Arasan - Oldie Goldie
If I were to name one of the oldest and most famous and respected chess engines with terminology straight out of Howard Phillips Lovecraft's prose, I would write that Arasan is the one of the Great Old Ones.
Although Arasan is not as old as Cthulhu (one of the heroes of the books of the above-mentioned writer), it takes his rightful and deserved place in the history of chess engines.
Arasan means "king" in Tamil, a language spoken in South India and Sri Lanka.
One of the first published versions was the 16-bit Arasan from 1994, which ran on Windows 3.1.
At the time, there was not so readily available extensive knowledge of chess engine programming. One had to really make an effort to find anything about it on the Internet; assuming there was Internet access at all (in most parts of the world there just wasn't it yet).
What could be sourced were a few mostly academic publications and articles, most of which lacked practical details. Plus there were sources for Crafty, GNU Chess and a few other engines, most of them not very powerful.
And it was in such times that Arasan was created; at a time when the author of the chess engine was literally blazing a programming trail and through his imagination, creativity and determination developed his engine.
Arasan was and is the engine that set the way forward showed how powerful a free, open-source chess engine can be.
It was the availability of Arasan, which I was able to run on a variety of systems and computers (Windows, Linux and Mac) that caused that to this day, Arasan is the chess engine I use frequently.
The author, Mr. Jon Dart, has accomplished a remarkable feat over several decades. Arasan has changed, evolved, used better and better techniques and algorithms.
Whenever another version of it came out, I was sure that I would get an even more powerful and offering more capabilities Arasan. And this was indeed the case.
Arasan is a chess engine that has repeatedly held high positions in various competitions.
Among its many successes, it is worth mentioning:
The winning of the 2012 Americas Computer Chess Championship tournament.
Source: CPW
The winning the World Computer Rapid Chess Championship in 2013.
Source: CPW
Nowadays, Arasan is a very powerful and sophisticated chess engine, using a neural network and rating among the top chess engines.
It is gratifying to see that Mr. Jon Dart is still working on the Arasan chess engine, which is being developed and participating in various competitions, e.g. TCEC, CCRL, MCERL as well as on chess servers, with new versions appearing every year.
Source: CCRL
Below are two examples showing Arasan playing.
#1*
White: Deep Shredder 13, an award-winning, multiple-time chess engine world champion. Shredder is a computer player who for years when he participated in any competition, it was said jokingly and affectionately that no matter what happened in the tournament, Shredder would most likely win.
Black: Arasan 23.4-dev.
A position of sorts: secure the white king and move forward on the Queen's wing.
24.f3
Shredder intends to drive away the intrusive Knight.
24...Nxg2!
Arasan will be so close to the white King is not going to let go.
25...Nh2!
Shredder accepted the sacrifice of a black Knight. Attacked, the black Knight does not intend to make a retreat, on the contrary, it boldly breaks into the ranks of the white King.
28.Be1
White is trying to do everything to protect his King. After this move by White Bishop, can Arasan exert even more pressure ?
28...Rxg2+!!
A monstrously powerful black Rook strike! Shredder must accept this sacrifice.
32...f3
Resolute black pawn approaches white monarch position.
35.Kg1
The White King has finally found protection behind... black's pawn. Is this the end of the Arasan assault?
35...Bf2+! Boom!!
Black sacrifices another figure in order to fly out the white King to tip the balance of victory to their side.
41...Qxc3
Shredder, to avoid immediate defeat, gave away the Queen and Knight, as a result of which he prolonged the game but finally lost.
Deep_Shredder-13_vs_Arasan-23.4.0-43
.zip
Download ZIP • 3KB
#2*
White: Arasan 23.4-dev
Black: BlackCore 6.0, it is a neural network based chess engine developed from scratch. Strength oscillating around 3200 Elo.
Observing BlackCore's play in other games, I noticed that this engine likes to outplay its opponents as a result of skillful mobilization of forces to launch a strong frontal attack.
In this game it also tries to win in this very way.
And, it seems to have a good chance of doing so.
Black's position is dreamed up to launch an assault on the white King.
25...h5
BlackCore is consistently preparing a breakthrough on the g4 square.
Arasan, with calmness, prepares forces for defense.
26.Be2.
26...g4!
This looks threatening and indeed Arasan must play very accurately. In this type of position, the defending side faces quite a challenge; the defense then is more difficult than the attack, as one has to play with maximum accuracy.
28.Bd3
Arasan ties the black Knight.
29.Bxe4!
At the cost of the white Rook, Arasan intends to take the initiative in a position that just a few moves earlier seemed doomed to be arduously defended.
BlackCore carelessly took the white Rook which Arasan takes advantage of.
31.d6!
Bishops Arasan previously "dormant" regain vigor. More and more lines and diagonals are available to whites.
33...Bf8
Blacks, although having a material advantage, lost the initiative and went on the defensive.
34.Bh7+!
White Bishop on a battle rampage!
38.Qd5
The combined Arasan figures are unstoppable. The game is coming to an end.
41.Bf4#
End. The Black Queen, just as she took the white Rook, has not moved since.
An instructive and inspiring game!
Arasan-23.4.0-43_vs_BlackCore-6.0
.zip
Download ZIP • 3KB
How does an engine developed over decades play chess?
Exactly as in the examples above! And this is just a sample of its skills.
Arasan is not the strongest chess engine in the world. But it doesn't have to be one in order to play delightful chess, delight users with its style and be a great computer companion for chess training and learning.
Arasan is one of those "Great Old Ones" - Oldie Goldie - which, thanks to the author's openness and sharing of the source code, have been and continue to be an inspiration to so many chess enthusiasts.
Feel free to visit the download area.
Linux arm64 & x64 – Compiled by Darius
Arasan-23.4.0-43-g5968e0b_Linux_arm64
.7z
Download 7Z • 9.51MB
Arasan-23.4.0-43-g5968e0b_Linux_x64
.7z
Download 7Z • 9.77MB
Mac Apple Silicon & Intel – Compiled by Darius
Arasan-23.4.0-43-g5968e0b_Mac_Apple_Silicon
.7z
Download 7Z • 9.48MB
Arasan-23.4.0-43-g5968e0b_Mac_Intel
.7z
Download 7Z • 9.65MB
Windows x64 – Compiled by Darius
Arasan-23.4.0-43-g5968e0b_Windows_x64
.7z
Download 7Z • 9.73MB
Source Code – created by Jon Dart
Arasan-23.4.0-43-g5968e0b_Source_Code
.7z
Download 7Z • 11.03MB
In the Files area you will find free chess engines for download.
* Diagrams generated in Aquarium program.