarium has difficulty distinguishing between these two situations.  Even some engines have trouble with this problem.  The only way I have found to resolve the situation is thru the IA type analysis functions and back-sliding thru the variations, to help the engine/Aquarium get over their horizon, so they can "see" the better way forward.  As otherwise, both engines and Aquarium tend to spend a lot of time, ruling out dead-end variations.

This definitely is where the interactive part comes into play, and where superior human help/intuition comes into play.
Parent - - By Boombaard (**) [nl] Date 2017-04-03 18:58
Transpositions, yeah, probably. But I don't care when analysing a specific postion. All I want is avoiding a draw by position repetition. An ambiques meaning of the red 'R' is confusing: transpostion is different to position repetition.

Manually adding moves to get over the horizon: I tried for hours and hours, but there are too many transpostions (!) to remember if a postion occured before. Even worse, because of those transpositions every move you go further through the tree there are about 5 equal options (same evals). They are not sorted by means of shortest way to the horizon. I go throug and through them, often realizing after many moves I have the same postion as  e.g. 12 moves before. So I even dont manage to reach the horizon!
And all the time a red 'R' is shown. Very confusing and frustrating.

Now, I moved to the old fashioned way: running a game from this position. Surely now Aquarium wont allow a postion repetition the first 30 moves or so. But I dont build a tree like IDEA.

But, thank you for your answer anyway!
Parent - By pawnslinger (***) [us] Date 2017-04-04 05:22
Actually, a repeat position is technically a transposition -- i.e. the same position arrived at by a different set of moves.  It is difficult for most computer programs to tell the difference.  And positions that give rise to many transpositions are desirable... there are more ways for your opponent to go wrong.  But yes, these positions are often most difficult to evaluate correctly for you also.  In a clear cut position with few transpositions, it is hard for any decent player to go wrong.  Especially if he has a decent engine to evaluate the position.

That is the beauty of Aquarium, you can extend the evaluation for many days, suspending sometimes to run other evaluations... assuming you have time left in your side of the game.  For example, I am working on such a position right now, I have run Aquarium IDeA against it for the last 2 days, with more than 12,000 evals on this position alone, and I am still not happy with the result.  I have 17 more days until double time kicks in, and I have more than 100 days on my clock left.  I plan to use a lot of that time.  Aquarium makes it possible.  And while doing that I continue to analyze other games that are less difficult.
Up Topic Rybka Support & Discussion / Aquarium / move repetition detection: red 'R' ?

Powered by mwForum 2.27.4 © 1999-2012 Markus Wichitill