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Up Topic Rybka Support & Discussion / Rybka Support / Rybka takes 10 seconds to play a mate in 1!
- - By dragon49 (****) [us] Date 2010-06-01 23:06
As I watch Deep Rybka 4 SSE42 x64 play, I notice some odd behavior not seen with Rybka 3:  At the end of a game, when she starts announcing mate, she takes far too long to make moves.  In the attached game, she took 10 seconds to play the mate in 1, all the time, showing the mate in 1 in the analysis window!!  Also, look at the length of times that she took to move, before the mate.

I am using the complete 5 man tablebase set and running rybka with all default settings.

Could somebody explain this behavior to me. Why does she do this? In this game, why did she take 10 seconds to play a mate in one, that she saw???  Also, Vas, please fix this.  In addition to the silliness, this wastes a lot of time, when playing a long number of games in a match or tournament.
Attachment: 1.pgn (5k)
Parent - By Banned for Life (Gold) Date 2010-06-01 23:37
She is probably savoring the win! :-D
Parent - - By Albert Silver (***) [br] Date 2010-06-01 23:47
So she took 10 seconds to play the move, not find it.
Parent - By dragon49 (****) [us] Date 2010-06-01 23:49
Correct - I edited my title.  The correction does not reduce the absurdity of the situation.
Parent - - By Vempele (Silver) [fi] Date 2010-06-01 23:54
She's just looking for a shorter mate. The same thing was complained about during beta testing (it wasn't a mate in 1, though).
Parent - By dragon49 (****) [us] Date 2010-06-02 00:05
I think I see what's going on:  I seem to remember Rybka 3 discussions where users complained that Rybka would find a mate, then play it out instantly, and not look for a shorter mate.  Vas decided to accommodate the posters, but left in some funny bugs, like looking for a mate that is shorter than 1?!
Parent - By Banned for Life (Gold) Date 2010-06-02 00:09
She might be looking for a good ponder move! :-D
Parent - - By Leto (***) [us] Date 2010-06-02 01:58
In this case it appears to be an annoying bug.  Hard to find a shorter mate than a mate in 1!
Parent - - By Cubeman (**) [nz] Date 2010-06-02 03:55
Sam Lloyd composed a mate in 0.The story goes that some guy found his problems too hard and said to him can you make something easier.So Sam constructed a position with 9 pawns on board of 1 colour.And when any of pawns were removed from the board then the opponent was checkmated.
Parent - By sarciness (***) [cn] Date 2010-06-02 05:07
I've heard of a mate in 1/2. Finishing castling!
Parent - By Lukas Cimiotti (Bronze) [de] Date 2010-06-02 07:02
Rybka 3 could indicate a mate in 0 :lol:
Parent - By Felix Kling (Gold) [de] Date 2010-06-02 05:44
well, she plays it but enjoys every second before playing it :)
Parent - - By Hurnavich (Bronze) Date 2010-06-02 06:17
Hi,i have had the same problem,i7 950 cpu

Hurnavich
Parent - - By Lukas Cimiotti (Bronze) [de] Date 2010-06-02 07:11
It's not really a problem, but a known behavior. It costs time in situations when the path to mate is clear, but it also has quite positive aspects. Using Rybka 3 with lots of tablebases you will see games in which Rybka sacs a queen or a rook to get into a winning tablebases position. In many of these cases a bit of thinking avoids these unnatural sacrifices and leads to a shorter mate. Of course there are situations in which this doesn't make any sense - like if there is a mate in 1.
Parent - - By dragon49 (****) [us] Date 2010-06-02 12:44
Lucas,

I get your points.  My question is, how hard would it have been for Vas to put in a condition causing Rybka to stop thinking, if she has found a mate in 1?  From a pure mathematical/programming standpoint, is it possible to not classify this as a bug?  Is somebody going to come out with an argument that fixing this will subtract a few ELO points from Rybka.
Parent - By Lukas Cimiotti (Bronze) [de] Date 2010-06-02 12:47
My name is Lukas.
I's no problem to change that behavior - and it won't cost any Elo points. I guess Vas will do that in Rybka 5.
Parent - By Vasik Rajlich (Silver) [pl] Date 2010-06-04 14:41
It's a known issue - Rybka doesn't know that you can't do better than mate-in-1. :)

If you want to save CPU time, you can play with resign enabled in the GUI.

Vas
Up Topic Rybka Support & Discussion / Rybka Support / Rybka takes 10 seconds to play a mate in 1!

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