New 10x8-engine release: Joker80

[H.G.Muller]

I just put an alpha version of Joker80, which is a Joker derivative dedicated to play on a 10x8 board. For the moment, it can only be used to play Capablanca Chess, as I did not implement the variant or setboard commands yet.

It seems the strength difference between micro-Max and Joker is well preserved in their conversion to Fairy-Max and Joker80, respectively. That makes Joker80 by far the strongest 10x8 WinBoard engine around at the moment.

[GothicChessInventor]

Perhaps in the near future we can test Gothic Vortex 2.2.5 against it in a casual 2-game match. I'm still working on the winboard piece, and I'll have to change the entire time control code for this.

Vortex was not designed for blitz chess. I deliberately have the branching factor "bubble" below ply 10, and "thin out" on plies 10 and up. This allows the program to consider more tactical and very aggressive lines at the root of the tree, then "go deep" to make sure they are sound.

The tradeoff: Too sacrificial at shallower depths, and not reflective of its true strength at longer controls.

I'd hate to have to #define some completely new evaluation function if it is just going to play blitz winboard matches.

[H.G.Muller]

Well, you don't have to support every time control known to man to be WinBoard compatible. WinBoard is just meant as an interface, to request in a standard way the things the engine can do. If there is a WinBoard command 'variant=crazyhouse', it doesn't mean a Chess engine is not WinBoard compatible because it cannot play crazyhouse. Similar with time controls.

I suppose Vortex already has some form of time control. Just be sure that it correctly sets the parameters for that time control from the 'level' command, and consider any other requested time-control modes as a 'quit' command, perhaps after printing an error message (e.g. 'telluser incremental time control not implemented in Vortex').

Like Humans, some engines are better at one time control than at another. That doesn't mean they aren't interesting opponents at time controls they were not tuned for. This is why there are separate rating lists for 40/40' and 40/5' (or even 40/1').

[Uri Blass]

Perhaps in the near future we can test Gothic Vortex 2.2.5 against it in a casual 2-game match. I'm still working on the winboard piece, and I'll have to change the entire time control code for this.

Vortex was not designed for blitz chess. I deliberately have the branching factor "bubble" below ply 10, and "thin out" on plies 10 and up. This allows the program to consider more tactical and very aggressive lines at the root of the tree, then "go deep" to make sure they are sound.

The tradeoff: Too sacrificial at shallower depths, and not reflective of its true strength at longer controls.

I'd hate to have to #define some completely new evaluation function if it is just going to play blitz winboard matches.

I know that in normal chess I could not find a single case with significant number of games when the difference in rating between long time control and blitz is more than 100 elo.

Even finding 2 programs when one is significantly better in 40/4 and one is significantly better in 40/40 is an hard task

The best example that I could find is colossus2007b and frenzee
and even in that case I guess that the programmer of colossus fixed the bug that cause it to perform worse at long time control.

Colossus 2007b 2674 +20 −20 47.5% +16.9 30.1% 890 40/4
Colossus 2007b 2588 +37 −38 46.5% +23.5 31.0% 242 40/40

Frenzee 3.0 2604 −61 +24 −24 48.0% +14.2 27.1% 616 40/4
Frenzee 3.0 2666 +27 −27 51.4% −16.8 33.1% 459 40/40

Uri

[H.G.Muller]

Note that I upgraded the Joker80 on my website to a version (1.1.14 (e)) that does implement 'setboard' and variant gothic. It is a WB protocol-2 engine now, which also implements the 'ping' command. (Seems the 'undo' command does no longer work, though. )

Piece values in this engine differ from those in the previous release, but are still tentative and might need some future tuning, although they are probably not too far off.

[Matthias Gemuh]

Note that I upgraded the Joker80 on my website to a version (1.1.14 (e)) that does implement 'setboard' and variant gothic. It is a WB protocol-2 engine now, which also implements the 'ping' command. (Seems the 'undo' command does no longer work, though. )

I herewith confirm that Joker80 plays its variants fine in ChessGUI.

Matthias.