Chromatix
  • Member for 2 years, 6 months
  • Last seen more than a month ago
  • Helsinki, Finland
4 answers
25 votes
9k views
What is the worst opening move in Chess960 for White?
18 votes

Using @Phonon's Python script, I was able to determine that the worst move is 1. g4?? from the BBQRNNKR starting configuration, or 1. b4?? from its mirror image. This evaluates to -2.5 in one second ...

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2 answers
18 votes
1k views
What is the origin/history of the traditional piece values?
15 votes

In Claude Shannon's paper of 1949, he quotes those values as part of his evaluation function: Most of the maxims and principles of correct play are really assertions about evaluating positions, for ...

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3 answers
7 votes
3k views
Stockfish: What is the maximum (minimum) centipawn score that a position might be evaluated at?
Accepted answer
14 votes

The best way to normalise a centipawn score to [-1,+1] range is using a sigmoid function, as that closely approximates the likelihood of a given centipawn advantage converting to a win, and avoids the ...

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2 answers
6 votes
2k views
How should I play after, or refute, the Tennison Gambit?
14 votes

It looks like your position fell apart pretty early on, a symptom of poor opening theory. Your King and Queen were exposed to attack within the first few moves, and White ruthlessly exploited that ...

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9 answers
23 votes
15k views
Is rotating a pawn so that it faces a different direction and then moves in that direction technically permitted according to the 2018 FIDE Laws?
11 votes

The official PDF of the FIDE Laws of Chess includes illustrations of the legal moves for each piece. These clearly show the white pawn moving "up" the file (including the two-square move from the ...

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2 answers
16 votes
2k views
Can an Irwin Cheat Detector catch a user who is using a Leela chess bot for cheating?
Accepted answer
11 votes

Leela works by performing an exceptionally sophisticated positional evaluation at a relatively shallow search depth, whereas most chess engines work by performing a simple evaluation at as deep a ...

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7 answers
13 votes
3k views
Arrange 5 non-attacking knights on a 5x5 toroidal board
7 votes

There are essentially six solutions that are rotationally and translationally unique. Two of them yield five translations and five more rotated translations each, for a total of twenty: NNNNN ..... ....

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3 answers
5 votes
562 views
Is there an online database for the endgame KRPPKRP?
6 votes

All of the Syzygy tablebases are available here: https://syzygy-tables.info/ These cover all endgames up to 7-man, and provide WDL (win-draw-loss) and DTZ (distance to zeroing move) data. Syzygy ...

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8 answers
15 votes
18k views
What is an accurate way to evaluate chess positions?
5 votes

Surprisingly, it turns out that a Minimax engine will play reasonably well when the evaluation function is random; this is known as the Beale effect, and results from the principle that positions ...

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6 answers
17 votes
915 views
Why isn't chess played with flat pieces?
5 votes

Flat chess pieces do exist on the market, in the form of "pocket chess" sets in which there isn't room to provide 3D pieces. In this example, notice the lack of extra queens for promoting pawns to: ...

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2 answers
0 votes
1k views
Long algebraic notation-piece promotion
4 votes

Most games published for human study are written in short algebraic notation. For each move, the destination square is always specified, the moving piece is specified unless it's a pawn (in which ...

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2 answers
5 votes
1k views
Stockfish 10 working on only 1 core at a time
4 votes

Those appear to be options to set in your Web browser, which is effectively the platform that LiChess runs on. You don't mention which browser you're using… Chrome uses multiple cores and thereby ...

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5 answers
7 votes
4k views
What can I learn from my "80 average centipawn loss" game, which I thought I played well?
4 votes

If you aren't a very strong player - by which I mean Master level - then Stockfish is regularly going to find significantly better moves than you do, simply because it can look further ahead in the ...

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2 answers
7 votes
717 views
How do they determine the starting position for Fisher Random / Chess 960?
4 votes

Many professional-grade chess clocks are capable of randomly choosing a valid Chess960 starting position and describing it to the players. I suspect that in many tournaments, this is how it's done. ...

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3 answers
6 votes
236 views
How do generic game engines work?
4 votes

I don't know about Zillions specifically, but it's a reasonably good strategy in most games to maximise your own flexibility of action while minimising your opponent's. This is certainly true for ...

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1 answers
3 votes
127 views
ChessBase Nalimov tablebases
3 votes

Apparently Fritz 14 is capable of reading the newer Syzygy format tablebases. Certainly the latest Fritz can. These tend to take up less space than Nalimov format, which used a simpler compression ...

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1 answers
2 votes
151 views
Can engines use the current pawn structure to refine its search/eval?
3 votes

Something very similar is doubtless encoded into AlphaZero and Leela's neural network evaluators, which are very positional. Most conventional Minimax engines, by contrast, are stronger at tactics ...

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1 answers
2 votes
68 views
What do the numbers mean at the end of predicted variation opcode in and EPD entry?
Accepted answer
2 votes

On a strict reading of the EPD spec, the example shown is malformed; the pv opcode should only contain a list of moves, not any commentary on it, which should be moved to other opcodes. Indeed the ...

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2 answers
5 votes
886 views
Why didn't Donald Byrne capture with the queen instead of pawn (against 13-year-old Bobby Fischer in the Game of the Century)?
2 votes

In general, it's preferable to recapture with the weakest piece available. If nothing else, this means that you lose the least material in the event of a sequence of recaptures on the same square. ...

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2 answers
2 votes
292 views
How many moves can be expressed with algebraic chess notation?
Accepted answer
2 votes

I immediately notice that you've missed the castling moves (O-O and O-O-O). I would list the pawn-promoting moves according to their PGN syntax (=Q/R/N/B suffix), as that's the most commonly used in ...

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4 answers
4 votes
302 views
Chess software that enables you to set up a position from scratch?
1 votes

Most general-purpose chess software has this feature, usually under "Edit Board" or similar menu entries. On Linux, usually there are two components to the software which are developed independently -...

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1 answers
-1 votes
174 views
What are the maximum number of pieces that can be checking a king at once
1 votes

If you have an unlimited number of pieces to place, and ignore the mechanics needed to get them there in actual gameplay, it's easy to show you can surround a king with eight queens and eight knights ...

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2 answers
3 votes
245 views
An objective measure of the difference in strength between top programs and top human players in the four most popular forms of chess?
1 votes

While it is possible to write engines that can play different chess-family games, doing so generally yields an engine that are only "competent" at each one, at best. The best engines for each ...

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2 answers
5 votes
736 views
Why is Fritz 16 Grandmaster Playing Weak Endgames?
0 votes

Most engines are weak in certain types of endgame, unless they are provided with an endgame tablebase (EGTB) or sufficient search depth to reliably find the way to the best mate, draw or conversion. ...

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