Author: Stuart Cracraft
Date: 16:09:45 09/02/04
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On September 02, 2004 at 19:06:06, GeoffW wrote: >>Hi Geoff, >> >>I think one possibility is this... >> >>I don't increment 'ply' when null-moving... (i decrement remaining depth, of >>course) >> >>That may explain why Crafty works with +1 and TRACE works with +2. >> >>In fact, that may point out a capital search bug in TRACE. My nullmoves >>'corrupt' the true value of ply. Not good. And it explains some odd search >>behaviours. Also, I cannot test if (ply & 1) to see if the side to move is a >>particular colour. I will fix this in the next week or so and see if it helps. >>Oooooohhh.... I have a good feeling about this... >> >>Ross > >Hi Ross > >Yes, that does look like the explanation as to why there is a difference of +1 > >I was interested to see what effect the correction would have so I quickly put a >ply++ and ply-- around the null move search call. >Not sure what your code will do but mine went Splat !! >Thats going to be a fun one to debug, no idea what is causing it at the moment, >hope your works better than mine. I will be interested to know how it worked for >you ? > > Regards Geoff I was doing a ply+1 to the null move search with a mate threat of -MATE+ply+2. When I removed the ply+1 and just had ply (no increment), and kept -MATE+ply+2, my solutions with MATETHREAT enabled went up to the same level as I get without MATETHREAT on. Formerly, having MATETHREAT enabled cost me 4 or 5 positions (out of 300). I had hoped for beating my no-MATETHREAT setting with my MATETHREAT but apparently no luck. At least it doesn't hurt, is parity, and theoretically better. I don't think there is a bug. The code is rather simple. Stuart
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