Season 17 featured for the first time two separate leagues, one for GPU -based engines and one for CPU -based engines. In keeping with its identity as a competition run at long time controls on high-end hardware,   TCEC secured a hardware upgrade for the competing CPU engines.
For CPU engines, there will first be a Qualification League consisting of 16 engines, followed by League 2 16 engines and League 1 16 engines. In the Qualification League the top 6 engines promote.
In League 2 the top 4 engines promote. The engines in each league are seeded based on their performances in previous seasons. For GPU engines, there will be one league only, with up to 16 competitors.
Premier Division is also expanded from 8 engines to Finally, the top two engines in Premier Division qualify for the game superfinal match.
After not competing for five seasons, Season 11 Div 3 engine Defenchess trailblazed the qualification league. It scored 18 wins while conceding no losses, finishing 3.
It was the only undefeated engine. Demolito and Winter also locked up two of the promotion spots smoothly, but the remaining three slots were closely contested. Among the competitors, Igel was the only engine to not lose to Defenchess and Demolito, but it lost to bottom-half engines FabChess and Topple.
Comparatively, iCE was whitewashed by Defenchess and Igel, but it turned in a strong performance against its other rivals, losing only one other game to Winter. Pirarucu went through a tense moment when it lost to Winter in the penultimate round; however, it pulled out a win with Black against Topple to promote. This left the two tied at Minic had the better Sonneborn—Berger scorebut it also had one crash, and the number of crashes was the first tiebreak.
Nonetheless, in a stroke of good fortune for Minic and 8th-placed PeSTOthe League Two engines chess22k and Fritz crashed three times during testing for the division. By TCEC rules, if this happened, the author s would have to update the engine or it is disqualified.
It had been relegated in the previous season because its developer had submitted a drastically different neural network-based version that turned out to be significantly weaker. It defeated seven engines, including fourth-place Vajolet, 2—0. Second-placed Defenchess also turned in a strong performance, finishing with an undefeated For the other promoted engines, Winter and PeSTO performed surprisingly well, comfortably finishing above their peers in 7th and 8th respectively.
I was taking a look at values engines give to pawns and piece and was quite shocked by Stockfish values for middlegame Mg :. So this is way far from the standard "1 piece equals 3 pawns approach", and I was curious about the reason behind it.
I'm aware that this is a small part of Stockfish's or for that case, any serious engine evaluation function, but even so it seems like a really big different from the classic approach.
It is true, that the 1 piece equals 3 pawns approach is pretty accurate, surprisingly so. However as you are probably aware, when evaluating a position, we consider many other aspects as well, such as piece activity, space, king safety, etc.
The difference however is that we don't assign actual numerical values to these other factors. Unlike humans, engines assign numerical values to all factors. The numbers you mention are just a small part of the evaluation function. Check out the middlegame evaluation function for stockfish.
As you can see, just the piece values of all pieces amount to However there are many other functions which add to the evaluation. Most importantly, not all of these extra functions treat pawns and pieces equally.
However note that they can also give a penalty negative value to the total evaluation. In fact for the starting position you have from that function. Stockfish has a much more fine grained evaluation function than we humans do. The pure piece value from stockfish cannot really be compared with the human piece value. In stockfish pieces and pawns can gain points in other ways beyond the values you mention.
Furthermore, stockfish does not consider the piece on its own, but also how it relates to other pieces, e. Mathematically you could also consider it as a kind of approximation or averaging in which you assign a single number human piece value for the very complex system that stockfish uses. There is no reason that the average value human piece value has any relation to one of the parameters ValueMG in the stockfish universe.
I really recommend to see for yourself at the link how much more complete the stockfish evaluation is. Please note that those values are "abstract", later to be modified by the specifics of the position. For example, even though a knight appears 0. It's also worth noting that the "3 pawns equal a piece" is, for all practical purposes, meaningless.
In certain types of positions those with powerful attacks against the king, for instancethe extra pawns can be useless against a piece.
In endgames, three pawns often defeat the piece, specially if not a lot of extra pawns are left. The value of a piece or pawn will depend greatly upon how well it is placed. For various reasons, it may be easier to have the baseline score for a piece represent a piece which is either much worse than typical so that most pieces would have an adjusted score that was higheror perhaps have it represent a piece which is much better than typical so that most pieces would score lower.
As an exaggerated contrived example, consider something like:. Even though White nominally has a substantial material advantage up twice the Exchange, plus three pawnsBlack cannot lose without capturing any of the White pawns or pieces. Although trading a pawn for a rook would normally be a good trade, in this case it is a very bad one since White's pieces are completely useless. Black will nominally be able to trade a pawn for a rook, which would seem like an advantage, but doing so would enormously increase the value of White's pieces.
If it is White to mov Playing with this example, I think White should be able to eke out a draw, and Black certainly should be able to do at least that.
Playing against Stockfish level 3 on lichess. Even in less contrived situations, Stockfish sometimes fails to adequately distinguish between pieces which aren't currently in the fray, but are going to get there, versus pieces which can be very cheaply kept out of the action while the opponent has a substantial majority of the immediately-effective material.More people, like you, are reading and supporting our blog: "Chess Engines Diary".
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Read more. July 01, November 30, Leelenstein is a neural-network engine based on Lc0. It's training also included techniques such as squeeze excitation and learning rate schedulers. Leelenstein also includes non-Zero enhancements to the Lc0 binary, such as a trade penalty and mate scoring. Leelenstein download. July 08, Lichess screen: Houdini 7 by Robert Houdart Currently running a development version of Houdini for testing.
May 28, This version 11 of Stockfish is 50 Elo stronger than the last version, and Elo stronger than the version which famously lost a match to AlphaZero two years ago. This makes Stockfish the strongest chess engine running on your smartphone or normal desktop PC, and we estimate that on a modern four cores CPU, Stockfish 11 could give time odds to the human chess champion having classical time control, and be on par with him. More specific data, including nice cumulative curves for the progression of Stockfish strength over the last seven years, can be found on our progression pageat Stefan Pohl site or at NextChessMove.
In October Stockfish has regained its crown in the TCEC competition, beating in the superfinal of season 16 an evolution of the neural-network engine Leela that had won the previous season. This clash of style between an alpha-beta and an neural-network engine produced spectacular chess as always, with Stockfish emerging victorious this time. Our testing framework Fishtest has also seen its share of improvements to continue propelling Stockfish forward. Along with a lot of small enhancements, Fishtest has switched to new SPRT bounds to increase the chance of catching Elo gainers, along with a new testing book and the use of pentanomial statistics to be more resource-efficient.
If you wish, you too can help our ongoing efforts to keep improving it, just get involved Stockfish is also special in that every chess fan, even if not a programmer, can easily help the team to improve the engine by connecting their PC to Fishtest and let it play some games in the background to test new patches. Thanks Guo! This is also the 10th anniversary version of the Stockfish project, which started exactly ten years ago! I wish to extend a huge thank you to all contributors and authors in our amazing community I would like to thank all the amazing people that made this release possible.
All our testers and our developers, all the people that donate CPU time through fishtest thank you! You are amazing and a special thank to Daylen, our webmaster, and to the people contributing to the final optimized builds:.
SF 9 should improve about 45 ELO in self-play compared to SF 8, but because now we set contempt by default, we could expect something better in rating lists that use games among different engines to measure ELO. Another visible change is the merge of the latest version of Ronald de Man Tablebases code, that is now better at detecting and reporting mate scores instead of TB scores. This is the result of the effort of many people along many months: it has been a huge and hard effort and I would like to thank all the testers for their relentless patience, determination and creativity.Looking Up Too Much Makes You Lose Perspective -- Leela vs Stockfish -- TCEC Superfinal Season 17
I would like to thank Kiran Panditrao for the super fast binaries provided in record time and Daylen Yang for the amazingly fast update of the site: you guys are great! Stockfish 8 is the same version that will go for the TCEC superfinal, it will be exactly the same, so what else should I say? Differences between SF 7 and SF 8: commits, additions, deletions.
Download it here.Stockfish is effectively playing a piece down while holding ground against Leela's break on the kingside.
See PR for details. Fix for overevaluated blocked pawns on the 5th and 6th rank. This is a rewrite of the original idea that uses only two parameters. Thanks to rocky for pointing this out. This sets it by default to false.
Even when enabled, the printing of the info causes no significant overhead. Increase scaling factor for each minor of the opponent side of the queen. Hopefully this helps a little bit for the assessment of positions with queen imbalance, which are one of the well-known Stockfish weaknesses. This fixes an old issue where we want to make a position unique but only change a small number of bits in the key instead of all 64 of them randomly.
This is fragile and can lead to non uniqueness issues in the TT. LTO with static linking is still only working with the latest versions of gcc, causing problems for some devs.
Also tested with clang version 6. Instead of fixing it, remove it, no need to expose an option that will influence time management negatively.Perhaps you have better hardware and engine knowledge to run this position and see if SF ever change its mind from Qf4 to Rxc5?
Just based on a quick look, you are obviously believing that the increased power of the white bishop should make up for the loss of the exchange.
I'm analyzing this on a crappy PC weak cpu, 1 thread. Stockfish 8 still can't find Rxc5 after 49 ply. It prefers 1. However, Stockfish 9 finds 1. Rxc5 at ply It actually finds the same line via two different move orders. The other one is 1. Qh4 Rde8 2. Rxc5 bxc5 3. Next, black responded with Rf8 but what puzzle me is that if I change the number of lines to 9, it will show totally different evaluation, for example, with 9 lines EschInteresting!
Yes, Stockfish is late to get there, dur to its sharp pruning. Actually I use ASMFish Stockfish code complied in asemblywhich obviously prunes Rxc5 initially and analyses it as good for white after manually accepting the move 1. Rxc5 and 1. Qh4 lead to the same position. A good player OTB or correspondence would naturally consider sacrificing the exchange, as the Bb3 becomes a monster. I had the engine Stockfish 6 play against stockfish 9, I accidentally only gave an opening book to Stockfish 6, perfect Stockfish 6 played with the white pieces in the game.
Here Asmfish finds Rxc5 at 14 ply depth and holds it. In this particular position, Asmfish is uber fast, gets to the 35th ply in 5. From my previous tests, it turned out that Asmfish is faster to reach shallow depths up to 22 - 23 and later it gets behind with SF8.
Forums Game Analysis funindsun. Feb 16, 1. Feb 16, 2. Why don't you post a few of the positions 22 moves down the road do we can compare them? Feb 16, 3. Here is what happened in the game Feb 17, 4. Feb 17, 5. Feb 17, 6. Feb 17, 7. Feb 17, 8. Feb 17, 9.
EscherehcsE wrote: funindsun wrote: EschInteresting! Feb 17, Released: Jun 26, Wraps the open-source Stockfish chess engine for easy integration into python. View statistics for this project via Libraries.
Tags chess, stockfish. You should install the stockfish engine in your operating system globally or specify path to binary file in class constructor. If you discover any security related issues, please email zhelyabuzhsky icloud.
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Project description Project details Release history Download files Project description Stockfish Implements an easy-to-use Stockfish class to integrates the Stockfish chess engine with Python.