Computer Chess Club Archives




Subject: Elephant 1.00, a new winboard engine

Author: Harald Lüßen

Date: 17:04:17 03/15/04


This is the first public release of my new chess engine Elephant.

Elephant 1.00 (20040315)
A winboard chess program
(c) 2003-2004, Harald Luessen, Hamburg, Germany
All rights reserved

This is a Winboard II engine. I can use it under Winboard, under
Arena and even as a console program. Please try to play with it
use it in tournaments and send me comments if it does not work.
Please tell me if you like it, too. ;-)

I just sent it to RWBC
and to the WBEC Ridderkerk homepage
I hope it will be accepted.
Where else should I place it when I have no own home page?


Elephant is a Windows program. I put the engine file elephant.exe
in two folders when I play with winboard. I write in the
winboard.ini file something like

"gnuchess xboard"
"elephant xboard" /fd "elephant_100\bin1"
"gnuchess xboard"
"elephant xboard" /sd "elephant_100\bin2"

The engine will write a file elephant.log in its current
directory. I use about 150 MByte of RAM.

About the program:

- Written in Ms Visual C++
- Winboard II compatible
- Bitboard board representation
- PVS search engine
- No opening book
- 128 MByte Hash Table (sorry, no configuration so far)
- Pawn & king hash table
- Adaptive Null move pruning
- Internal iterative deepening
- History heuristic
- Killer heuristic
- Static exchange evaluation
- Move ordering
- Quiescence search without checks
- Evaluation of material, pawns, king safety, piece squares,
  mobility and more
- Lazy evaluation
- Some extensions
- Razoring, futile pruning
- Very simple time management
- One thread for the engine, one for stdin


This is my third chess program. The first was written in
GFA-Basic and never played well. The second was written in C
on the Atari ST and it was working, but very slow. It was never
released to the public. Then there was a pause of more than 10

I began programming this engine in August 2002, when I found
bitboard explanations in the german chess magazine "Computer
Schach und Spiele". I can only work on it in the evening or
weekends and there are other hobbies too.

I learned a lot from the book "Schach am PC" including the
Minimax engine. Other origins of my knowledge and inspiration
is the internet and usenet. I have to thank Bob Hyatt, E. A.
Heinz, Bruce Moreland, Tim Mann and many others who write about
their ideas and algorithms or publish the source code of their
engines. But the Elephant is my own work and it is no clone of
any engine! I have a history of nearly 100 zip files of self
made source code. I think I will publish parts or all of it
when the most embarrassing errors are fixed. I have no home
page yet, may be I ask my brother.

The Name Elephant:

The first working title was cbitboards and the files are named
bb_*.cpp. I needed an international friendly unused name for
the engine and I chose Elephant because it can be personalized,
it refers to my weight, elephants are known to be intelligent,
they can be visualized as rooks on the board and I have seen
the impressive animals in LOTR 3.


Please use a Winboard GUI or Arena. I don't recommend the

How strong is Elephant?

I don't know. In my few tests it is a little bit weaker than
GNUchess but sometimes beats it. It is too slow. On my Pentium 4,
2.6 GHz it says in the opening position:

depth=10 +0.11 Ng1-f3 Nb8-c6  d2-d4  d7-d5  e2-e3  e7-e6
               Bf1-d3 Ng8-f6  Nb1-d2 Nc6-b4   O-O  Nb4xd3
Nodes: 1822113 NPS: 186691
Time: 00:00:09.76

The evaluation features and weights and many other technics
are implemented ad hoc and not tested very much. There is much
room for improvement.


- Bugfixes
- Tests and improvements
- Opening book
- Play on internet chess servers (?)
- Better time management
- EGTB (later)
- ?
- Patient testers and supporters are welcome

The Author:

I am Harald Lüßen. I live in Hamburg, Germany. I am born 1964.
As a software developer I build car navigation system databases.
I have not played more than 50 real chess games in my life and
I don't know whether I am a reasonable chess player or not.
I don't have ELO ratings. I don't have or play with new
professional chess programs. But I like to build own chess
programs. I do this with every new programming language I want
to learn. ;-)

Mail to:

Have fun


This page took 0.01 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.