# Question
Title: Mate-in-N problems where N scales indefinitely with board size
## Motivation - *Long range* mating patterns

This question is inspired by my recent interest in infinite chess and the post on MathOverflow Checkmate in ω moves?. Since my chess endgame skills are quite lacking, I am sincerely asking the chess community for help and inspiration. My ultimate goal is to find and collect various kinds of positions with a limited amount of pieces on an infinite chess board that are winning for white but where checkmate can take an arbitrarily long time (We omit the 50-move-rule). I apologize if this question is too vague / open-ended.

There are well-understood positions on chess boards with n×n squares (i.e. we extend the "small" 8×8 board) where the position is winning for white, but the number of moves to checkmate is increasing in n. Let's look at some of them.

## Known examples

Consider this example rook vs bishop endgame that we have set up on the bottom left corner of this **n×n** chess board: (I will paraphrase an explanation by user Noam in the answer to the above-mentioned post.)

White's winning plan is to play something like Rb7, Ra7, and then a waiting move like Ra6 to force Black to play Ka1 when Rxa3 is mate (zugzwang). On the 8×8 board Black can postpone this for only a few moves. For example, if 1...Bd6 then 2.Rb6 and if Black saves the Bishop, then 3.Ra6(+) etc. (best is 2...Ka3 but we know that after capturing the bishop white wins in just a couple of moves on any board size). Black does better with 1...Be7, so after 2.Rb7 Black can play 2...Bc5 to prevent Ra7; but White continues with 3.Rb5 and next move either takes the Bishop or initiates the mating pattern with Ra5. Note that if White went to a "random" spot on the second file Black would escape with Ka3; that's why it's important to move to the row the Bishop is on and threaten it.

On an n×n board the same position is checkmate in around **log₂(n) moves**, which seems to be the maximum for K+R against K+B. For example, with at least 9 columns and 11 rows, Black could hold on to his Bishop for an extra move by starting 1...Bi11, so that 2.Rb11 can be answered with 2...Be7 holding a11. But then 3.Rb7 reduces to a previously solved problem and white wins as before. To survive one more move than that, Black would have to start by moving the Bishop 16 squares out, to survive two more moves Black would have to move it 32 squares out etc.; in general if Black moves to file n+1 then White checkmates in around log₂(n) moves.

By making the board arbitrarily large the checkmate can be drawn out arbitrarily. However, note that even on a truly infinite chess board with no north and eastern edges, white always wins in some finite amount of moves because black has to commit to a distance with his first bishop move, i.e. he has to make *some* move. Thus, this is called "checkmate-in-ω" because black can choose any arbitrarily large number of moves to postpone the checkmate.

Three other examples of checkmate-in-ω are pictured here: (I know that the last 2 positions are artificial.)

In all cases, black can postpone the checkmate as long as he wants by moving the rook besides his king as many squares away as he wishes. In the first position of the queen vs rook endgame, White wins after around **log₂(n) moves** again by repeated checks and an eventual fork - note that the board edges play an indispensable role for the checkmate. In the second position, white wins after chasing the Black king north with his queen and rook for **n moves** (alternatingly moving his rook and queen up). Here the board edges play no role in the checkmate pattern and I omitted them. In the last position, white will win after moving 3 pawns, after which the bottled-up queens escape and finish black off. After each pawn move, black gets to move his rook arbitrarily far along the second row, threatening mate; white will have to move his king for **n moves** one step at a time, pursued by black's, until reaching the rook to get a "tempo" for the next pawn move. (Thus, this position is technically even checkmate-in-ω\*3 on an infinite board, since black can move his rook away arbitrarily far away 3 times.) Here, the lower board edge is indispensable for the checkmate threat by black.

(Nota bene: There are some extensions of these positions with additional pieces / pawns so that black can choose not only once but several times how many moves are still needed for white. An example for such an ω\*2 position, which is an extension of my first example, can be found here. This is welcome, but it is not necessarily the kind of novel mating ideas that I am looking for.)

## My Question

Do you know of other examples of (maybe even classic) chess endgame positions with a fixed amount of pieces that can get drawn out arbitrarily long only by extending the board from 8×8 to n×n (and keeping all else constant)? Is there maybe some systematic way of constructing these positions with long-ranged mating nets? Some Q-R and R-B endgames have this feature as I showed in this post; maybe we can also find this feature in various other endgames? (where maybe bishops and knights also play a more important role?) I would like to collect as many examples of such mating nets as possible and, ideally, be able to combine various ideas in the same position, in the end. I am interested both in cases where the board edges play a role and in edgeless boards. I am not so much interested in slight modifications of these positions but in different mating ideas like these and endgames with similar features.

# Answer
> 4 votes
A simple example should come from knight-bishop endgames, assuming n is even. All pieces start out close to one corner of the board and the lone king needs to be chased into a corner of the opposite colour. The farther away this corner is the longer this will take.

---
Tags: endgame, problems, checkmate, chess-variants, mathematics
---


# Question
Title: Why exchange bishop for knight in this endgame?
In this position, Stockfish gives black (me) -8.1 and recommends BxN.

```
8/5p2/4pkpp/p1n5/Pp6/1Bb1PP2/2PNK2P/8 b - - 7 28

```

Instead I played Kf5 and the evaluation plummets to -2.1.

My understanding was that generally bishops are preferred over knights in endgames, so I'm trying to understand what is different about this position. Looking at Stockfish's line, it looks like somehow this is useful for dragging the king away from protecting the pawn on H2, which Black's king then goes after.

Is there a useful principle to learn from this?

# Answer
Easy. Exchange BOTH pairs of light officers (BxN, then NxB) and you have an almost trivial won pure king/pawn endgame. General Principle: If you are material up in the endgame, exchange officers. If down, pawns. (As usual, exceptions abound.)
> 12 votes

# Answer
After Kf5 white replies with Nc4 and the only way to avoid losing the a pawn is to play the knight back to the poor square b7 and it is very difficult to see how black can make progress. If the knights are ever exchanged then the position becomes a trivially drawn opposite coloured bishop endgame.

```
[fen "8/5p2/4pkpp/p1n5/Pp6/1Bb1PP2/2PNK2P/8 b - - 0 1"]

1...Kf5 2. Nc4 Nb7

```

On the other hand, if black exchanges off the bishop for the knight by Bxd2 then black is left with a good knight versus a bad bishop with a potential distant passed pawn on the king side. (Note that if the white bishop moves then that immediately loses the a pawn.) Black will play moves like g5, Ke5, f5, g4.

Endgames are all about calculation and so black should also calculate carefully what happens if the other minor piece is also exchanged by Nxb3. This opens up the route for white to play a sequence of moves like Kd3-c4-b5, Kxa5 and queen the a pawn. Can white win via this route? The answer is not quite. With correct play black queens the h pawn one move before white can queen the a pawn and as they are on the same diagonal black's queen covers a8.

```
[fen "8/5p2/4pkpp/p1n5/Pp6/1Bb1PP2/2PNK2P/8 b - - 0 1"]

1...Bxd2 2. Kxd2 Nxb3 3. cxb3 Ke5 4. Kd3 f5 5. Kc4 g5 6. Kb5 g4 7. fxg4 fxg4 8. Kxa5 h5 9. Kxb4 h4 10. a5 g3 11. hxg3 h3! (11...hxg3? {only draws}) 12. a6 h2 13. a7 h1=Q

```

> Is there a useful principle to learn from this?

Calculation is key in endgames. If you watch the top players they don't rush in and play the obvious move when they think they have a winning endgame. They take the time to calculate the position through to the win and only then play the move.
> 12 votes

# Answer
If the engine goes -8.1, it found a clear win, so subtle strategic considerations are not relevant anymore for the engine. But for the human, they may be.

The pawn endgame is less clear, far from trivial. Pawn endgames can be extremely complex and I would not transition unless I am 100% sure that it is winning. Transitioning here is an unnecessary gamble. In this position I believe you maintain some serious advantages if you go Bxd2 and then keep your knight on c5.

The knight on c5 is cutting the king off, is preventing c3 or c4, and is threatening to capture on a4 anytime the bishop moves. With that in mind, black can increase the pressure by going for the h-pawn with his king. If white choses to guard h2, then he ends up in a totally passive position where he cant move his king or bishop, and will soon run out of moves. So basically, white will have to let go of another pawn, sooner rather than later.

If there is one lesson to be learned from this position i believe its this:

Don't just follow strategic dogmas, but examine if they really apply.
> 2 votes

---
Tags: endgame, strategy, knights, bishops
---


# Question
Title: What is the earliest known appearance "Fool's Mate"?
A quaint question I had lately: what is the earliest known appearance of the “Fool’s Mate”? I refer to both the name and the move sequence.

A quick search with Google Books revealed a reference dated to 1672 in *The famous game of chesse-play* by Arthur Saul and John Barbier.

Here is an image of the relevant text portion.

Transcript:

> *Of a Mate to bee given at two Draughts.*
>
> **CHAP. XX.**
>
> Meeting with an eaſie Gameſter, thou mightſt likewiſe give him a Mate at two draughts, if he ſhould chance to play thus: Firſt, to remove his Kings Biſhops Pawne, a ſingle draught (which I told thee before, was ill to play for the firſt draught) thou thy Kings Pawne, a ſingle remove: he for his ſecond draught, his Kings knights pawn, advanced a double remove: thou bringing forth thy Queene, into the Fifth Houſe of thy Kings Rooks file, giveſt him Mate at thy ſecond draught: which Mate for him that hath it given him, may well (if the ſchollers Mate, be cal’d the peſants Mate) be termed the fools Mate.

# Answer
In reference @Rewan Demontay's answer, I know that Augustus, Duke of Brunswick published *Das Schach- oder Königsspiel* under the pseudonym Gustavus Selenus in 1616. I can't confirm that this work actually mentions Fool's Mate (I don't speak German, and I can't find the full text in online references) or that there is no earlier reference.
> 2 votes

# Answer
By a stroke of luck, Tim Krabbe mentioned an earlier occurrence on his site. It is in his AD Magazine issue #135 entitled "LOYDS MOOISTE VERGISSING,", meaning "LOYDS MOST BEAUTIFUL MISTAKE."

In Dutch: "Wit en Zwart helpen elkaar daarin om tot een mat te komen, zoals in het snelst mogelijke mat vanuit de beginstelling, het Narrenmat (1.f3 e5 2.g4 Dh4 mat). Al in 1616 noemde Gustavus Selenus dit mat, dat in een normale partij nauwelijks kan voorkomen."

In English, this means " White and Black help each other to arrive at a mate, as in the fastest possible mate from the starting position, the Jester mat ( 1.f3 e5 2.g4 Dh4 mate). Gustavus Selenus called this mat as early as 1616, which can hardly occur in a normal game."

Now we have a reference to 1616 and the name Gustavus Selenus, although I am unable to trace it.

**Addendum 11/8/2021:** In an earlier comment, @Hauke Reddmann issued a Google Books link to "Schachkompositionen: Die besten Aufgaben und Komponisten der Schachgeschichte. Mit über 500 Rätseln und Lösungen". On page 25 information is given that makes the book an additional source.
> 4 votes

# Answer
The names and the moves of both Fool's Mate and Scholar's Mate appear in Francis Beale, *The Royall Game of Chesse-Play* (1656). Aside from these two, the book contains games of Greco from a manuscript now lost.
> 2 votes

# Answer
Not an answer, but too long for a comment:

Bingo! Just found the reference in Werner Lauterbach "Faszinierendes Unsterbliches Spiel": It's related to the Arthur cycle, named "Auf der Suche nach der Fee Floribelle", has a chess-related plot, and googling that I found this: German link. This explicitely mentions the Shepherds mate (Schäfermatt). (Note this is not the Fools Mate, but 4.Qxf7!)

But, but, but: (I spare you the details) This note also claims most probably the "medieval source" is a fake and Wieland, who "reported" it, did a great imitation himself, thus locating the work ~1800.

Sorry my super-memory mislead you.
> 1 votes

---
Tags: history, books, fools-mate
---


# Question
Title: What is the highest number of pieces from one side that can be involved in a checkmate?
What is the highest number of pieces from one side that can be involved in a checkmate? "Involved in a checkmate" is defined below.

A non-king piece is involved in a checkmate 'if removing it from the checkmate position would change the position to one which is either not checkmate or is illegal'. The king is involved in a checkmate if it is the only piece of the checkmating side that attacks one of the other king's escape squares.

# Answer
> 9 votes
My original thought was that the limit was nine pieces; one for each of the 8 squares around the king, plus one for the mating check on the king's square.

```
[FEN "8/2K5/8/3Pk3/2P2PPB/3P2P1/2N5/8 b - - 0 1"]
[startflipped ""]

```

But, as someone pointed out in a comment, pieces can become "necessary" even if they aren't controlling one of those squares. If the Black pieces don't have to be "necessary", then we can have a board where **all** White pieces are "necessary" for below to be a legal checkmate position.

Although, seven of them are just preventing check. The rest do the actual job of checkmate.

```
[FEN "3b1q1q/1N2PRQ1/rR3KBr/B4PP1/2Pk1r1b/1P2P1N1/2P2P2/8 b - - 0 1"]
[startflipped ""]

```

# Answer
> 16 votes
Here is a solution with all 16 white pieces, all mandatory for checkmate, without promoted units and without needing to protect the white king from checks. If you remove any white piece but the king, the position is still legal but not a checkmate anymore. Moving the wK to a random square (say, h1) would also destroy the mate.

```
QNr1R1b1/P1BpnP2/3P4/qP4Pr/Rn2kP2/1N4PB/2P2K2/8 w - - 0 1

```

Last move is Nc6-b8# or d5-d6#.

# Answer
> 1 votes
Here's another way to involve all 16 White units. This time the check is orthogonal.

```
[Title "All 16 White units in the mating-net"]
[fen "r2N1R2/1p2pn2/PBB1P3/Q4kPP/8/5nPK/PNPP1R2/q1r1b3 w - - 0 1"]
[StartFlipped "0"]

1.

```

wNd8 stops Ke6; wPg5, Kf6; wPh5, Kg6; wBc6, Ke4; wPg3, Kf4; wK, Kg4; wRf8, N7e5; wPa6, Rxa5; wBb6, b5; wPe6, e5; wPa2, Qxa5; wNb2, Qe5; wPc2, Rc5; wPd2, Bxa5; wRf2, N3e5.

Legality: Perhaps wPa6 did bxPa and wPg5 did fxPg. (Or perhaps one of them captured \[bBc8\].)

# Answer
> 0 votes
Here is another 16-piece set, in which I strived for economy. I chipped down to **5 Black pieces**; three less than @Evargalo, for whom I must thank for their matrix. I've also incorporated a new reason for needing a piece.

```
[FEN "QB1rR3/P1NPnN2/1P6/1rP5/4k3/1PP3PB/qRKP4/8 w - - 0 1"]

```

Here is a list regarding why each piece is needed.

* wKc2: Guards d3.
* wQa8: No checkmate.
* wRb2: Without it, the position is illegal.
* wRe8: Pins bNe7.
* wBb8: Prevents bRxa8.
* wBh3: Guards f6.
* **wNc7**: Without it, the wQ's check is impossible, and thus the position is illegal. It is impossible for c6xd7+ to have been the last move, as that would require one too many captures.
* wNf7: Guards e5.
* wPa7: Prevents bQxa8.
* wPb3: Prevents bQd5.
* wPb6: Prevents bRb7.
* wPc3: Guards d4.
* wPc5: Prevents bRd5.
* wPd2: Guards e3.
* wPe7: Prevents bRd5.
* wPf3: Guards f4.

---
Tags: problems, checkmate, records
---


# Question
Title: I can play the London system exclusively up to what rating?
There are many GMs who sometimes play the London system, but none of them play it exclusively. By "exclusively" I mean play it in over 99% of my games when I'm White, I mean adopting the London system not as a secondary weapon but as my only weapon. So if I continue to learn and improve and become stronger over time, at what rating will I need to stop playing the London system exclusively?

Note that with Black I ALSO play the London system exclusively, I play the Slav and the Caro-Kann.

# Answer
Problem with London is not that it gets bad at certain rating - problem is that it's very monotonous opening, so you don't get to experience many structures (variety is crucial for improvement).

What can happen is that you will progress very quickly to 1800/1900 fide or something like this and then tilt due to this. At least according to IM Andras.

Note also that Slav and Caro-Kann are not really similiar to London except in most superficial aspects. It's true that in all of these you play c6+d5+Bf5 (and even this depends on particular line, just look at exchange Caro-Kann), but tactically and strategically they are totally different beasts.

Chess is complex game. The trick to getting good at it it's embracing this complexity in all of its various forms, not trying to make it simple. So the answer is that you probably won't reach a rating at which London is not good enough (because it is always good enough), you just won't improve as fast as possible at some point.
> 15 votes

# Answer
Matija Sirk's answer is very good and it's true that learning different sorts of positions will improve your overall chess skill. If your goal is to be the best chess player you can possibly be, and if you are young and talented enough that that may be very good, then I say you should definitely play lots of different openings.

BUT ...

"Chess is a lake in which a mosquito can bathe and an elephant can drown" (Indian saying).

Suppose you are more like the mosquito?

Suppose that, in addition to chess, you have a job, a spouse, some kids, maybe even (gasp!) some other hobbies! Maybe you want a good portion of your total time playing chess to be actually *playing* chess, rather than studying?

In that case, you can play the London exclusively, forever.

Even at the highest level, it is only recently that players play all sorts of openings. Bobby Fischer had a relatively limited opening repertoire. Lev Alburt, who was a GM (if not quite at Fischer's level) played the Alekhine's defense as Black pretty much all the time.

I think that, unless you are going to try to make chess your career, your goal should be to get as much enjoyment as possible out of the game. If the London makes you happy, go for it.
> 2 votes

---
Tags: opening, rating, london-system, repertoire
---


# Question
Title: Tools for helping to learn openings by heart
Is there any tool that can help us learn openings by heart? I tried to use Fritz but without success.

# Answer
> 7 votes
Two well-known programs that are meant specifically to aid in the memorization of opening variations are

1. Chess Position Trainer
2. Chess Openings Wizard (formerly *Bookup*)

Both programs are designed to recognize and handle transpositions seamlessly, and they allow a player to drill all the positions that are part of any repertoires that he or she inputs.

# Answer
> 1 votes
Chessable is famous for learning chess openings by the MoveTrainer space repetition. Check out MoveTrainer at https://www.chessable.com/movetrainer.

# Answer
> 0 votes
Personally I use Chessable. It makes you play through all the variations when you review a course, and there are a bunch of free courses on there that are excellent for getting started with an opening.

The Short & Sweet series is pretty good. Sam Shankland, Anish Giri, and a bunch of other masters have some good S&S courses that are 20-30 lines or so, as they are just a demo version of the massive "Lifetime Repertoires" series. They're great for club players.

There are also free courses published by community members that are more extensive. I used the "Ruy Lopez: Masterclass Edition" course to learn a new opening that I now enjoy immensely.

If those aren't enough for you, you can find some pretty low-priced courses on more or less anything you want. Lifetime Repertoires courses are expensive and have huge numbers of lines, but there are smaller ones you can get for a lower price. For example, I am an owner of "Rafael Leitao's Najdorf Sicilian" which was around $5 and has 150 lines or so.

---
Tags: opening, learning
---


# Question
Title: The king had a place to move, how is this checkmate?
The king had a place to move, how is this checkmate?

# Answer
**TL;DR:** This is checkmate because White cannot (1) move the King out of check, (2) block the check, or (3) capture the piece giving check.

**1. Move out of Check:**
The White King cannot move to the c1, d2, or e2-squares as those squares are occupied by White's own pieces (the dark-squared Bishop, the d-pawn, and the Queen, respectively).

This leaves the c2-square and e1-square as the only potential escapes. The White King cannot move to c2 because of Black's Queen on b3, and the Black Knight prevents escaping to e1.

**2. Block the Check:**
White has no piece that can legally move to c2 to block the check.

**3. Capture the Piece giving Check:**
White has no legal move to capture the Black Queen on b3.

```
[Title "Checkmate"]
[FEN "r1b1kb1r/ppp2ppp/5n2/3p4/4p3/PqPnP1PP/RP1PQPB1/1NBK2NR w - - 0 1"]

```
> 3 votes

---
Tags: checkmate
---


# Question
Title: How to determine the right plan in a Carlsbad structure on the queenside for examples similar to this one
Let's say that I'm play from the Black side this position:

```
[FEN ""]
1. e4 c6 2. d4 d5 3. exd5 cxd5 4. f4 Nf6 5. Nf3 Bg4 6. h3 Bxf3 7. Qxf3 e6 8. c3 Nc6 9. Bd3 Be7 10. Be3 a6 11. Nd2 b5 12. a3 Rb8 13. O-O

```

My question is: How do you know when to play Na5 and when to play a5 continuing with the minority attack in such Carlsbad structures? I'm asking in general, not just for this position. And I would be happy if you have a reference like a book where you read about the strategy of playing this.

# Answer
> 2 votes
The plan defusing the minority attack is know since ages: b4, Nb3 (or d3), Nc5. The attacker only remains with a weak pawn on b5 and White's c3 is totally safe. (Your example has reversed colors to the "usual", I reversed everything too)

So if it should succeed nevertheless, some none-excluding possibilities are...

* Black's d-pawn is still on d6. Only after a5,b4 etc. has been done, it moves to d5.
* All knights of White have been exchanged.
* Pressure on c3. b4 simply hangs the pawn.
* None of the above, but b5 is safe (e.g. White can only pester it with a B but the K protects it), Black just ignores the Nc5 and invades on the a file.
* Specific to your example, Black must first do prophylactic measurements against f5, which is the "mirrored" minority attack for White.

Random resource google

---
Tags: strategy, pawn-structure
---


title: How to become a chess photographer?

text:
# Question
Title: How to become a chess photographer?
I have a keen interest in both chess and photography. I absolutely adore the works of David Llada, Lennert Ootes and their kin. My question is, if one wants to become a chess photographer, what is the path he/she needs to choose?

In my particular case, I must point out that I am not even a professional photographer with any degrees. Do I have a chance to make a career in chess photography?

# Answer
> 3 votes
All I can say is, the people in this forum are chess players, not photographers. However, a job is listed at the World Chess Hall of Fame for the Saint Louis Chess Club demanding you "execute photography and design projects as needed (wow!): https://worldchesshof.org/about/open-positions

However, if you're really looking to pursue photography, specifically sports photography, specifically chess photography, you are better off asking a group of photographers, or even someone like the popular content creator Eric Rosen who is an official FIDE Photographer as well as an IM, so he probably knows what you would be getting into. I suggest talking to him via the Ask me Anything channel in his Discord server, though a response is not guaranteed.

# Answer
> 1 votes
Being a good chess photographer has nothing to do with being a good chess player and everything to do with being a good photographer. Concentrate on that.

> I am not even a professional photographer with any degrees

There is a fixation nowadays with getting a degree. This despite the fact that most universities seem to have become offshoots of Andrex University.

If you want to become good at any practical subject like photography the best way is something like an apprenticeship. As I strongly suspect that apprenticeships in photography don't exist your next best bet is to try and get work, even if it is very badly paid, as some kind of photographer's assistant which will give you the chance to learn what matters from a professional.

> Do I have a chance to make a career in chess photography?

How long is a piece of string? What your chances are will depend mostly on you, on how hard you are prepared to work at it and whether you have any talent for photography. It will also depend on luck, on whether you meet the right people who can help you become a good photographer. You are far more likely to find those people in a photography forum than a chess forum.

---
Tags: careers
---


# Question
Title: How many games would Magnus Carlsen need to win to get an ELO of 3000?
For the purposes of this question, assume that he wins every game. Go according to his current schedule. Assume the opponents keep their current rating. If you run out of schedule, assume the rating of Carlsen's average opponent.

# Answer
> 7 votes
The answer is that it depends heavily on his future opponents and schedule. Instead, lets first answer an easier problem. If we assume his opponents' average ELO of say 2770 (the current average of the #2-#10 players in the world), how good does Magnus need to score against them to achieve and maintain an ELO of 3000?

Based on ELO calculations, he would need 10^(3000-2770)/400 ~ 3.758 wins for each loss, ie an average score (counting wins as 1, draws as .5, losses as 0) of .7898.

Alternatively, we can use the ELO formulas to calculate (with the help of Excel) Magnus would require 52 consecutive wins (no losses, no draws, just wins) against 2770 opponents to raise his ELO from 2852.6 to 3000

For context, the longest win streak in high level chess was Bobby Fischer's 20 straight in 1970.

# Answer
> 1 votes
A player's FIDE rating is updated according to the formula

`Rnew = Rold + K(W-We)` where

```
K  = 10, according to (https://www.fide.com/docs/regulations/FIDE%20Rating%20Regulations%202022.pdf).
W  = actual score.
We = expected score.

```

Expected score is calculated using table `8.1b Table of conversion of difference in rating, D, into scoring probability PD, for the higher, H, and the lower, L, rated player respectively`.

Let,

```
Own rating Carlsen    2853
Opp rating            2770
Rating difference       83
Expected score per game  0.61, according to FIDE table.
Rating update per game   3.9 <- 10 * (1 - .61)

```

To achieve a rating improvement of 3000 - 2853 = 147 Carlsen needs 147 / 3.9 = 38 consecutive wins.

Take a player with rating 3000. To maintain this rating, the player must score 79% against an average opponent rating of 2770. Or 70% against Carlsen himself.

---
Tags: rating, elo, master-games, carlsen, super-grandmaster
---


# Question
Title: How do we exactly establish if a position/center is "open" or "closed"?
The question is closely related to this one, but not exactly the same, since in that question the topic is addressed perhaps more from a computer science point of view.

During my chess studies I always wondered how to be sure to classify a position as closed or open in order to make my choices and create my plans, e.g.: I know I may start and attack on my opponent's king castled kingside if the position is closed, but I'm unsure if the position yet is closed AND it wil stay close (i.e.: could the center be opened soon?...)

Some insights on how to evaluate the "openness" of the position are given in the question I linked before, but could you help me to find a "way of thinking" to be used during a game to establish if the position is open/closed and if it will still be the same in the future?

# Answer
I think you are looking at this a bit backwards. You're asking whether or not the position is likely to remain open or closed and want to use that to direct your plans. The game is yours to make. You should instead be looking at your position (and your own strengths as a player) and let that guide you on whether an open or closed position would be in your favor. If it doesn't seem feasible for you to exploit the benefits of an open position, try to keep it closed. If it doesn't seem feasible to exploit the benefits of a closed position, open it up.

I think people oftentimes think about open/closed positions as a way to determine whether or not certain actions are advisable (e.g. trading a knight or attacking a king). But you could also look at it the other way. Look at the ways the strategies differ for open and closed positions and judge which one is more feasible to work with based on what you have going so far. Once you know that, figure out what you need to do to reach an open or closed position. Then, once you've achieved that goal, work on exploiting the strengths that led you to pursue this position.

The key thing to remember is that the game isn't something that just happens. You are making choices on what to do. It's not so much a question of whether or not the position will be open or closed, it's a question of which position should you be working towards.

---

However, that is more towards your question about "if it will still be \[open or closed\] in the future?" For that, you should decide which is preferable and try to find strategies to move the game to whichever state you want.

As for how to determine if a position is open or closed, it all comes down to the pawns. If several pawns have been exchanged and there are few pawns in the center, it is open. If most of the pawns are still present on the board, and the center pawns in particular are blocked and not able to be exchanged, it is closed. You can open up a position by exchanging pawns, and you can close a position by blocking pawns.
> 2 votes

# Answer
In the old days, I remember reading that open games were those that started 1. e4 e5 (actually, P-K4, P-K5, this was a while ago!) Semiopen were 1. e4 anything else and closed were ones that started with a move other than 1. e4.

More recently, a lot of people (e.g. Gotham Chess) talk about the sheer number of pawns. The more pawns, the more closed. That's a much better guide. Maybe it's as good as you can do with a simple rule.

Really, though, it's about how easily the pieces can move around. That depends not only on how many pawns are on the board, but how they are configured, and also on which pieces are still on the board and where they are placed.

In particular, a "bad" bishop could be pretty good, if it is outside the pawn chain. There was a great example of this in one of Yasser's courses, but I forget which course.
> 1 votes

# Answer
Well, we really don't. We can use some heuristics like:

* The number of pawns currently in the center.
* Whether those pawns are attacking or blocking each other.
* How easy/convenient it would be for either side to push their pawns forward.

But we can't really find objective criteria that classify positions into open or closed and expect that to tell us anything useful about how to play. The plan to choose in a specific position can change completely due to tiny specific details.
> 1 votes

---
Tags: evaluation, closed-position
---


# Question
Title: What sets the absolute value of players' Elo rating?
I understand that the way the Elo updating process works, if player A has a 66% chance of beating player B, then A's Elo rating will converge to be 100 higher than B, and so forth for 74%, ... etc. **Assume for the purposes of this question that the assumptions of the Elo rating system actually hold (e.g. if A has a 66% chance of beating B, and B has 66% chance of beating C, then A always has a 74% chance of beating C)**. However, this description is consistent with player and ELO of B having Elo of 10 million, and player A having an Elo of 10 million + 100.

EDIT: So there is an arbitrary "scaling" in the ELO rating: In a world with only two players, scores (1000, 1100) are equivalent in interpretation to (2000,2100). How does the algorithm that is used in the chess world end up setting this absolute scale?

* E.g. does it always try to make sure that the mean score is 1500, by adjusting everyone's score uniformly when the mean deviates? If so, who is included in the mean? (everyone who went to tournaments?)
* Or does it simply always assign a particular initial score?

(Note, this question looks similar, but doesn't actually answer my question).

# Answer
> 6 votes
There literally is no "absolute value" for Elo ratings, if I understand what you mean by that. A single player's Elo rating, in isolation, means nothing. The only thing the Elo rating scale is good for is comparing two (or more) players; the only thing that matters is the difference between the players' ratings. Two players' ratings could be 1500 and 1600, or 10,000,000 and 10,000,100 - the interpretation of the ratings is exactly the same either way. You mentioned that the Elo rating system was designed so that an average club player would have a rating of 1500 (I've actually never seen it described that way before - what I had previously seen was that it was designed so that a player who was capable of scoring 50% in the US Open would have a rating of 2000). But that is arbitrary; any number could have been picked.

The situation you describe where the billion terrible players come into the rating system, dump a bunch of points, and then leave, is an age-old issue that's called "ratings inflation" - this is not unusual, and in the aftermath of "The Queen's Gambit", I'm wondering if we're about due for a new period of ratings inflation very soon... There's an analogous "ratings deflation" scenario that happens when a bunch of players come into the system with low ratings, play very well, take a bunch of points from established players, and then leave the system. This happens in areas with strong scholastic chess programs, where it often happens that kids come into the system at low ratings, their level of ability increases much faster than the ability of the rating system to keep up with it, and then they leave the player population after they leave the scholastic chess program. So they have taken away rating points from established players, who have no hope of getting them back from those player, because those players have left the player population. There are a number of approaches one can take to combat this problem, probably the simplest (and the one I heard of the most in the early days of the Elo rating system in the USCF) was simply doing periodic manual adjustments to players' ratings to push them back into line to where you want the average rating to be - for example, something like declaring, "On date X, all players ratings will be manually increased (or decreased) by N points, across the board".

This is assuming you actually see ratings inflation / deflation as a "problem" of course, since as stated, the actual number is arbitrary. And it's really not a "problem" if you have no expectations of the rating system other than it being valid at some specific moment in time. The place you run into "problems" is trying to use ratings to compare players across large gaps of time - like, "Could Bob Smith, who was rated 2100 in the year 1989, have beaten Bill Jones, who is rated 2000 in the year 2021?" Ratings inflation / deflation completely messes up trying to use players ratings to discuss questions like that.

# Answer
> 2 votes
> What sets the absolute value of players' ELO rating?

The design of the rating scale is explained by Elo in Chess Life, august 1967 (P243).

> In the chess world, the player category or class concept has been used extensively, altho quantitatively undefined. The original USCF scale arbitrarily set the player category at 200 rating points. By definition, this interval now measures the "standard deviation" of individual performances in single games.
>
> ```
> With the class interval defined at 200 points, the USCF categories are
> then designated as fo11ows:
> Over 2400 Senior
> 2200 2399 Master
> 2000 2199 Expert
> 1800 1999 Class A Player
> 1600 1799 Class B Player
> 1400 1599 Class C Player
> etc,
>
> ```

While the rating scale is set arbitrarily, Elo notes the following in "The Rating of Chess Players"

> 1.28 Preservation of the integrity of the rating scale, so that the rating numbers represent approximately the same level of proficiency from one era to the next, is an essential part of the rating system. Just how this can be achieved to a good degree is shown at 3.5.

The current meaning of FIDE ratings can be found in: FIDE Title Regulations effective from 1 January 2022.

**Update** This is not so much an answer as a guide to move forward.

More light is shed on the origins of the Elo rating scale in *Chess Life, Volume XVI, Number 6, JUNE, 1961,p.160, Chess Life and Chess Review Archives*.

> The scale itself is arbitrary. Originally it was designed so that a player who scored 50% in the U.S. Open Tournaments was assigned a 2000 rating and designated a Class A player. With wider participation in this event that, definition of the 2000 rating no longer applies, altho this figure is still used as the middle point of the raling scale and the dividing line between Class A and Expert categories. Currently the timing scale is designed so that its 2000 point center is just ten times the "standard deviation" of the chess population, which by definition has been set at 200 points.

A good start is also, Wikipedia, Elo rating system, Ratings inflation and deflation.

In the ideal world Federations maintaining a rating pool should explain how the rating scale is managed.

USCF developments can be found in Mark Glickman's World, US Chess Ratings.

**Short answer**: The absolute value of players' Elo rating is determined by the policy of the organisation managing the rating pool.

# Answer
> 1 votes
> What sets the absolute value of players' ELO rating?

This is one of those "Why did you stop beating your wife?" questions. Your assumption is wrong. There is no "*absolute value of players' ELO rating*".

> I read that the "the USCF initially aimed for an average club player to have a rating of 1500".
>
> How does this happen exactly?

In the initial calculation this happens by a simple and easy mathematical process of fitting a normal curve to a dataset. I think you missed the word "*initially*". It was done initially. That does not mean it persists.

> How is it ensured that the average ELO rating doesn't start deviating over time from 1500?

It isn't. It does start deviating over time in very obvious ways. Some deviation is built in via the "k" factor. My "k" factor is 20. If I play a "k" factor 10 player then our rating changes won't match. For that game my rating will change by twice as much as the other player's rating. Similarly when I play a "k" factor 40 player the other player's rating will change by twice as much as my rating.

Also when a Kasparov retires from FIDE rated chess before senility has reduced his rating to the average (whatever that now is) he takes his above average rating out of the system and reduces the overall average.

Looking at the averages for FIDE rated players in October (I haven't yet loaded the November data) we see that they are different for the different time controls:

Standard = 1652
Rapid = 1576
Blitz = 1647

# Answer
> 1 votes
> How does the algorithm that is used in the chess world end up setting this absolute scale?

The algorithms used are described in article 8 of the FIDE Rating Regulations:

> **8. The working of the FIDE Rating System**
>
> The FIDE Rating system is a numerical system in which fractional scores are converted to rating differences and vice versa. Its function is to produce scientific measurement information of the best statistical quality.
>
> 8.1
>
> The rating scale is an arbitrary one with a class interval set at 200 points. The tables that follow show the conversion of fractional score 'p' into rating difference 'dp'. For a zero or 1.0 score dp is necessarily indeterminate but is shown notionally as 800. The second table shows conversion of difference in rating 'D' into scoring probability 'PD' for the higher 'H' and the lower 'L' rated player respectively. Thus the two tables are effectively mirror-images.
>
> 8.1a
>
> The table of conversion from fractional score, p, into rating differences, dp
> \[large table skipped. See original link if you really want to see it\]
>
> 8.1b
>
> Table of conversion of difference in rating, D, into scoring probability PD, for the higher, H, and the lower, L, rated player respectively.
> \[Table skipped\]
>
> **8.2 Determining the Rating 'Ru' in a given event of a previously unrated player.**
>
> 8.21
>
> If an unrated player scores zero in his first event his score is disregarded. First determine the average rating of his competition 'Rc'.
> (a) In a Swiss or Team tournament: this is simply the average rating of his opponents.
> (b) The results of both rated and unrated players in a round-robin tournament are taken into account. For unrated players, the average rating of the competition 'Rc' is also the tournament average 'Ra' determined as follows:
>
> (i) Determine the average rating of the rated players 'Rar'.
> (ii) Determine p for each of the rated players against all their opponents.
> Then determine dp for each of these players.
> Then determine the average of these dp = 'dpa'.
> (iii) 'n' is the number of opponents.
> Ra = Rar - dpa x n/(n+1)
>
> 8.22
>
> If he scores 50%, then Ru = Ra
>
> 8.23
>
> If he scores more than 50%, then Ru = Ra + 20 for each half point scored over 50%
>
> 8.24
>
> If he scores less than 50% in a Swiss or team tournament: Ru = Ra + dp
>
> 8.25
>
> If he scores less than 50% in a round-robin: Ru = Ra + dp x n/(n+1).
>
> 8.3
>
> The Rating Rn which is to be published for a previously unrated player is then determined as if the new player had played all his games so far in one tournament. The initial rating is calculated using the total score against all opponents. It is rounded to the nearest whole number.
>
> 8.4
>
> If an unrated player receives a published rating before a particular tournament in which he has played is rated, then he is rated as a rated player with his current rating, but in the rating of his opponents he is counted as an unrated player.

**\> 8.5 Determining the rating change for a rated player**

> 8.51
>
> For each game played against a rated player, determine the difference in rating between the player and his opponent, D.
>
> 8.52
>
> If the opponent is unrated, then the rating is determined at the end of the event. This applies only to round-robin tournaments. In other tournaments games against unrated opponents are not rated.
>
> 8.53
>
> The provisional ratings of unrated players obtained from earlier tournaments are ignored.
>
> 8.54
>
> A difference in rating of more than 400 points shall be counted for rating purposes as though it were a difference of 400 points.
>
> 8.55
>
> (a) Use table 8.1(b) to determine the player’s score probability PD
> (b) ΔR = score – PD. For each game, the score is 1, 0.5 or 0.
> (c) ΣΔR x K = the Rating Change for a given tournament, or Rating period.
>
> 8.56
>
> K is the development coefficient. K = 40 for a player new to the rating list until he has completed events with at least 30 games.
> K = 20 as long as a player's rating remains under 2400.
> K = 10 once a player's published rating has reached 2400 and remains at that level subsequently, even if the rating drops below 2400.
> K = 40 for all players until their 18th birthday, as long as their rating remains under 2300.
> If the number of games (n) for a player on any list for a rating period multiplied by K (as defined above) exceeds 700, then K shall be the largest whole number such that K x n does not exceed 700.
>
> 8.57
>
> The Rating Change is rounded to the nearest whole number. 0.5 is rounded up (whether the change is positive or negative).
>
> 8.58
>
> Determining the Ratings in a round-robin tournament. Where unrated players take part, their ratings are determined by a process of iteration. These new ratings are then used to determine the rating change for the rated players. Then the ΔR for each of the rated players for each game is determined using Ru(new) as if an established rating.

So, in answer to:

> does it always try to make sure that the mean score is 1500, by adjusting everyone's score uniformly when the mean deviates?

As you can see from article 8.5, "No".

> Or does it simply always assign a particular initial score?

As you can see from articles 8.2 - 8.4 the answer is again "No".

---
Tags: fide, elo
---


# Question
Title: When did FIDE's attitude towards boycotts change?
First off, don't get me wrong. I fully understand and back FIDE's removal of competitions from Russia and Belarus. When one country is invading a neighbour the last thing you want to do is hold a tournament there. I also get the banning of official teams from Russia and Belarus. What I find more problematic is the boycott of all individual players with RUS and BLR federation memberships.

This individual boycott has been taken up enthusiastically by federations. Here is what the European Chess Union say on their official website:

> * Individual players representing Russian or Belarusian federations shall be excluded from all ECU competitions unless they change federation or by their expressed will represent the FIDE flag in rating list\*
> * No trainer, arbiter or official from Russia or Belarus will perform any duty during the forthcoming European Chess Championships or in any subsequent ECU events
>
> \*official application to FIDE: federations@fide.com

So, individual chess players must officially transfer either to another federation or to FID else they are banned. For trainers and arbiters they are just banned. No mention of a possibility to change federation for them.

As this thread on the English Chess forum makes clear this also applies to children in England wanting to play ECF events.

Meanwhile I remember when the FIDE website had warm fuzzy words about "gens una sumus" and being against boycotts. I think that was on their "Ethics" page but I can't find it any more. That seems to have changed.

Nevertheless, FIDE was against boycotts as recently as December 2020. I did find this paper, Resolutions for the 2020 FIDE General Assembly, which amongst other things said this:

> **THIRD RESOLUTION**
>
> **Congress notes**: The continuing boycotts by Iranians of Israeli players in chess and other sports, most recently at the World Junior 2019 when GM Mohammad Amin Tabatabei and IM Aryan Gholami refused to play.
>
> **Congress notes**: The resolution of the ECU passed unanimously at The ECU General Assembly, meeting in Skopje on March 23rd, 2019 requesting of the FIDE Presidential Board:
>
> * A statement that such individual boycotts will no longer be tolerated.
> * A resolution from the Board banning the practice of ‘special pairings’ at the Chess Olympiads, FIDE tournaments and in all FIDE rated events. This refers to the practice of deliberately keeping players or teams from certain countries apart by adjusting the pairing software.
> * If required, to take such steps at the next General Assembly to ensure the two points above are on the agenda for the next FIDE GA.
>
> ... **Congress requests**: The Iranian Chess Federation to ensure no future boycotts.
>
> **Congress requests**: The Iranian Chess Federation to instruct its players to compete against all nations in FIDE.

Two years ago it wasn't all right for Iran to boycott individual Israeli chess players, including children, but now it's not just OK but required to boycott all Russian and Belarus players, including children?

I also don't understand why Russian invasion of Ukraine is wrong at the same time as the Uyghur genocide is OK. Both seem despicable to me. But that would be a separate question. Being cynical I suppose that has something to do with the central role Russia and Ukraine have played in world chess over the last hundred years. It's harder to brush under the carpet.

# Answer
Media coverage, and an increase in boycotts around the world are the underlying cause. When Russia invaded Ukraine, the United States took action and many Americans refused to even drink Russian Vodka. It’s a shame that the Uyghur genocide didn’t receive much attention, but the fact is that boycotts are trendy right now and Fide is an organization like any other company. Fide is not against or for boycotts, they are only for making money, and shielding their public image.

Back in 2020 there was a negative attitude towards similar boycotts. The general feeling was that it’s a game and it shouldn’t involve politics. The seriousness of the Russia situation (nukes) sort of made people forget their sportsmanship.
> 1 votes

---
Tags: fide
---


title: Why doesn’t classical atomic exist?

text:
# Question
Title: Why doesn’t classical atomic exist?
Every player rated over 1700 pretty much flat out refuses to play slow games of atomic chess. I understand that it has something to do with white’s first move advantage, but still, there’s no community whatsoever.

There’s around 10,000 active players on lichess and not one wants to play a game longer than 5 minutes. When I take my time during 5+3 games I’ve had players resign and switch to bullet.

I’ve long yearned for quality games of atomic chess but I seem doomed to consume vapid pre move garbage like the rest of us.

# Answer
There would be a number of reasons for this; however this question is going to continually struggle to get Non-Opinion based answers based off the nature of the question.

**Viewability:**

Like most sports and games, variants aren't predominately successful as there has to be an entire new set of rules to follow. New level or understandings, the requirement to develop an entire market, build a fan base.

**Technical Interest:**

If a person has dedicated 10 hours a week for the past 15 years, variants aren't usually that interesting other than as a novel exercise. In most instances chess variants though very similar aren't as technically engaging (at least in my opinion and anecdotal experience of other FM to GM players).

**Ability to determine a exact path:**

The biggest problem is probably here. There are chess variants that have effectively been Brute Forced, and solved. At which point, it is Vaudeville.
> 2 votes

---
Tags: atomic-chess
---


title: Did Kasparov and Karpov reconcile?

text:
# Question
Title: Did Kasparov and Karpov reconcile?
Did Kasparov and Karpov reconcile? In “On My Great Predecessors” Vol. V, Kasparov refers to Karpov very familiarly, as "Anatoly" or even "Tolya." He refers to Korchnoi (a much older player) formally, as Viktor Lvovich. I don't speak Russian, and I don't know if using a given name and nickname are signs of friendliness or just indicate the speaker knows somebody well. I do know that Kasparov and Karpov disliked each other intensely for a long time. I wonder if their relationship changed?

# Answer
There have been several phases in their relationship.

Until the late 1990s, their rivalry is well documented.

When Karpov gradually retired from high-level competition, there was a time of mostly ignoring each other. In his opus "Garry Kasparov on Modern Chess" (4 volumes) written between 2007 and 2010, Kasparov praises Karpov the chessplayer :

> ‘His deep, infiltrating style, subtle positional feeling, and extraordinary persistence, practicality and flexibility rapidly raised him to the very summit of chess.’

> ‘Anatoly Karpov is one of the greatest epoch-creating players of the late 20th century, and his contribution to our knowledge of the subtleties of the ancient game is truly invaluable.’

But he also repeats his accusations of spying and unfair backdoor manoeuvring during their matches.

Because *"the enemy of my enemy is my friend"*, Kasparov nonetheless supported Karpov's bid for Fide presidency in 2010, emphasing on the importance of beating Kirsan Ilyumzhinov. Yet Ilyumzhinov was reelected in muddy conditions.

With the involvement of both champions in Russian politics in the 2010s, their relationship has worsened to such a point that a reconciliation seems totally impossible nowadays.
> 4 votes

# Answer
Back in the day, Karpov and Kasparov were the greatest chess rivalry. After their chess careers ended, there was nothing that really brought them together. Karpov is a Putin apologist and Kasparov is very anti Putin, they do not have much in common in their social lives. They are no longer enemies but they never really became friends either.
> 1 votes

---
Tags: history, world-championship, kasparov, karpov
---


# Question
Title: What is the status for EIGHT piece endgame tablebases?
An earlier question here asked in 2012 about the status of 7-piece tablebases. Today complete 7-piece tables are widely available.

So today, what is the status of 8-piece endgame tablebases?

* How complete is the solution?
* Where are they available? (especially for free)
* What interesting results have emerged so far?

UPDATE:

Here in Chessbase is an interview dated Nov-2022 with Marc Bourzutschky which indicates the status is perhaps halfway complete.

# Answer
> 18 votes
---

Interesting points:

1. The longest sequence so far is 584 moves to win.
    * In the 7-piece tablebase, the longest sequence is 549 moves, so it is surprising that the 8-piece tablebase is not too much longer.
    * This sequence involves white having 2 dark-squared bishops, so it is not a position that is likely to occur in real games.
    * They are confident that they've examined the longest sequences in pawnless endgames, but they may still find longer sequences in endgames involving pawns (such as the 584 moves to win position).
2. The incomplete database is too large to feasibly share at the moment.
3. A new, interesting full-point zugzwang position has been discovered (FEN: 3R4/8/2q5/8/8/2k1r3/2r5/1R1K1Q2).
    * If it is White to move, Black can force a win, if it is Black to move, White can force a win.
    * Marc is interested in such positions which do not involve pawns, knights, or promotions. No such position was found in smaller tablebases, but there is one in the 7-piece tablebase that comes close (it involves two same-colored bishops and thus requires an under-promotion to reach).
    * Thusfar, the only other known position matching his criteria was a ten-piece study composed by Javier Rodriguez Ibran (FEN: 8/8/8/8/8/B6b/1r4R1/1rkqQKR1).

# Answer
> 13 votes
We are still far away from the solution. Estimates for the size of the completed tablebase are around 10 Petabytes. Compare that to the 140 Terabyte hard drive (later trimmed down to 18TB in the syzygy table) and we are still not anywhere near achieving it.

I don’t think that it couldn’t be done this year however, my gut tells me that it’s more due to a lack of trying. Supercomputers are rarely used for chess anymore and someone would have to convince probably a billionaire to “waste” millions of dollars worth of super computing time to achieve it. Once the tablebase is finished, how does one profit off it. Will they even get their money back?

The most interesting find to me at the moment is this world record 8 piece 584 move forced checkmate. It was found by Marc Bourzutschky last year in as far as I can tell the most recent attempt at the 8 piece tablebase. It contains 2 white dark square bishops.

```
R7/8/8/8/7q/2K1B2p/7P/2Bk4 w - - 0 1

```

---
Tags: engines, analysis, endgame, tablebases
---


title: Strange modern defense

text:
# Question
Title: Strange modern defense
I was playing with the white pieces yesterday and faced this opening frequently!

```
[FEN ""]
1. d4 g6 2. c4 Bg7 3. Nc3 e6 4. e4 Ne7 5.Nf3 d5

```

This opening annoyed me because during the whole game I didn't know what to play for. I couldn't identify a plan such as a pawn break, control a square, exchange certain pieces, etc. Let me know if you have any ideas for how white should face this, and what Black is aiming for in this pawn structure in general. I'm flexible to change my move after 3.Nc3. I was considering to play this

```
[FEN ""]
1. d4 g6 2. c4 Bg7 3. Nc3 e6 4. Nf3 Ne7 5.g3 d5 6.cxd5 exd5 7.Bg2

```

If Black plays 7...c6 in this position, then I end up with a carlsbad structure on the queenside and a fianchetto pawn structure on the kingside which I don't know if it's a good idea. My idea was to go for a minority attack and the light square bishop will help on the long h1-a8 diagonal as if it's an English opening.

# Answer
I would like to see the game that you played in the first line, because the opening position that you shared looks very appealing to me to play as the White pieces. I will highlight a few lines (3-4 moves further) to show different plans that White can have here.

---

# Modern Defense against 1. d4 (After 10 known plies)

The analyzed position is after 10 plies, and we can reach this position in a variety of ways. Note that we are not discussing the moves until this point, just figuring out plans to proceed, both for White and Black.

```
[FEN ""]
1. d4 g6 2. c4 Bg7 3. Nc3 e6 4. e4 Ne7 5. Nf3 d5

```

## Pros for White

* Great presence in the center
* More active developed pieces
* Open lines for the Bishops

## Pros for Black

* Strong dark squared Bishop on the long diagonal
* Very close to achieving a safe position for the Black King
* Fair claim to the center after the d5 push, asking White how he wants to proceed

---

## Sixth move options to consider, with basic ideas

### 6.e5

This option seems the most appealing to me. The idea is to immediately try and block the fianchettoed Bishop, and gain spatial advantage. Black's best response is c5, trying to disrupt the pawn chain on the long diagonal, hitting at d4. Another viable response is castling, and then see what White does.

#### 6..c5 line

```
[FEN ""]
1. d4 g6 2. c4 Bg7 3. Nc3 e6 4. e4 Ne7 5. Nf3 d5 6. e5 c5 7. dxc5 Nd7 8. Bg5 Nxe5 9. cxd5 exd5 10. Bb5+ N5c6 11. O-O O-O

```

Note that 7..O-O and 7..Nc6 are also viable, and you should explore those lines as well. But here, we essentially get an active position, and a clear target in the Black camp in the form of an Isolated Queen's Pawn. Note that Black will try to advance the IQP and use it as a menace, and White needs to be a bit careful as well, but studying IQP middlegames will definitely help here.

#### 6..O-O line

```
[FEN ""]
1. d4 g6 2. c4 Bg7 3. Nc3 e6 4. e4 Ne7 5. Nf3 d5 6. e5 O-O 7. Bg5 dxc4 8. Bxc4 h6 9. Be3 Nf5 10. Qe2 Nd7 11. O-O-O

```

White can plan development eventually leading to safe Queenside castling, and following it up with an eventual Kingside pawn storm, which should break through more easily, as Black has already made weakening pawn moves on the Kingside.

### 6.cxd5

This is probably the most flexible option for White, and after exd5, a lot of options are available, including e5, Bd3, exd5, Bb5+. Skipping posting a line, as the viable tree is very thick, and some of the main options, lead to transposed lines as well.

### 6.exd5

Taking with the e pawn doesn't appeal to me personally, but is definitely viable here, as shown.

```
[FEN ""]
1. d4 g6 2. c4 Bg7 3. Nc3 e6 4. e4 Ne7 5. Nf3 d5 6. exd5 exd5 7. cxd5 Nxd5 8. Bg5 Nxc3 9. bxc3 Qd6 10. Bc4 O-O 11. O-O

```

Interesting position for the middlegame, White has more activity, and a semi-open b-file to focus on, while Black can maybe try to attack the weak pawns on a and c files.

### 6.Bg5

After this move, a move like h6 is definitely on the radar for Black, but assuming that the idea behind d5 was to challenge the e4 pawn, we explore the dxe4 line here.

```
[FEN ""]
1. d4 g6 2. c4 Bg7 3. Nc3 e6 4. e4 Ne7 5. Nf3 d5 6. Bg5 dxe4 7. Nxe4 Nbc6 8. Qd2 f5 9. Nc3 Nxd4 10. O-O-O c5 11. Nxd4 Qxd4 12. Nb5 Qxd2+ 13. Rxd2

```

Queenless middlegame, where White's pieces are clearly more active. Black is temporarily up a pawn, which White can win back if it wants, but maybe playing for activity and attacking a King stuck in the center is a better plan here.

### 6.Bd3

c5 is the best response to this, but mainly I see players taking on c4 after this move to gain a tempo on the Bishop. However, it is not in Black's best interests to take here.

```
[FEN ""]
1. d4 g6 2. c4 Bg7 3. Nc3 e6 4. e4 Ne7 5. Nf3 d5 6. Bd3 dxc4 7. Bxc4 O-O 8. O-O Nbc6 9. Bg5 h6 10. Be3 f5?

```

I don't see any good moves for Black after 10. Be3, maybe I'm missing something, but I evaluate this position as very passive for Black, with great chances for White.

### 6.h4/6.Bf4/6.Qa4+/6.Qc2

* All seem viable options, and can be explored further

---

# Conclusion

The opening discussed can take many different paths, with lots of ideas that can be discussed, but from White's perspective, identifying when to resolve the central tension, and developing the Bishops actively on the 4th or 5th ranks seems to be the key here. It should be easy to get to the middlegame with more actively developed pieces, and try to press for an advantage.
> 3 votes

---
Tags: strategy, modern-defense
---


# Question
Title: Scid not registering multiple sub-variations
I am trying to save multiple lines in the same game, like the following:

1.e4 1..e5 (1..c5 2. Nf3 (2.Nc3)) 2.Nf3

However, when I try to do this, it is only allowing me to keep either 2.Nf3 or 2.Nc3 after the c5 line. I do remember being able to save multiple lines earlier on another laptop of mine.

Note that I am able to save multiple lines where the first move of the variations are different, like:

1.e4 1..e5 (1..c5) (1..c6) (1..e6)

My About Scid section:

# Answer
> 1 votes
Finally found the solution to this on ScidWiki

---

***To explicitly add a new variation starting with the same move (e.g. to simplify deeply nested variation trees) press Ctrl-A to explicitly add a variation and only then play the move.***

---
Tags: software, scid
---


title: Should I get into the Najdorf?

text:
# Question
Title: Should I get into the Najdorf?
I'm a ~1500 rated player on Chess.com's scale (highest rating is 1420 or so, but rapidly growing so we'll say 1500). A few months ago I participated in an invitational tournament against another school's club, and in the month or so beforehand I got Colovic's Short & Sweet Najdorf course on Chessable. I ended up playing 2 games in the Najdorf, both of which I won against some pretty good intermediate players. I ended up winning with a score of 4.5/5.

Recently though I bought Logozar's Najdorf course (also on Chessable) and it has around 150 lines. I don't know how long it would take to complete a course like that, but I'd probably better spend my study time on tactics and strategy. I really like it though, as it has spectacular winning chances for Black and you can really punish your opponent if they don't know what they're doing. If I was higher rated (1700-2000) I would definitely sink the time into learning it.

My question is: how long does it usually take someone to learn a 150-line Chessable course, and is it worth the time to learn an opening I really feel at home in? If not, are there any other defenses against e4 that offer similar themes but are easier to learn/less sharp (i.e. no English Attack)?

# Answer
In regards to to learning the Najdorf. I would say probably approximately month to learn...a lifetime to master

Coming from the direction of a chess coach. No. Don't focus on openings if you are under 2000 elo.

More likely your games and results will significantly improve by focusing on End Game and Middle Game, Tactics and training depth. The amount of players under 2000 that don't know how to effectively mate with a King, Bishop and Knight is just absolutely astounding

By all means play with the Najdorf , learn the overall theme, but you will benefit more learning and locking the other aspects of the game before locking down openings.
> 1 votes

---
Tags: opening, sicilian-defense, najdorf
---


# Question
Title: Differences between normal chessbase and chessbase Steam
I just recently realised that the chessbase software is available on Steam, which would seem normal to me if it wasn't almost half the price compared to the version on the official website. I have chessbase 16 and chessbase 17 is on offer but I don't want to pay for a cut-down version, do you know if there is a difference?

# Answer
My understanding is not much of anything unless you are a power user. I do believe there are issues if you intend to use things like the Mega Database etc. ultimately it's just a licensing thing.

In all honesty I wouldn't generally recommend Chessbase. This is from someone who owns it, uses it extensively, has a dedicated server just doing analysis.

There is nothing in Chessbase that something like SCID cannot do for average user.
> 3 votes

---
Tags: engines, software, database, chessbase, study
---


title: Playing blind chess with aphantasia

text:
# Question
Title: Playing blind chess with aphantasia
> Aphantasia is the suggested name for a condition where one does not possess a functioning mind's eye and cannot visualize imagery.

Everyone's a bit different. I have a cubics cube on my desk, and then trying to visualise it after closing my eyes, at my best, I see something like the two picture on the right below (and that's really pushing it). At my worst I cannot visualise anything at all.

The images I see are certainly of zero use for any calculation. I can play tic tac toe in my head, but without visualising it. Same goes for a 4x4 chess board and a Knight hopping all over it. I just intuitively "feel" where the squares are in relationship to each other, but I don't "see" anything really.

On the other hand I am very good at manipulating 3D objects inside of my head. If I think of a church, I can rotate it, skew and stretch it and adjust for perspective (Perhaps because I'm a 3D modelling veteran) but it has no color, it isn't an "image", it's just 3D data. Hard to put into words.

Is there any chance, a guy like me could ever learn to play blind chess?

# Answer
Yes, you can learn how to play blindfold chess! It's not easy, so you'll have to put in the effort and train your visualization. "Visualization" in this context means your ability to have a mental representation of the board enabling you to calculate and make moves. A **common misconception** is, that you need to have a **graphic view** of the board as if you were seeing the board on a computer screen.

This is not the case. More important is to have the memory and "feeling" for where the pieces are and **what squares they control**. Therefore, your Rubik's cube analogy is not appropriate to determine your blindfold chess ability. As long as there is no problem with your memory in general, you should be able to play blindfold chess. The placement of and relationship between the pieces (including controlled squares) is what most blindfold players/masters have in their minds. It is absolutely crucial to know each and every diagonal and what squares lie on that diagonal without thinking. The same goes for the colour and name of a square. You should also be able to maneuver knights blindfolded. When I play blindfold chess, I find it helpful to keep mental notes in mind, such as "White's bishop on g2 is attacking my knight on c6".

Being a strong chess player helps a lot because many patterns and pawn structures are known / easy to remember and to play ("Karlsbad, both sides castled kingside" is far easier to remember than "White pawns on d4, e3, ..."). It can also help to always vocalize moves ("knight e4") even when playing online alone because it serves as a memory aid ("the knight is on e4, isn't it").

There are a lot of resources describing how to train your visualization and blindfold ability, as well as websites and training apps. When you want to test your blindfold ability, you can play while disabling pieces in the settings (or as a first step choose lichess' "disguised" piece style).

As a side note: expect a massive reduction in playing strength (I'm talking about **hundreds** of points). The stronger you are, the smaller the expected rating loss. This is why this is one of the only cases where lichess allows a second account, so that you can play blindfold while maintaining accurate ratings.
> 5 votes

# Answer
I have aphantasia and if somebody says you can play blindfold chess, don't believe them, they probably don't have aphantasia and have no idea what it means. My blitz rating in lichess is ~2100 (without any training). If I had started chess training as a child, I would probably have reached Grandmaster level. But I would never have reached the level of the top grandmasters because I think it's impossible with aphantasia.

Blindfold chess can be played to some extent, through great difficulty, great practice, perhaps being able to play one game at a time without making mistakes. IMO it's not worth the effort.

In short, it is possible to play chess at a high level, whether you have aphantasia or not. But certainly not blindfold chess.
> 4 votes

# Answer
I just figured out that I have aphantasia. I figured it was normal not to be able to see anything when you close your eyes, but apparently not. While it might be a disadvantage, I can play blindfolded chess! When I play it, I have an intuitive sense of where everything is and pattern recognition takes me the rest of the way. Keep in mind I am 2150 Rapid Chess.com, but after working on calculation exercises, I found I was able to play blindfolded. It isn't easy, but it certainly is doable, you just need to train the correct skills.
> 3 votes

---
Tags: blindfold-chess, visualization
---


title: Phone apps for playing chess variants

text:
# Question
Title: Phone apps for playing chess variants
A group of local friends and I have become fairly engrossed in playing a certain chess variant over the last few years. We play on a regular basis; we've coded a program that allows us to play online, and we play over a board in person.

However, there is one situation in which we cannot play, and it is unfortunately the most common one: when we are together in person, but not in front of a board.

In these situations, we have our phones (which are all Android, as it happens). We could use an app that simulates a chess board (letting us put pieces on the board and moving them around without restriction), or an app that just lets you edit the board position (we could "edit" it to make each move as necessary).

We have found an app that allows you to edit a chess board (it is unwieldy and not the intended use of the app), but this is where the "chess variant" part really comes into play: like many variants, not every piece is a standard chess piece.

In this variant, every standard chess piece is used, in addition to one additional piece (one of the rooks is replaced). This piece could be represented by **anything**, as long as it isn't one of the other pieces.

I feel like the most likely solution would be an app that lets you place chess pieces and checker pieces (like a "tabletop simulator" of sorts, where you just place your own pieces and play as you want).

And just to clarify, the app does not need online functionality (although that would be amazing), and it needs to **not** restrict your moves (like most people, we all know the rules and can referee our own games).

So the question is: Do you know of any Android apps which could be used as an impromptu chess board in order to play a variant of chess that includes a nonstandard piece in addition to all standard pieces?

(Disclaimer: If you're interested in the chess variant, details can be included in a comment reply, but I don't want to include this information in the question itself because it is not relevant. For the purposes of answering the question, it should be assumed the chess variant in question is something of our own creation.)

# Answer
There is now an app called Chesscraft on Google play which allows custom boards and pieces. It plays reasonably well.
> 4 votes

# Answer
Since you have gotten no answer in 27 months, I will give you what is most likely only a potential solution. The lichess.org website supports eight variants, and also has a smartphone app.

It's fairly likely that your variant is not covered, but that is not the end of it! The site is 100% open source, and will almost certainly incorporate a variant if someone contributed the time and code.

I hope this answer was better than nothing!
> 2 votes

# Answer
Recently, many chess platforms including chess.com and lichess also allow playing chess variants. Most of them have mobile apps for playing.

## Apps in which you can make variant or play online

Mobile apps to play (or make) chess variants include the following:

There are apps for some specific chess variants (most of them are at creation stage).

## Apps that allow playing offline with friends (or agaist computer)
> 0 votes

---
Tags: software, chess-variants, android
---


title: How to propose a new game variant?

text:
# Question
Title: How to propose a new game variant?
My daughter and I have devised a chess variant which we feel works very well: it **preserves the basic moves and strategies of chess**, yet adds new strategies and considerations. It is a form of "3-D chess", yet not gimicky as the current forms are, possibly because this variant did not start off with the intention to do another "3-D" idea. In fact, the 'stacking' of boards is a late addition to the game and not necessary for the rules to hold. It does help spatially-oriented human minds to relate to the game, though!

In our variant, a transparent (glass) chess board is suspended about 30 cm above another board. **Standard gameplay occurs on the top board, with the bottom board initially empty.** Whenever a piece is captured on the top board, it is moved to the same position on the bottom board. When the capturing piece later moves off the square, the piece below it (if still there) returns 'up' to the top board. Thus, pieces are 'buried' instead of 'captured'.

If a piece already exists in the relevant position on the bottom board, then that piece is then removed from the bottom board and considered 'captured' in the traditional sense. Thus, each position can have only a single 'buried' piece. Furthermore, all pieces on the bottom board *must* have an associated piece above them.

The twist is that a player can take his turn on the bottom board instead of the top board **only if that move results in a capture**. This is a traditional capture: the piece never returns to gameplay. Additionally, the rule that all bottom-board pieces have associated pieces above them is preserved.

The fact that each position (square) can have only a single buried piece makes gameplay very interesting. It becomes strategy to *not* defend pieces as taking an opponent's piece which just took your own piece will mean that your piece is forever captured. Other interesting strategy aspects emerge, such as 'wormholing' through the bottom board or tricking your opponent into capturing pieces that you prefer to have on the bottom board. Gameplay is much longer, but mistakes are more forgiving. To make it easier to find relative positions on the top and bottom board, the following squares have a small dot in the center of the square:

**How might we present this variant for others to consider and enjoy?**

# Answer
The canonical site for publishing a new chess variant is https://www.chessvariants.com. Read some of the descriptions there to get a feeling of the format of presentation, register (it's free) and submit your chess variant. They have an intuitive form that helps you in the write-up.
> 8 votes

# Answer
Nowadayas, there are several websites and mobile apps to make chess variants. For instance, use one of the apps chess remix, Omnichess or chessCraft.
> 1 votes

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Tags: chess-variants
---


# Question
Title: Non chess specific game AI that learns any game and can play chess?
There is another question that asks "Has anyone ever written a chess program that does have insights of its own" that question is about a chess only game AI. I am asking having to learn the rules of the game, pieces, board size, etc. The program should be able to learn any board game, checkers, go, etc. Computers programmed by humans are better at chess than humans. Any computer programmed by itself (via some self learning algorithm, where even the rules have to be learned, i.e. number of pieces, board dimensions, piece move rules, game objective, etc) playing any good at all? Let's ignore that the self learning algorithm would have been devised by a human...

If you know of any such generic game AI engines, please post references to them, at least their name. Thanks!

# Answer
> 2 votes
http://rebelscience.blogspot.de/2011/02/intelligent-computer-chess-part-i.html

This is the blog of a guy who tries to do what you describe: Create an artificial intelligence that learns to play chess purely by trial and error. I don't think he ever got very far. He also believes that the old testament contains coded information on how to create an AI …

It is surely possible to create an AI that learns to play chess from scratch, but I doubt it would ever be any good (Though this General Game Playing stuff doesn't learn the rules, the deepmind company atari AI does.). The reason is that chess is a tactical game and calculating tactics requires extremely optimised code. That's nothing you just stumble into after playing a few million games.

# Answer
> 0 votes
Zillions of Games is a General Game Playing system that plays chess. It was perhaps designed with chess specifically in mind, but in order for the program to play a game, you must first load a zdf file which specifies how the pieces move and what the goal is. It can also play checkers, go, shogi, etc.

The engine Nebiyu running in the GUI Winboard Alien Edition can play checkers, chess, go, reversi, Amazons and a few other games. On Android, there is a program called XO Demo which plays many board games. On iOS, there is an app called Social Games.

The Association for Advancement of Artificial Intelligence holds a General Game Playing competition every year at its conference. The programs are designed to play almost any game, and are not told in advance which games will be played. Each of the programs could play chess if someone wrote up a rule set. I don't think the GGP competitions have ever included chess as one of the games however.

In the context of chess engines, the word "learning" refers to the engine adapting its opening book (book leaning) or evaluation (automated tuning) based on its results. Many engines learn in this sense, eg. Crafty, Deep Thought, Exchess, Gaviota, Junior, MChess, Neurochess, Romichess and Tao.

# Answer
> 0 votes
The 2016 conferece paper "DeepChess: End-to-End Deep Neural Network for Automatic Learning in Chess" by David, Netanyahu and Wolf reports such a learning method.

Quote from the abstract of the paper (emphasis is mine):

> We present an end-to-end learning method for chess, relying on deep neural networks. Without any a priori knowledge, in particular **without any knowledge regarding the rules of chess**, a deep neural network is trained using a combination of unsupervised pretraining and supervised training. The unsupervised training extracts high level features from a given position, and the supervised training learns to compare two chess positions and select the more favorable one. The training relies entirely on datasets of several million chess games, and no further domain specific knowledge is incorporated.

---
Tags: engines
---


# Question
Title: Variation of chess where winner has to capture all pieces?
Is there any variation of chess where the winner has to take all of the opponents pieces rather than just force the capture of one of them ?

I guess sacrifices wouldn't work well in this variation of chess.

# Answer
Horde/Dunsany's chess would match your requirement for one side (the other has to mate).
> 3 votes

# Answer
First of all, the historical rules of Shatranj include the victory condition "bare King", i.e., capturing all pieces except the King is a victory, except that the other player can capture the last piece of the first player immediately after the loss of his last piece (then, the game is drawn).

As a modern variant, there is Extinction Chess (aka Survival of the Species) where the extinction of one piece type (Knight, Bishop etc.) wins the game.
> 3 votes

# Answer
**Capture all** is the chess variant you are looking for.

Chess variant with no check or checkmate. Players win by capturing all opposing pieces.

Presence or absence of king can be set, but even if there is a king, the check-rule does not apply to it, and it can be captured like any other piece (and its picture is different to emphasize this rule).

Otherwise the rules of chess apply, with the following difference: Pawns can also promote to king.

Note: if the player on turn has pieces but no legal moves, it is a stalemate, i.e. draw.

Inventor: Uray M. János (year: 2013)

Source: https://greenchess.net/rules.php?v=capture-all
> 0 votes

# Answer
Back in the 70s/80s when I experimented with Chess Variants I tried what we would call in Italian *Mangiatutto* (Eat-it-all) who was just that: King had no special priviliges and the goal was to take all of the opponent's army.

Basically, checkers played with chess pieces.

Quite dull.

To spice it up we would play it in the fashion of Progressive Chess: White starts with 1 move, Black plays 2, white follows with 3, black with 4 and so on. It got a bit trickier in this way.
> 0 votes

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Tags: chess-variants
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