Hi Alvaro,Cardoso wrote:That's what I like in DTW TBs, instant play.
Also at interior nodes, in a win/loss position just returning the DTW value adjusted to the current ply is so simple.
Another really great thing I like is that you can generate a very long pv by probing repeatedly the DTW TB until the final winning position.
All you need is an initial long enough pv that terminates in a position that is on the DTW TBs , and from there you can continue appending the "best" moves found in the TBs, really really great. Sometimes you get spectacularly long pvs even when the root position has several pieces more than your TBs.
You can't do that with WDL TBs only.
What I don't like is poor compression ratio, and to a less extent generation time wich is bigger than WDL TBs.
As I said in another post my first attempt to generating TBs for the portuguese variation of the game was the DTW flavor, only later I did the WDL, so currently I have the 9man WDL (14GB) and the 8man DTW (46GB), all using the leading checker (not rank) subdivision and both compressed and with the option to load them into RAM or using memory mapped files.
I am still writing the access code for searching DTW during the play of the game. Right now all I can do is print out the solutions with my console app.
I did gather some stats.
I have 148,193,593,345 Distance To Win positions solved. This represents all of the 4x4 for 8-pieces + every 7-piece or fewer combination, including 6x1.
There are 25,735 positions that need 16-bits. So I have:
1.000000347315959 bytes per position without using compression.
The lookup is instantaneous though, even faster than the move generator, so my nodes/second will never drop when accessing the uncompressed databases.
I do have some db-9 and db-10 results so far for DTW:
White to move wins in 175-ply
White to move wins in 291-ply. The white checker crowns at the bottom.
I need more storage to continue, so for now I'm working on trying to design the GUI for it.
I'd like to see some of the longest wins in your variant. I'll have to look up the rules for your game and see the differences.