Houdini Engine behaviour

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Matioupi
Posts: 28
Joined: Mon Aug 09, 2010 8:30 am
Real Name: MP

Houdini Engine behaviour

Post by Matioupi » Fri Dec 24, 2010 6:35 pm

Hello,

i'm quite a newbie to chess and computer chess, but i noticed a strange behaviour (at least strange to my mind) with Houdini 1.5 engine.

I'm working with the Fritz12 GUI.
I've been analysing some lost position in analysis mode for a long time with 3 main lines displayed.
After a while, the computer starts showing the # (mate symbol) followed by the number of moves (something from 20 to 60) for all 3 lines.

The strange thing is that the number of moves for the mate should (i think) decrease with time (if computer find a better move for the attacking camp) but it's actually raising sometimes which i find a bit dubious. If the # (mate) symbol is displayed, how could the defender camp find a move that let him alive for a longuer sequence ?

I hope I made myself clear enought...

This test was run with a 1Gb hash on a Core2 duo comuter under Vista

Regards,

Mathieu

Kurt
Posts: 20
Joined: Sun Dec 12, 2010 7:11 pm

Re: Houdini Engine behaviour

Post by Kurt » Sat Dec 25, 2010 3:20 pm

Maybe the move order was not the best in the mate line and
the engine had noticed this sometime later.
Kurt

Matioupi
Posts: 28
Joined: Mon Aug 09, 2010 8:30 am
Real Name: MP

Re: Houdini Engine behaviour

Post by Matioupi » Mon Dec 27, 2010 6:51 am

Hello,

I'm not sure i'm understanding well but if the engine annonce a mate in N move line, then it hase be sure to mate in "at most" N moves, isn't it ?

Then the only way the N number should change is by lowering, if the engine finds a better "attacking" move (there should be no better defending move) but i don't see a good reason why this number should increase as i observed...

Any clue ?

Regards,

Mathieu

Matioupi
Posts: 28
Joined: Mon Aug 09, 2010 8:30 am
Real Name: MP

Re: Houdini Engine behaviour

Post by Matioupi » Mon Dec 27, 2010 7:25 pm

Q7/2k5/1p1q3p/2bB4/6R1/P4P1P/KPP3P1/4r3 b - - 0 47

The following position gives the described behaviour :

i'm displaying the engine output for the 2 first lines which are :
1 : 47..Re8
2 : 47 : Rd1

After some time, line 2 shows mate in 29 and later on, it shows mate in 32 (about 18 minutes on my machine)

Regards,

Mathieu

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