and if possible
answer the questions you are willing to answer.
Chess 2010 introduction
Recent developments in computer chess
Other expert opinions
Chess 2010 opinion poll
Chess 2010 matches
This is a short recompilation of a big (and quite technical) discussion that recently took place
in a public chess forum on Internet which was started by REBEL's programmer Ed Schröder.
Schröder pointed out that making a chess program to perform better in the computer-computer
area doesn't necessarily mean that the program automatically will play better against
As a matter of fact Schröder believes there is even a great risk that the opposite
might come true and that chess programs only become better in the computer-computer area but
will lower in strength against humans.
Schröder noticed that adding more tactical power to his chess program REBEL, this in return
for taking out existing chess knowledge, made REBEL a stronger computer-computer player but
also that REBEL's positional understanding lowered because of the lack of the chess knowledge
that was removed.
This phenomenon is not new. Hans Berliner programmer of the famous HITECH
program already pointed this out some 15 years ago. He more or less proved that chess
knowledge (in computer-computer play) is only worth just one extra ply.
The BERLINER experiment
Berliner took the Hitech program, removed important chess knowledge but left the very basic
chess knowledge and called this version Hitech_Low (HL) and his original version
Then computer-computer matches were played with HL and HH at several ply-depths.
It showed up that HL (8-ply) lost from HH (8-ply) because HH was a much more intelligent
program than HL, but that HL (9-ply) vs HH (8-ply) was already about equal and
that HH (8-ply) was crushed when it played HL (10-ply)!
The conclusion more or less was: (extra) chess knowledge is just worth one ply in the
computer-computer area. The advantage of HH having much more chess knowledge than HL
wasn't enough to survive against a program with only the very basic chess knowledge
searching 1-1½ ply deeper.
Recent Computer Chess developments
Especially the last years ideas based on the BERLINER experiment have been
practiced in chess programs with extremely good results in the computer-computer
area. Chess programmers discovered that by a new approach that looks illogical
at first sight their programs became a lot stronger in the computer-computer area.
Computer chess development of the last years:
Schröder about this new trend:
- Make the program as fast as possible.
- Even remove existing chess knowledge to ensure a fast chess program.
- Add lots of tactics to out-search the opponent.
- Add only the very basic chess knowledge (Berliner concept)
- Make the program aggressive to ensure tactics in games.
It's my opinion it all seem to work in the comp-comp area.
Now for comp-comp lovers this is great news but what about the people
who use a chess program for analysis, study and playing games?
10 days ago I released Rebel10.0c as an engine update for Rebel10.
In 10c I removed some chess knowledge which made Rebel 30% faster, next this 30% speed
gain was used to add new tactics. As a result 10c is a better comp-comp player
now but a lower positional player than the original Rebel10.
This is actually what is happening the last years and I want to report
it in all its details in the hope it will be understood.
There are advantages and disadvantages. The advantages are for the
comp-comp lovers. The disadvantages are for people who use a chess
program for analysis, study and playing games as the positional
understanding of chess programs will drop and no progress is made.
My personal opinion is that the disadvantages are bigger than the
advantages because the vast majority of people that use a chess program
use it for playing games, analysis and study.
It's my wish the computer chess press will pick up the subject, explain and judge.
Other expert opinions
Several other colleagues of Schröder joined the discussion and gave their opinion.
Robert Hyatt, programmer of Cray Bitz and Crafty:
There is an alternative. Do as I try to do... Ignore computer vs
computer games unless you see something you are consistently doing wrong
in those games.
I'm not hung up on trying to beat every program by
being as fast as possible. I have gotten _slower_ the past 3 years, not
faster, and I think that direction is perfectly ok. I've said before
that _far_ too much attention and emphasis has been placed on SSDF
results, which has led to today's situation.
I think it much more interesting
to continue what I've been doing for along time: trying to find ways to make
these 'anti-computer' strategies backfire. Because once you learn how to
'break anti-computer' you also learn how to _play_ it. And there would be
nothing to prevent you from using that against other computers, of course. :)
Bruce Moreland, programmer of Ferret:
Responding to Ed's original post
I have considered these issues carefully. My own goal is to create
something that is interesting and strong, and I'm not going to gut my
program's style just to get an extra quarter ply to use against
I think that in the long term a good eval function is necessary to
avoid catastrophic mis-evaluation of crucial features, against both
humans and computers.
I avoid things like the Swedish list, in part because they've never
invited me to send a version, and in part because I don't want to get
sucked into that whole core-wars deal.
I would much rather be ranked on the FIDE list, which is where every
player really belongs.
In Paderborn, assuming I am selected to go, I will be competing with
something that will also play, with no modifications, against the
humans on ICC, which is how I've always done it.
A link-list of interesting postings on REBEL-BOARD concerning the topic.
As a result of the above Rebel company feels that something need to be done for the
future to ensure progress in both areas (Man vs Machine and Computer vs Computer).
To reach that goal CHESS TIGER programmer Christophe Théron from now on will
only focus on computer-computer programming and make his program (if possible) the best
computer fighter around.
It's our understanding that although in minority many people are in love with computer
vs computer play and we want to keep serving them.
REBEL programmer Ed Schröder will concentrate to make his chess program an
even better positional and human-alike chess player and make REBEL an even more
attractive and configurable chess engine.
Doing so we believe we can serve the chess community best as progress is guaranteed
in both areas.
For more information about the REBEL-TIGER approach
Because of the importance of the subject we invite you to have a look at the
CHESS 2010 POLL
Results of the CHESS 2010 opinion poll are published
HERE so everybody is able to give their view.
CHESS 2010 matches
This is a new computer-computer event called CHESS 2010. The goal of CHESS 2010
is to give a preview of what one may expect from chess programs in the year 2010 concerning
their playing strength in the computer vs computer area.
The idea is to play automatic games between a few top chess programs on the very high time
level of one hour per move average. It's estimated that one game takes 5-7 days to
Rebel company is offering 3 autoplay pairs (6 PC's) for this experiment the coming months
to ensure a reasonable amount of games. The machines used for the experiment and other
- 4 identical Pentium-II 266 Mhz with 64 Mb Ram.
- 2 identical Pentium-II 450 Mhz with 128 Mb Ram.
- Programs will play on their default (or strongest) settings.
- Programs will use the maximum hash table setting possible.
Results so far:
- Rebel10.0c (anti-GM=off system Tiger=off)
- Fritz 5.32
- Junior 5.0
- Shredder 3.0
- Crafty 16.6
- Hiarcs 7.0
- Nimzo 99
Database:CHES2010 *** Top 40 perc. ***
Name Tot Score + ½ - Perc
1. Rebel10.0c 9 5.0 - 4.0 2 6 1 55%
2. Hiarcs 7.0 4 2.0 - 2.0 1 2 1 50%
3. Shredder 3.0 2 1.0 - 1.0 0 2 0 50%
4. Junior 5.0 1 0.5 - 0.5 0 1 0 50%
5. Fritz 5.32 2 0.5 - 1.5 0 1 1 25%
Download games in REBEL format including analysis.
Download games in CBH format including analysis.