Great day - today :) RubiChess, one of the strongest free (open source, GPL-3.0 license) chess engine has been released in the latest version. According to author Mr. Andreas Matthies, the RubiChess-20220813 is about 20 Elo stronger than the previous version! (compared to 20220223). Here's a list of changes and new features in the latest RubiChess: " ChangeLog ========= 20220813 (release 2022-08-13) : - Time management improvements: + Plays movetime mode respecting move overhead + More flexible time usage depending on nodes spending on best move + Plays very short time controls like 1+0.001 without time forfeits now + Better support for nodes based time control + Avoid getting low on time in moves/time control - New default network nn-b1c332ae1d-20220613.nnue - Improve endgame draw detection when playing withou tablebase - Contempt (default 0) and rating based contempt (triggered by GUI using UCI_RatingAdv) - Improved logging ('..._app' for appending, '..._pid' for concurrent loggin using the process id) - Speed improvements (1-3% on x86, > 10% on Arm/Neon) - Several fixes " Source: GitHub Estimating an increase in the strength of the latest RubiChess engine by 20 Elo, it is prudent to assume that it will consolidate in the top ten engines. Source: CCRL August 13, 2022 Chess engine enthusiasts will be pleased to know that the RubiChess engine can be easily compiled for all popular architectures. Many thanks to the author of the engine Mr. Andreas Matthies for such a possibility ;) Feel free to download RubiChess. Compilation for Android made by Archimedes. Thank you very much! Compilation for Linux (ARM & Intel) made by Darius. Compilation for Mac (Apple Silicon & Intel) made by Darius. Compilation for Windows made by Mr. Andreas Matthies.

I am pleased to introduce the Velvet chess engine for the first time on chessengeria news. Source: GitHub It is very strong open source chess engine, written in Rust, licensed under the GPL v3.0. Compilations by Mr. Martin Honert. Velvet is a "young" chess engine, whose first public version (v1.0.0) was released in August 2020, playing at around 2500 Elo. Here is one of the older versions of Velvet-1.2.0 -> compilations for Mac's by Darius. Velvet author Mr. Martin Honert spent the next 2 years dynamically developing his engine, which became stronger and stronger. Source: CCRL The previous version of Velvet 3.3.0 in a 100-game match against Fritz 18 Neuronal lost the match, which ended with a score of 63 to 37 for Fritz. Attached are 100 games of a match between Velvet 4.1.0 against Fritz 18 Neuronal. Each engine had 4 CPU at its service and 1 minute per game; Fritz 18 GUI, 128 MB hash table and Perfect 2021 opening book. This time, the match ended with a score of 51 to 49 for Velvet ! Extremely fierce duel between two strong and modern engines, very many resultant games. It was a pleasure to watch this struggle :) I present one of the many interesting moments of the match. It is worth noting the evaluation of the position by both chess engines. I encourage you to watch the games of this match. It is worth mentioning that Fritz 18 Neuronal is an opponent worthy of even the strongest engines, having won the title of World Chess Software Champion in 2022 (the Komodo Dragon chess engine, among others, participated in this competition). What certainly distinguishes the Velvet chess engine is its dynamic - even aggressive - style of play, which, combined with efficiency and high playing power - can appeal. When playing, Velvet does not hesitate to sacrifice material in order to gain the initiative and lead the attack. It is unusual for Velvet to play spectacularly also against very strong opponents, who will not pass up any opportunity to score a victory. On the Stefan Pohl Computer Chess website, Mr. Stefan maintains an interesting ranking that shows the results of measuring the playing style of chess engines by measuring their aggressiveness. The Velvet engine is at the top of this ranking! Here are the top ten: Source: Stefan Pohl Computer Chess If you are interested, I encourage you to visit this site for details. From myself, I would like to add that the author Mr. Stefan Pohl is doing a fantastic job, sharing its fruits with the entire community of computer chess fans. Thank you! Below is a sample - few stages of that game - of the playing style of the Velvet chess engine in a game against the Hiarcs 15.1 engine (~3300 Elo). 1 minute per game for each, 4 CPU at its service, 128 MB hash table and Perfect 2021 opening book. Hiarcs Chess Explorer Pro GUI, MacBook Pro M1. I have left in notation the times the engines took to make their moves. 13.h4! Velvet launches an attack, giving up a pawn on the b2 field. 17.g4 Hiarcs after his previous move 16...Qa3 evaluated the position as perfectly equal (0.00). Velvet sacrifices another white pawn (c2) judging the position to be more favorable for white. 20.f4 Velvet launches another pawn, including it in the attack on the black king's position. The material advantage of Hiarcs is already two pawns. Velvet assesses his - white's - position optimistically at 1.83. Hiarcs does not yet see much danger, assessing the position after his last move at 0.78. 23.f5 Hiarcs had, in several previous moves, led to the removal of several figures from the chessboard - still evaluating the position on the chessboard as equal with a minimal point in favor of white. Velvet, after moving the pawn to an even closer position of the black king - on f5 - assesses his position as won. 26.Qxh7 Velvet comes close to dealing the final blows to her opponent. Hiarcs engine figures as paralyzed on their starting fields - black rook on field a8, black knight on field b8, black queen moved away from the center of events. 28.Nf4 Hiarcs can only look on at this. Nothing can save black anymore. 33.e6! After several more moves Velvet wins, Hiarcs resigns.

A new version of Hiarcs Chess Explorer Pro is now available. Source: Hiarcs Here's what version 1.1 brings: " New HIARCS 15.1 engines with improved strength and multi-core support Updated 2022 opening books Updated 2022 MasterBase database Improved Annotation display Improved support for ChessBase CTG books Improved support for Unicode and figurines in ChessBase CBH databases Improved copy and paste functions Improved export to EPUB Engine match enhancements New language translations Auto recovery of databases after restart Skip duplicates with different names or results Show existing comments in Puzzle mode Numerous other fixes and enhancements " Website: hiarcs.com Download: developer's webpage The Hiarcs 15 engine is doing very well in MCERL competitions. Soon I will update the MCERL ranking list and broadcast a match/tournament featuring the new version of the Hiarcs engine. If you haven't read it yet, I invite you to check out the Hiarcs Chess Explorer Pro review.

I open the latest edition of the Mac chess engine ranking list - MCERL :) Free chess game viewer from ChessBase. The title queen sacrifice comes from one of the chess games played in the MCERL series between Hiarcs 15.1 and Stockfish 15. Another ranking list, another chess engines that joined the struggle on 64 fields. MCERL includes not only the strongest and latest engines. Recently released engines as well as the established, titled ones also take part in the struggle. Thanks to excellent authors and enthusiasts, we have the opportunity to enjoy the game of many interesting chess engines. In this edition of MCERL, I would like to extend warm thanks to enthusiasts of this topic such as Alessandro Morales for his many excellent compilations of chess engines, and Stefan Pohl and Thomas Plaschke for providing a tool called: Sacrifice Games Search and Statistics Tool on the Stefan Pohl Computer Chess website. Gentlemen, thank you sincerely for the excellent fruits of your work ! I invite you to take a look at the latest MCERL.

You are cordially invited to read the latest edition of the MCERL rating list. A screenshot of Hiarcs Chess Explorer Pro 1.1.2. In this release a big surprise: Revenge, Houdini, the eponymous Deep Junior and other 64-bit Windows chess engines - playing on a MacBook Pro M1. And the results... thought-provoking. Enjoy :)

Very strong UCI open source chess engine by Kieren Pearson, written in C++, licensed under the GPL v3. It is likely that the development of this chess engine will no longer be as spectacular as before.... Hopefully, the project will continue to be developed. CCRL: 2022-10-16 Competing in the Mac Chess Engine Rating List (MCERL of 2022-10-15), Halogen 11 achieved an excellent rating: 3445 Elo. Here is what author Mr. Kieren Pearson wrote for the eleventh edition of Halogen. " I am pleased to release Halogen 11. Halogen has been an ongoing passion project of mine for the better part of a decade. I view it as one of my greatest accomplishments and look back with fond memories of the time I spent tinkering, experimenting and debugging. It was always a dream goal of mine to complete at the highest levels of computer chess, including competitions such as the TCEC and CCC. Sadly, I no longer have the time to continue working on Halogen with the pace that I once did. I am not abandoning the project, and will continue to add occasional tweaks and improvements, as well as accept contributions. " Source: GitHub Halogen plays in a not-so-ordinary style. In gratitude to the work of its author Mr. Kieren Pearson, I am posting downloadable compilations of this remarkable engine for all popular platforms. Android - Compiled by Archimedes Mac - Compiled by Darius Linux - Compiled by Kieren Pearson & Darius (ARM64) Windows - Compiled by Kieren Pearson

Berserk, a top chess engine. On October 4, 2022, the 10th version of this engine was released. Berserk is among the top of the most powerful chess engines. The first matches show a marked increase in Berserk-10's strength over its predecessor. The results of the ranked games in the MCERL section are coming soon. Ranked games in progress... :) GUI: Banksia If you want to learn more about this engine, I invite you to visit the page dedicated to the Berserk chess engine. Here's what author Jay Honnold wrote about new Berserk 10: Small Endgame Eval Patch by @jhonnold in #387 QSearch TT Exact Results by @jhonnold in #388 Disable late move pruning at root + improve ordering by @jhonnold in #390 Adjust History Formula by @jhonnold in #391 Corrent singular search results by @jhonnold in #392 Reverse Futility Pruning Margin Tweak by @jhonnold in #393 PGO for Update Script by @jhonnold in #394 Remove History Pruning by @jhonnold in #395 Remove Counter History Pruning by @jhonnold in #396 1024 Hidden Neurons by @jhonnold in #397 RFP and Razoring Tweak by @jhonnold in #399 EP square only when viable by @jhonnold in #400 Return to 512 Hidden Neurons by @jhonnold in #402 Separate promotions in tactical history on captures by @jhonnold in #403 Accumulator update via Move by @jhonnold in #404 Reduce more in NMP when there are no opponent threats by @jhonnold in #405 Don't reduce more for previous PV moves by @jhonnold in #407 Improve NNUE auto-vectorization and update logic by @jhonnold in #408 Simplify NNUE Code by @jhonnold in #409 16 King Buckets by @jhonnold in #410 Improving flag via GrandParent nodes. Adjust LMR to use a new formula + legal moves. by @jhonnold in #413 Fix hashmove reference in code by @jhonnold in #414 Berserk 10 download: Compiled by Archimedes Compiled by Darius Compiled by Jay Honnold

Strength of about 2800 Elo. A growing chess engine, author Mr. Pawel Osikowski. Inanis is a free and open source UCI chess engine written in Rust. Licensed under GPL 3. It is the successor of Proxima b, Proxima b 2.0 and Cosette. Here are a few words from the author about the Inanis chess engine: " The project is written after hours, with the goal to reach a strength of 3000 Elo. Perfect as a sparring partner for other chess engines, since it was heavily tested using very fast games. Supports Syzygy tablebases, MultiPV, pondering and multithreading. Inanis 1.1.1 changelog: Added support for FEN property in PGN parser and "tunerset" command Replaced crossbeam package with native scoped threads Fixed invalid handling of "isready" UCI command during a search Fixed engine crash when trying to search invalid position Fixed incorrect version of toolchain used in GitHub Actions " Inanis is a superbly documented chess engine; details posted on this page and this page. I am sure that soon Inanis will reach a strength of 3000 Elo and I hope that Mr. Pawel Osikowski will continue the further development of this interesting chess engine. I invite you to download Inanis. Android – Compiled by Archimedes Linux – Compiled by Pawel Osikowski Mac Apple Silicon & Intel – Compiled by Darius Windows – Compiled by Pawel Osikowski

MadChess is an UCI compliant open source chess engine by Erik Madsen, written in C#. Licensed under the MIT License. MadChess is one of the few chess engines to run under the Windows .NET framework. Since version 2.1, MadChess uses .NET Core, Microsoft's cross-platform free and open-source managed software framework, to support not only Windows, but Linux and Mac. It is a very well documented chess engine. If you are interested, I encourage you to visit the dedicated page. Update 2022-11-16 Courtesy of the author, Mr. Erik Madsen, I am providing a link to download the latest version of MadChess-3.2 Beta for Windows. To quote the author, in the latest version, "improvements have been made to the strength-weakening algorithm". Of course, this one will apply when MadChess-3.2 Beta is configured by the user to play with a defined strength expressed in Elo points (details later in this post). After playing 380 rated games under MCERL (ongoing), MadChess-3.2 Beta has reached a ranking 2785 Elo. According to the CCRL rating lists, MadChess-3.1 has strength 2719 Elo, which is equivalent to the strength of a very powerful grandmaster. Source: CCRL Based on my observations of MadChess in MCERL competitions, this engine plays interesting and dynamic chess. He is able to find fantastic tactical punches in short time. Below is the position from the game between Crafty 25.3 and EXchess 7.97b. In this position, Crafty "missed" a very strong move by the white pawn to the e5 square. MadChess-3.1 analyzing on a MacBook Pro with an M1 processor took less than one second to find 33.e5! Fen: 4r1rk/2qbbppn/3p4/1p1P3P/2p1P3/PpP1B1R1/1P2Q2N/1B4RK w - - 3 33 Particularly noteworthy is the ability to customize the strength of MadChess-3.1. On his page, author Mr. Erik Madsen described and showed with examples (Hiarcs Chess Explorer & Shredder) how to make changes to the MadChess strength. It is worth mentioning that the range of power adjustment is quite wide: 600 Elo to 2400 Elo, that is, suitable for a chess learner through a club player to an international master. Below is an example from Banksia GUI with MadChess Elo set to 2000. Here are the messages of Madchess-3.1 reporting readiness to play. Feel free to download MadChess-3.1 Linux ARM – Compiled by Darius Linux Intel – Compiled by Darius Mac Apple Silicon – Compiled by Darius Mac Intel – Compiled by Darius Windows – Compiled by Erik Madsen

Chess engine developed for more than 20 years! In its time, it was one of the most interesting chess engines using advanced search algorithms. He played against the best and won against the best. Interesting style of play, characterized by consistency and tough defense, more of a strategist than a tactician taking advantage of his opponent's stumbles to gain a better position/initiative and turn it into a win. EXchess is open source chess engine by Daniel Homan, written in C++, released under the GNU Public License. Playing power between 2900 Elo (1 CPU) and 3000 Elo (4-CPU), which means that even today it can be used to analyze human chess games at a pretty good level. Source: CCRL The last version was released in 2017. Today somewhat forgotten, and not rightly so. With this post I'd like to refresh a bit the memory of EXchess, an unexceptional chess engine, which is worth running sometimes to enjoy its gameplay again. I have also collected EXchess compilations for several platforms, adding self-compiled versions for modern Macs. Below is an example of EXchess' style of play and its effectiveness. Crafty with white, the legendary chess engine by Professor Dr. Robert Hyatt, in its latest and most powerful version. EXchess with black. Let's look at the placement of the pieces on the chessboard. * Fen: 4r1rk/2qb1ppn/3p1b2/1p1P3P/2p1P3/PpP1B1R1/1P4QN/1B4RK w - - 5 34 Dream position for Crafty, who has worked out great attacking possibilities: heavy figures on the g-line, Bishops looking directly at the black King's position, just a move with a pawn to the e5 field to completely open the positions, the black Queen away from his King with no possibility of a quick defense. In this position, Crafty played 34.Bh6? Unfortunately, this move is not a good one. The best continuations would have been created after playing 34.Bd4 or 34.Nf3. Even the immediate 34.e5 led to a better game for white. EXchess exploits Crafty's mistake by playing the unexpected 34...Bh3! This move, which is not easy to find, disorganizes white's assault on the black king's position. EXchess equalizes the game with one move, though. Crafty doesn't realize it yet. After several exchanges, EXchess plays 37...Be5 an important move from a strategic point of view, which in practice takes the white Bishop out of the game. A few more moves and another "quiet" success for EXchess, which further reduced the material on the chessboard. This is to his advantage, because Crafty, although in possession of the white Bishop, is stuck on the b1 square. Crafty feels confident enough to even allow the exchange of Queens. EXchess understands the positions on the chessboard perfectly. Each successive exchange and reduction of material increases it chances more and more due to the excluded white Bishop still standing on the B1 field. 41.Nxe5?? Blunder that will cost Crafty a loss in this game. "The dust has settled". EXchess after disorganizing white's attack, blocking Bishop on B1 and favorable reduction of material - has a completely winning position. Crafty is still trying desperately to turn the game around, but they are already doomed to failure. Downloadable game in PGN format A great game without spectacular sacrifices for the fact that it contained interesting startegies from both sides! In the first phase of the game, Crafty strenuously built up its lead despite the lack of clear blunders on Exchess' part. And then, making his 34th move, Crafty played a seemingly winning move. 34.Bh6 would have been excellent, had it not been for EXchess' magnificent counter move of the black goon 34...Bh3! After that, things moved quickly. It only took 7 consecutive moves for Exchess, taking advantage of Crafty's blunder and his wrong strategic decisions, to lead to a complete collapse of white's position. Feel free to download the EXchess. Android – Compiled by Jim Ablett Linux ARM & Intel – Compiled by Darius Mac Apple Silicon & Intel – Compiled by Darius Windows – Compiled by Daniel Homan * Diagrams generated using Hiarcs Chess Explorer Pro.

Free, under the GPL 3 license with access to the source code. Sting is a chess engine based on one of the earlier versions of Stockfish 2.1.1 (released in 2011). Sting can... sting... very aptly. The author, Mr. Marek Kwiatkowski, has been developing Sting for many years into a tool for, among other things, solving very difficult chess problems, better understanding of uncountable positions (i.e. positions that even modern engines running on the most powerful computers cannot solve correctly), pointing out the most accurate moves / ideas related to the creation and overthrow of so-called chess fortresses. In the ranking lists, the latest versions of this engine can be found in vain. The author's goal was to systematically increase the "IQ" of this engine as a problem-solving ability rather than strength. Source: MCERL (ongoing) As part of the MCERL ranking games, I decided to give the latest version of Sting a chance. After playing 308 games, the Sting SF 28 AI achieved a ranking of 3151 Elo. Is it a lot or is it a little ? If we compare the strength of Sting with that of Stockfish 2.1.1, on which Sting is based, it comes out that Sting is stronger by 59 Elo points. Source: CCRL And compared to the latest official version of Stockfish 15, the difference already reaches several hundred Elo in favor of Stockfish 15. The feature that sets the Sting engine apart is its efficiency in solving problems that state-of-the-art chess engines cannot cope with. Here are some examples of positions in which the modern chess engines fail. Test platform: MacBook Pro M1, Hiarcs Chess Explorer Pro GUI, 7 Threads and 1GB hash table for Sting chess engine. Position #1, white's move, draw. We start with something simple for humans, but not at all obvious for chess engines. White has a material advantage in the form of Bishop. Despite this, the position is equal and should be judged as such by chess engines. Sting found the correct move immediately and came to the correct position evaluation after 3 seconds to think. Position #2, white's move, draw. Here we already see a much more difficult setup on the chessboard. White can achieve a draw despite the fact that black will obtain the Queen. Sting "sees" the correct continuation 2 seconds after the start of the analysis. Position #3, white's move, white wins. And here is a position that has remained unsolved by chess engines for many years. Extremely high level of difficulty. The solution is "unintuitive" and requires a lot of maneuvering before promoting the pawn to the Queen. Most modern engines, after starting to analyze this position, are unable to find the correct solution or take hours to reach a solved. Sting takes three minutes to find the right first move and four minutes to pinpoint the continuation leading to white's victory. Position #4, white's move, draw. Probably a position of the kind most difficult for chess engines. White has the loss of having a weaker figure (Bishop instead of Rook) and cannot avoid further material losses. A draw is possible by setting up a so-called fortress. White can set up a fortress by making various moves, while the result will be the same: a draw, as black will not be able to overthrow the fortress despite a large material advantage. As of the date of this post, only the Sting SF 28 AI chess engine was able to show that white could achieve a draw in this position. The position into which the whites fortify themselves looks like this: Sting can... sting by pointing out solutions improbable to humans and even more improbable to some chess engines. I am sure that Sting can be a great addition to the chess workshop as a chess engine for special tasks. I would like to invite you to download and test Sting SF 28 AI in the most difficult and interesting chess positions. Android – Compiled by Archimedes Linux ARM & Intel – Compiled by Darius Mac Apple Silicon & Intel – Compiled by Darius Windows – Compiled by Marek Kwiatkowski

The new chess engine Neuromancer 1.0 is an interesting proposition for people who want to play with a computer partner of the strength of an average club player. The author of the engine is a programmer with nickname mateog03, who writes about his engine like this: " (...) I expect it to be at least 1650, maybe more. It is original, quite short (less than 1300 LOC) and written in C++20 for portability (you need the pthread library though). it's a classic alphabeta engine with an evaluation that consists of only mobility and king safety. it compensates the lack of features with speed and sometimes it draws completely winning positions by repetition, so there's that. "