World Draughts Forum

How does one (typically) implement left/right imbalance ? What first comes to my mind is simply counting the pieces on the left and right side of the board but that seems to be a little too "unprecise". edit: I tried to give a simple explanation, but I got it wrong. For the white men on the left si...

I routinely get 38M n/s right out of the opening book on my Xeon @3.6 Ghz Maybe it's time for me to get a new PC?! I was recalling the speed from memory. I've been working on the 8x8 version of kingsrow lately, which is a little slower. I just tested the 10x10 version, and it's about 10M n/s, so ab...

Many thanks Ed. I'm very curious about the single core speed of Kingsrow 10x10 which is very high. Did you do a simple search? Maybe the game is more tactical and needs a more tactical search, is that it? My spanish checkers engine only does 2Mns in my old pc, while yours does 30Mns. best regards, A...

Sorry I made a mistake by clicking the "Report this post" button instead of "Post a reply", moderation please ignore my mistake. I just want to report a little difference for spanish checkers, all numbers confirmed until depth 11. But starting from depth 12 I have: perft(12) 365,728,331 perft(13) 1,...

What makes it "heavily threaded"? I'm not a native english speaker, so I may not have expressed myself well. I was merely saying the program is very strong with 8 threads. Here in portugal it is not common at all having a 6 core core i7. People who have quad cores are usually from the core 2 famill...

Hi Alvaro. I have a question for you. Please write how to get this program in full version. Krzysztof. Many thanks for you interest in Profound. I'm sorry my friend, but the program is not yet finished. As soon as I finish it I'll contact you, if you drop me an email at deep.profound@gmail.com best...

Hi everyone, It has been going for sometime now a match in the spanish checkers variant between grand master Fernando Silva (Morona) from Peru vs Profound (running with 6 threads on an Intel core i7 3960x), so far 46 games played and the last game was very impressive by Fernando. Only at move 29......

Hi everyone, It has been going for sometime now a match in the spanish checkers variant between grand master Fernando Silva (Morona) from Peru vs Profound (running with 6 threads on an Intel core i7 3960x), so far 46 games played and the last game was very impressive by Fernando. Only at move 29...1...

Thanks, that's what I meant, illegal positions, I'm not an english native speaker.
If only we could find some rules to detect this maybe there could be some gain in the final compressed size of the database.

Alvaro

Hi, while examining Martin Fierz's EGTB compressor, I notice he tried to remove 'impossible positions' to improve compression, but later disabled this code. In the code he commented that impossible positions are positions where there are no unmoves. Have you tried this trick? Is this really safe? An...

Hi everybody :) I'm interested in studying how to implement the "tactics table" concept by Stef Keetman in his thesis. I remember reading it in some chinook paper a few years ago. The idea is to detect a "one for two" exchange, ending up with a checker up of advantage. At leaf nodes this table is pr...

Hi everybody
could you please explain what info does the "draw+ database" has?
Also how many bits are used for each position ?
Is it a single database or two separate ones?
Also what are the advantages over the WDL database?

best regards,
Alvaro

Hi, I had null move in my program Profound (spanish checkers) for some time. But I was getting draws all the time against Triturador. Then at some point I removed it, and implemented some forward prunning of my own. Then Profound started to play better and winning. My implementation of null move had...

Hi everybody :) in my spanish checkers engine I have some hand made tables for passed men, however passed men is a subset of breakthrough tables I think. Could someone please explain how do you automatically generate breakthrough tables? Also what's the max number of attacking men you use to try the...

Hi erveryone :) This is my first post here, I didn't know about the existence of this forum untill a few days ago. I program only the spanish/portuguese variant of draughts (8x8, flying kings, men can't capture backwards). I would like to ask if someone could explain with pseudo code the implementat...