Trying to find a weird mate in 1...
Posted: Mon Jul 22, 2019 3:24 pm
Well hello again everybody. Martin Bryant here... author of the White Knight and Colossus programs back in the infancy days of micro computer chess. The last version of my UCI engine was 2008b! Where did the last 11 years go?! Anyway... as I'm now approaching retirement I've been giving some thought as to how to fill my time and inevitably dusting of the Colossus code was an option. I have been working on it for about a month now and 'engine fever' has certainly taken hold again! With 64-bit processors being ubiquitous these days the first thing I have done is to recode Colossus to use bitboards. Aren't they elegant?! The new version is now producing correct Perft counts and playing whole games without error. It's much simplified compared to 2008b as I stripped out a mountain of extensions/reductions/EGTB/immediate-mates/etc code just so that I could see the wood for the trees during the bitboard reconstruction. It's playing at a level marginally below 2008b at the moment but hopeful that when I start putting stuff back in it will eventually be an improvement. Fingers crossed!
Anyway... to the subject of the post... I recall seeing years ago a contrived mate-in-1 which gave some engines trouble as it blew up the quiescence search. It's not that important but I just wanted to find it again to see how Colossus fared, but sadly I can't find it anywhere
From what I can remember it had 3 (or maybe 4?) rows of pieces (lots of promoted queens) across the middle of the board with the victim King on h3 I think and an attacking queen (probably on a1?) waiting to deliver Qh1 mate.
Does anyone else remember this position (or one similar) and could provide a link to an earlier post or the FEN? Hope I've given enough info... sorry I can't remember anything more specific.
Many thanks!
Anyway... to the subject of the post... I recall seeing years ago a contrived mate-in-1 which gave some engines trouble as it blew up the quiescence search. It's not that important but I just wanted to find it again to see how Colossus fared, but sadly I can't find it anywhere
From what I can remember it had 3 (or maybe 4?) rows of pieces (lots of promoted queens) across the middle of the board with the victim King on h3 I think and an attacking queen (probably on a1?) waiting to deliver Qh1 mate.
Does anyone else remember this position (or one similar) and could provide a link to an earlier post or the FEN? Hope I've given enough info... sorry I can't remember anything more specific.
Many thanks!