Winboard Forum

AliBaba 1.0wb JA by Dennis Breuker
http://www.xs4all.nl/%7Ebreukerd/chess/index.html
http://cap.connx.com/Alibaba/

Chess Engine: AliBaba
Author : Dennis Breuker
Version : 1.0wb JA
Date (orig) : 24th Jan 1995
Date (mod) : 31st Dec 2008
Platform: : Windows
Compiler : Msvc++ 2008

I've finally added basic winboard protocol support to this old
chess engine (1995) which was written for testing various hashing algorithms.

Although Dennis Breuker wrote AliBaba as a testbed program, I'm pleasantly
surprised by how well it can play as a proper chess engine. I estimate it's
strength level around 1700-1800 elo, so should provide a challenging game to a
club-level strength human player.

Tested ok in Arena and Winboard chess interfaces and can use gui opening books.

Changes:
-------
1. Added Winboard protocol support.
2. Fixed castling bug.
3. New logo.


ToDo:
----
Add better time-controls. (probably)
Fix bugs that I've missed. (definitely!)

Download:
http://www.mediafire.com/?2rmjn2zqawn


Jim Ablett

Update:

AliBaba 1.1wb JA by Dennis Breuker

Changes (1.1wb):
-------
1. Added better (clock-based) time control
2. Fixed reluctance of AliBaba to castle by adding big bonus incentive to the eval.
3. Increased hash table size to 40mb
4. Level and draw offer winboard commands added.
4. Tweaks to the evaluation.

http://www.mediafire.com/?zwzljnrkyxl

Jim.

Jim, perhaps a bit off topic, but triggered by the fact that you mention hash size.

Are you aware that the latest WinBoards support a memory command meant to set the hash-table size through WB protocol? It is sent before every new command, based on the default setting for hash + EGTB cache size the user entered in WinBoard (stored in the winboard.ini).

There is thus no reason to equip engines with a fixed hash-table size; you can have them send feature memory=1, and WB will then send memory N (with N in megabytes) to inform the engine how much memory it is supposed to use.

As you fix many WB engines, it would be a big boon to the user-friendliness of WB engines if you could equip every engine you fix with the memory feature. (And perhaps the egtb-path feature, where applicable).

Even if the structure of the engine would make it impossible to make it change its hash-table size while running, it would still be very helpful if it would react to the first memory command. Users are not expected to alter the hash size that often. The recommended procedure would be to delay the engine initialization until after having sent all the feature commands, and checked for the accepted or rejected replies from the GUI. If the sengine receives an accepted memory, it is then safe to wait for the memory N command before having the engine do anything else, as WB protocol guarantees that it is the first thing that will be sent after the processing of the features has finished. After it has received the memory command (and perhaps egtpath, which will come after it), the engine can then do its usual initialization.

H.G.Muller wrote:Jim, perhaps a bit off topic, but triggered by the fact that you mention hash size.

Are you aware that the latest WinBoards support a memory command meant to set the hash-table size through WB protocol? It is sent before every new command, based on the default setting for hash + EGTB cache size the user entered in WinBoard (stored in the winboard.ini).

There is thus no reason to equip engines with a fixed hash-table size; you can have them send feature memory=1, and WB will then send memory N (with N in megabytes) to inform the engine how much memory it is supposed to use.

As you fix many WB engines, it would be a big boon to the user-friendliness of WB engines if you could equip every engine you fix with the memory feature. (And perhaps the egtb-path feature, where applicable).

Hi Harm,

I have been following developments, but I didn't think to implement the latest protocol features.
I'm still working to improve AliBaba a bit more so I will definitely try to add the new protocol features in next release,
and other engines I work on in the future.

Many thanks also for the fantastic work you're doing on improving Winboard.

Jim.

OK, Great!

And a happy 2009!

AliBaba update:

AliBaba 1.2wb JA by Dennis Breuker

Changes (1.2wb):
-------

1. Added piece square eval tables for each piece.
2. Small adjustments to time control
3. Fixed possible castling problem.
4. Implemented the new Winboard protocol command 'memory'.
With the latest Winboard versions it is possible to set the hash size for the
engine from within the gui.

Allowed hash sizes in AliBaba >

3mb 6mb 12mb 22mb 32mb 84mb 164mb

If other hash size is selected AliBaba will choose hash size
which is closest in range >
e.g if 50mb is selected in Winboard, AliBaba will set the hash size to
the nearest it will use, 32mb.

If memory command is not used, or AliBaba is used in another chess gui which
doesn't support the 'memory' command such as Arena, AliBaba will used the default
hash which is set at 32mb.

Download:
http://www.mediafire.com/?2zkmyw00w3g

Jim.

Update:

Changes (1.3wb):
-------
Bad checkmate bug fixed. (AliBaba would crash if checkmated.)

http://www.mediafire.com/?ymmmigfzgjh

Jim.