title: Calculation skills to 2000 and beyond

text:
# Question
Title: Calculation skills to 2000 and beyond
I'm rated about 1900 USCF and have been stuck between 1800-1900 for a few years not really knowing how to break through to 2000+. I have a good amount of positional understanding and solid foundation in tactics, i.e. I've gotten quite good at solving tactics problems.

That being said, I lose a lot of games due to poor evaluation, time pressure, and erratic blunders. I think that essentially everything in chess goes back to the skill of calculation, including things like time pressure, which is due to inefficient calculation.

So then, how do I further improve my calculation? More visualization exercises? Playing blitz until I can't see straight? Mental exercises? I feel like my visualization is already decent, as I can successfully play 3 blindfolded games at the same time (that's the most I've tried at least). I just don't understand what I've been missing out on that improves my calculation. And if it matters, I'm 20 years old.

Thanks!

# Answer
If you can play three games blind-folded, it is unlikely that your problem is calculation. I dare say that there aren't many 1900 USCF players that can do that.

You say you "lose a lot of games due to poor evaluation, time pressure, and erratic blunders". That also doesn't cry out "calculation problems" to me.

In my experience ratings first and foremost reflect positional understanding. Calculation skills make a much smaller difference, at least above a certain threshold.

To be clear, positional understanding isn't knowledge as much as a good feeling for the position. I.e. whether you can precisely estimate how good your position really is and quickly come up with sensible moves and plans. If you are lacking in that department you tend to calculate a lot without achieving much. That results in time pressure and blunders just as surely as having calculation deficits.

So I would rather recommend a book like Positional Play by Jacob Aagaard. If you can easily solve the problems in this book, you can always go back to pure calculation.

By the way, there is a big difference between training calculation and training tactics. Solving tactics depends on seeing motives, training calculation depends on the ability to think far ahead without confusing yourself. So if you do go back to pure calculation, maybe you should try the Calculation book by Aagaard, or similar books by Dvoretsky.
> 6 votes

# Answer
I'll tell you what I did to go from 2000 to 2200. At least 10 chess tempo tactics a day, completing these endgame books (silmans complete endgame manual, dvoretsky's endgame manual, endgame strategy by shereshevsky), went over a few thousand gm games (1-2 guess the move games a day on chesstempo and 6 games a day on 2700chess.com from classical time control games), and played and analyzed at least 1 15+ minute game a day.

If you're 1900 you likely haven't seen enough middle game or endgame patterns (plans and piece maneuvers ), your evaluation abilities aren't strong enough (feeling who is better in a given position), your tactics aren't up to par, you may have trouble recognizing critical moments, and there are probably holes in your black preparation against e4, d4, or c4.

The regimen above will greatly help fix these issues, but it'll take about 3 hours a day. Good luck.
> 1 votes

# Answer
I am in a similar situation, so I can't really give advise from the perspective of someone who has been to the mountain top, and seen the promised land, but.. I suspect the key here is that to immerse oneself in chess, pursuing knowledge and skill, trying to find answers to questions etc, rather than this or that study program.
> 1 votes

# Answer
Practice, practice, practice. Go on ChessTempo or Chess.com and do as many tactics exercises as you can. Performing calculations over and over gradually builds your intuition. When your intuition improves, your implicit calculations abilities improve (meaning you'll be able to play better without consciously trying).

If you want to go further, pick up the Grandmaster Preparation Calculation book. It's excellent, and designed to train players to improve calculation and intuition. The book is useful for anyone trying to reach up to GM level, but it's also fine for your goals.
> 0 votes

# Answer
1900 uscf is still too low of a rating for positional understanding to mean anything. Most likely your tactics are still too weak. 2200 should not be a problem for players with sufficient tactical abilities but weak positional understanding.
> 0 votes

# Answer
**This sounds like a combination of problems.** If you are losing due to "erratic blunders" and "time pressure" you are either lacking focus or are thinking incorrectly (or as you say "inefficient calculation").

> You should read "Think Like a Grandmaster" by Kotov

This book teaches you how to enumerate candidate moves and tackle branching variations in the most efficient way.

"I lose a lot due to poor evaluation". And it is your difficulty in evaluating positions that is probably leading to your time pressure. Blitz and tactic puzzles are not going to help your evaluation skills.

> You need to read over GM games annotated by the players

Getting GM insight into how they evaluate their games will do wonders for your game! I recommend "Symslov's 125 Selected Games", "Zurich International Chess Tournament, 1953". "Fire on Board" by Shirov, etc.
> 0 votes

---
Tags: learning, calculation
---


title: Is this a stalemate?

text:
# Question
Title: Is this a stalemate?
The gamepigeon app is declaring I lost (I am black). This simply does not make sense since it is white's turn and they are in check. The game abruptly ends.

Is this erroneous logic? How can I lose if I am not in check?

# Answer
This is a **bug**. The GamePigeon app was written by non-chess programmers, their focus is not on chess. They're not specalized in chess apps, chess is just one of the many things they do.
> 7 votes

# Answer
Well, the app was wrong to declare the game over at that point. But it is a losing position for black.

```
6Q1/8/7R/8/4P3/1P3K2/P4P1n/7k w - - 0 0

1. Rxh2 Kxh2 2. Qg2#

```

Notably, white needs to be careful, as most king moves immediately lead to stalemate and a draw.

I think I also understand what the bug in the app is. It's been programmed to check every position to see if there is a side with no legal moves. If there is, that side is declared the loser. That's what it sees here - no legal moves for black, so black loses. Never mind that it's not even black's turn (so it doesn't matter if he has moves or not), that it couldn't possibly be black's turn because white is in check, or that in general, "no legal moves" can be a stalemate just as well as a loss.
> 4 votes

---
Tags: endgame, draw, stalemate
---


title: What's a fun troll bughouse opening?

text:
# Question
Title: What's a fun troll bughouse opening?
I have been playing e3, Ke2, Kd3 openings in the bughouse chess variation on chess.com.

I got to 1800 pretty easily. I'm looking for other openings to play. As a side note, pushing down a4-a5-a6 is actually pretty strong.

# Answer
> 4 votes
Sacrificing a piece on f7 (via Nf3-g5-f7 or e4, Bc4, Bxf7) creates a hole on f7 which can later be filled by a parachuting piece. This can be quite effective particularly if you have paratroopers ready from your partner's game.

---
Tags: bughouse
---


title: Bughouse defense patterns

text:
# Question
Title: Bughouse defense patterns
What defensive patterns and structures are used in Bughouse and Crazyhouse? I've heard that castling is rarely useful, but what should be done instead? My defensive play usually boils down to huddling in the "turtle formation":

```
[FEN "2rqkr2/pppbbppp/2nppn2/8/8/8/8/8 w KQ - 0 1"]

```

<sup>*Turtling exaggerated for dramatic effect*</sup>

This is entirely ineffective and quickly results in mate.

How can I defend in bughouse?

# Answer
> 3 votes
In general, in a bughouse game, one of the players in the team attacks while the other team member defends. Thus, when the defender gets attacked, the attacker sacrifices a lot of material. This material goes to the other team member (attacker), who can the use the material to fuel their attack. Thus, the defender loses (or saves) the match. Defensive strategies are therefore very important indeed.

The key square is usually the f2-square for white (f7 for black). Let's focus on black defending, since that is usually the case. Thus, the f7-square is critical. White will sac a bishop on f7, drop a knight on g5 and something diagonal on f7, leading to a quick win. The basic idea is to defend with e7-e6, blocking the a2-g8 diagonal. Yet, white can drop a pawn on f5 or sac a knight on f7 and drop a second knight on g5.

The main problem is that white can drop a pawn on h6 and open up the g7 and f6 squares for attack. If black plays h7-h6, then white drops a pawn on g6, attacking on f7. If you have to castle, then usually kingside is preferred, since queenside is vulnerable to a heavy piece dropped on a8 followed by a knight getting to a7. Also, a white pawn getting to a7 with a black king on c8 is a killer. Kingside castling makes the pawn drop on h6 perhaps even more deadly. Also, h7 starts becoming an issue.

So, here are a few tips how to survive as black against white attacking:

1. Drop an extra pawn on h6, so you get an f7, g7, h7, h6 pawn structure.
2. Play e7-e6
3. Drop a bishop on g8 to support f7
4. Always have a pawn, bishop or knight on f7 (never the king)
5. Drop a pawn on f6 (after getting a pawn on h6) getting more control over g5 and e5 (where white tries to place a knight)
6. Be ready to sac a queen on a white knight on g5 to buy time
7. Never move the c-pawn or f-pawn. In general, avoid any pawn moves, unless you are sure about what you are doing. After the c-pawn moves, c7 and d6 become weak, which is simply lethal.
8. Exchange your bishops for the opponent's knights by pinning them to the enemy queen or king (check with your team mate if knights are good). In general, keep those enemy knights pinned. E.g. drop a bishop on h5 to protect on f7 and pin the Nf3 to Qd1.

# Answer
> 2 votes
FWIW, I am not a good bughouse player, but that may be more due to my poor blitz play.

It is better to be aggressive and attack in Bughouse, If you are attacking on both boards, you will likely win, and yet, both white and black have to be concerned with defense, as dropped pieces can start an attack out of thin air. The best defense is a good offense even more so in Bughouse.

Dropped pieces, sacrifices to draw the king out, and dropped pawn chains are the usual modes of attack. The six squares a knights move from your king, the back rank, and the f7 (f2 for white) are the key squares to occupy and guard.

Squares are more important than lines in Bughouse. Lines are easily blocked by dropped pieces and squares are easily used by blocked pieces.

Development is important in Bughouse like regular chess, both for attack and defense. Your pieces on the board are your first line of defense against dropped pieces.

You want to move as few pawns off their starting squares as possible, and try to play with pieces. Pawns on the attack are usually dropped.

Piece values are quite different than regular chess. Pawns are more important and long distance pieces less. Also, the values are even more dependent on the board position than in regular chess. I would give as an approximation P-1, B-2, R-2, N-2.5, Q-5

A piece in the hand is worth two on the board.

# Answer
> 0 votes
Castling has always worked well for me, but the pawns in front of the King should never be moved, even for a fianchetto. It gives the opponent targets for sacrifices and weakens the control of key squares near the King. A pawn or a piece would then have to be dropped defensively later to patch the holes ; it will waste a turn and let the opponent attack, which isn't something you want in bughouse.

---
Tags: defense, bughouse
---


title: 1900 rating with no progress

text:
# Question
Title: 1900 rating with no progress
I have been around 1700-1900 rating (glicko 2) for a while. I have been losing on tactics when there aren't many pieces left.(mid-end game) My positional thinking is alright, and my endgame skills are alright. I play king's pawn with white and caro-cann + queen's indian for black. Also I have big strikes. On a good day I can win 5 in a row, on a bad day I lose 5 in a row. How can I improve my rating?

# Answer
> 3 votes
Do tactics regularly (possibly every day). Below 2000 rating is probably the best thing you can do, especially if you have a weak point there.

Ideally you want to practice for ~20-60 minutes (depending on how committed you want to be) on problems that do NOT give away the theme of the tactic involved (e.g. "exchange sacrifice", "overload", etc).

Another thing you can do is to review your games, and if you lose due to tactics try and figure out which was the best response to parry that blow. In any case reviewing your own games is the key to improve (first review them on your own, and once you're finished go through them with an engine).

Finally, I think you might want to watch other people playing, especially ranked 200-400 higher than you, and then review those games as well. I find it very useful because I usually understand the reasoning behind moves I didn't think about during my own games.

---
Tags: learning
---


# Question
Title: Is there a freely available online 7 piece Endgame tablebase?
The only 7 piece site I heard about is http://tb7.chessok.com/ , and upon registration I am able to setup various positions with 2-6 pieces . However as soon as I setup a position with 7 piece, I get an error about service not being avaiable. Has anyone had better luck or know of any other site with 7 pieces tablebases?

Update: in the end I discovered that FinalGen solved a vast majority of positions I was interested in, included those with more than 7 pieces. http://finalgenchess.ovh/home\_ing.php

# Answer
> 17 votes
### Original Answer:

7-men Lomonosov is free as an Android application.

---

### Update - September 2018:

7-men Syzygy is available for free. Also available from Lichess.

# Answer
> 7 votes
http://chessok.com/?page\_id=27966

History Note

The first ending tablebases - for all 4-piece endgames - were built by the end of the 80-s. In the beginning of the 90-s, the same task was done for 5-pieces. In 2005, 6-piece endings were solved in Nalimov Tablebases which are now used by many professional chess programs and services.

Experts didn’t expect 7-piece endings to be cracked and catalogued until after 2015, but Convekta Ltd, namely programmers Zakharov and Makhnichev - the developers of the Aquarium interface - managed to solve this task in just 6 months using a new algorithm designed specifically for this purpose and run on the Lomonosov supercomputer based in the Moscow State University. Lomonosov Tablebases

As a result, we now have 525 tablebases of the 4 vs. 3 type and 350 tablebases of the 5 vs. 2 type. The calculations for 6 pieces playing against a lone king weren’t done because the outcome is rather obvious.

The total volume of all tablebases is 140 000 gigabytes, which is obviously too much for personal computers. Lomonosov Tablebases will be accessible online from the Aquarium interface and on the chessok.com website. All users of ChessOK Aquarium, Houdini Aquarium and Chess Assistant products get free access to the service for the period specified in their product description.

# Answer
> 5 votes
The 7 piece EGTB is not yet freely available online, as far as I know. Building the tablebase is costly in time and resources and the storage space is not cost-free either.
Concerning http://tb7.chessok.com/ do not be too disappointed, because they mention this explicitly (at least today, maybe not on April 11th when you tried):
"*Currently the tablebases are only accessible by legal owners of Chess Asssitant 14, ChessOk Aquarium 2014 or Houdini 4 Aquarium. Later, more users will be able to use the service.*"
And on their signup page:
" *After registration you will be able to:
probe 6-man ending tablebases;
(...)
probe 7-man tablebases (license key required – see the next page).*"

# Answer
> 4 votes
https://syzygy-tables.info/ allows to look up 7-men endgame positions. It does not give DTM information for 6- and 7-men endgames, only DTZ50+. On one hand, it is compliant with 50-move rule, OTOH, DTZ50-optimal play can be ugly (if it is possible to push a pawn or sacrifice a piece, it will).

Also available for download: https://tablebase.lichess.ovh/tables/standard/

---
Tags: software, endgame, tablebases
---


# Question
Title: Is there any UCI engine that presents DTZ information from syzygy in analyse mode?
Many UCI engines that can read syzygy database put same score for every winning move (#1000 in komodo, +123.53 in stockfish, ...) and you have no idea how to make real progress when analysing root positions with them. **Is there some UCI engine that scores move based on dtz value?**

I understand that this dtz value is something new and that it doesn't fit very well to standard way moves are scored by engines, but without this dtz value engine becomes useless when material is reduced to 6 pieces.

# Answer
> 1 votes
Stockfish has an undocumented, non-standard command "d" which prints, among other things, the DTZ value. Some interfaces, for example, Arena, let the user give commands to the engine manually.

---
Tags: tablebases, uci
---


title: Team League North America

text:
# Question
Title: Team League North America
In Europe, each country organizes a team league, which are known highly competitive like Bundesliga in Germany or Top 12 in France as an example.

Is there similar competition in North America (Canada, US) inside the states?

# Answer
> 1 votes
Yes there is a chess league in the US, but it does not have the sponsorship you see in Europe. Check the USCF website, and this more specific site http://uschessleague.com/

---
Tags: team
---


# Question
Title: Book recommendations on Pawn Endgame for intermediate and advanced level players?
I just started preparing Endgame using Dvoretsky Endgame Manual. I am wondering if there are more books online about Pawn Endgames that I can use side by side either as an additional study material or solving book. Thanks.

# Answer
> 3 votes
*Chess Endgame Training* by Bernd Rosen features 16 sections on different types of endgame, with 5 of them focused on pawn endgames. Each section has around 16 puzzles to solve featuring different themes : zugzwang, space advantage, pawn break, and so on. Some were quite tricky to solve (I'm ~1850 FIDE) and the author's lines and insights were helpful, even though I already knew basic endgames.

FYI, I haven't read Dvoretsky's Endgame Manual so I can't guarantee you there's no redundancy, but I'd say it's unlikely. Rosen also divided material by section and within sections, which helps focus on particular themes for practice.

# Answer
> 2 votes
If you can find it *The Final Countdown* by Hajenius and Van Riemsdijk, also Muller and Lamprecht with *Secrets of Pawn Endings*.

*The Final Countdown* is a little book from the 90s that discusses pawn endings and things like key squares, and corresponding squares. It has about 50 exercises at the end.

*Secrets of Pawn Endings* is very comprehensive and has exercises with solutions for every chapter. It covers all sorts of concepts and also goes into different thinking methods.

An older book is Comprehensive Chess Endings, volume 4. I haven't read it so I don't know what it contained in the way of exercises, but Averbakh's series was well regarded when it was in print.

I have Fishbein's book, but I haven't read it. If I had to choose one, I'd say you probably can't go wrong with *Secrets of Pawn Endings*.

# Answer
> 2 votes
Reuben Fine's Basic Chess Endings is a classic - Benko's revision corrects errors in the early edition

# Answer
> 1 votes
Encyclopedia of Chess Endings, Volume 1, Pawn Endings by Aleksandar Matanovic

The ECO books are thick and considered the standard reference books for all phases of chess. They have a wide range of very specific books from the pawn ending you seek to anything like Rook vs. Minor Piece Endings, or Queen and Pawn endings. The drawback of these books is that they don't have detailed explanations of the lines, but they are meant to be comprehensive.

# Answer
> 1 votes
Alex Fishbein's King and Pawn Endgames has made me feel comfortable seeing only pawns on the board.

The book is filled with almost 300 positions.

I have only gone through the first 60 and I already feel ages ahead of my ability. No longer do I have to look at a King and Pawns only endgame in horror. I actually have ideas about what to do (king in the middle, forcing the enemy king onto a bad square, gaining tempo, etc.)

I have brilliantly developed an intuition for the king. I tend to move my king towards the middle in late middlegames.

---
Tags: endgame, books, pawn-endgame
---


title: Blunder checklist for strong playrs

text:
# Question
Title: Blunder checklist for strong playrs
I find myself having to use checklists of really simple stuff (like going over all captures, checks, threats, tactical themes, changes after a move) quickly in order to avoid very basic oversights from happening. Having to resort to this is of course quite discouraging, and I'm asking myself if the necessity to do so disappears as one grows stronger. So, do strong players (let's say rated 2200 and above) use such checklists?

# Answer
Disclaimer: Every person has their own way of approaching these situations, but I think my experience is similar to the experience of most other (stronger) players.

In an implicit way everyone uses a checklist as you do. Weaker (or more unexperienced) players, maybe need to mentally go through all the points in order, whereas stronger (or more experienced) players are able to do so automatically at every move. When my opponent moves a piece, I automatically check which of my squares and pieces are now attacked and create a threat to me. Similarly I also check which squares are now less defended and if that opens an opportunity for me. Similarly I check for king's safety, tactical motives and other opportunities. This is however not explicitly checking if there is, for example, a fork attack pending, but more the realization that two pieces are in a position where a fork attack might happen (regardless if it is currently possible or not).

Nevertheless I sometimes take some time to evaluate the whole situation on the board. This includes tactical motives but rather focuses on strengths and weaknesses of my position and my opponent position, ideally leading to a plan that can later be executed. Here I often fall back to a checklist, looking for common features such as weak pawns, inactive pieces or open lines and diagonals.

As advice for you, there is no shame in trying to avoid blunders. If you have to look explicitly for tactical motives, then do it. With time you will get used to the most common patterns and find them more easily and quickly. Maybe you will also be able to find these patterns "by heart" (that is without having to look for them). But even if not, your opponent will never know and your strength doesn't come from the way that you look for blunders, but how effectively you can identify them.
> 3 votes

# Answer
1) Material presence 2) Direct threats. This includes any and all captures, even if they do not lead to anything conclusive - some could be used as in-between moves. 3) King Safety

That alone is enough to avoid blunders.

These are the first three steps of the Karpov Method.
> 0 votes

---
Tags: psychology, blunder, best-practice
---


title: Syzygy tablebases in xboard

text:
# Question
Title: Syzygy tablebases in xboard
I'm trying to set up the five-men syzygy tablebases for use in xboard 4.8. Stockfish 6 and Komodo 9 are both supposed to support Syzygy, but in Xboard, their SyzygyPath option is missing from the UCI options.

I've tried setting up the tablebase through the GUI options but there's no documentation on how to do this with Syzygy rather than Nalimov that I can find. Anyone have a clue how this is done?

# Answer
> 3 votes
xboard is not a UCI user interface, so you'll need to install the Polyglot adapter to make it work. Once you have the Polyglot installed, you'll need to edit the polyglot.ini file. Read here for instructions on how to do it.

Please note Polyglot is not a very professionally made software. You'll only be able to find some old documentation. The whole process is quite technical. If you don't want to spend the time, you might as well consider other user-interfaces.

# Answer
> 0 votes
You can prefix the path with "syzygy:" (without quotes), at least, if there is only one path and you don't care about any other table type.

---
Tags: stockfish, tablebases, uci, winboard
---


# Question
Title: Algebraic to coordinate notation converter
I am building a chess board where I have one LED for each column and row, so I can represent moves by iluminating the orogin coordinate (e2) and the destination coordinate (e4)

However chess algebraic notation is simplified and the origin and destination coordinates need additional info to be calculated (like the board and the rules for each piece)

I am looking for some library or function that does this convertion (any language is fine).

Basically I need this function to translate my board coordinates to a chess engine notation and viceversa.

# Answer
> 4 votes
Java: https://github.com/bhlangonijr/chesslib/tree/master/src/main/java/com/github/bhlangonijr/chesslib

C++: https://github.com/alexmdc/chesslib

Python: https://pypi.org/project/python-chess/

C: https://sourceforge.net/projects/sankit/

These are all able to return long algebraic notation. Stockfish is reported to also.

# Answer
> 3 votes
> https://github.com/niklasf/python-chess

```
Parses and creates SAN representation of moves.

>>> board = chess.Board()
>>> board.san(chess.Move(chess.E2, chess.E4))
'e4'
>>> board.parse_san('Nf3')
Move.from_uci('g1f3')
>>> board.variation_san([chess.Move.from_uci(m) for m in ["e2e4", "e7e5", "g1f3"]])
'1. e4 e5 2. Nf3'

```

Do you see "g1f3" translates to `Nf3`?

---
Tags: computer-chess, notation
---


# Question
Title: What is the CQL syntax for combinations where king is checked along a file, and the square near it is attacked by bishop or queen?
I am looking to search for combinations similar to the one in Karpov - Taimanov, 1977 \- a knight check, is followed by opening of an 'h' file, and the rook comes with decisive effect because attacker's queen covers the diagonal. I am only learning CQL and any tips on how to get started on constructing a query would be much appreciated -

```
[Event "October Revolution 60th Anniversary"]
[Site "Leningrad URS"]
[Date "1977.06.25"]
[EventDate "1977.??.??"]
[Round "1"]
[Result "0-1"]
[White "Anatoly Karpov"]
[Black "Mark Taimanov"]
[ECO "B32"]
[WhiteElo "?"]
[BlackElo "?"]
[PlyCount "76"]
[FEN " "]

1. e4 c5 2. Nf3 Nc6 3. d4 cxd4 4. Nxd4 a6 5. c4 e5 6. Nb3 Nf6
7. Nc3 Bb4 8. f3 O-O 9. Be3 d6 10. Rc1 b6 11. Bd3 Bc5 12. Qd2
Be6 13. Nxc5 bxc5 14. O-O Nd4 15. Nd5 Nd7 16. f4 Rb8 17. f5
Bxd5 18. cxd5 Qb6 19. Rf2 f6 20. Rc4 a5 21. Ra4 Ra8 22. Qe1
Ra7 23. b3 Rfa8 24. Rb2 Qc7 25. Bd2 Nb6 26. Rxa5 c4 27. Bf1
Rxa5 28. Bxa5 Qc5 29. Bxb6 Qxb6 30. Kh1 cxb3 31. axb3 g6
32. fxg6 hxg6 33. b4 Kg7 34. b5 f5 35. exf5 Nxf5 36. Rb3 Qd4
37. b6 Ra1 38. Rb1 Ng3+ {analysis: 39. hxg3 Ra8} 0-1

```

# Answer
I'm still working out the full answer, but this is a start:

```
flipcolor {
    wtm check ng3 Pg2 Ph2 Kh1 r attack (q g1) not {
        square $x in h3-8 a on $x
    }
    result 0-1
}

```

This gets down to 13 games from over 2 million and includes the Karpov - Taimanov game. I still haven't figured out a way to deal with the rook, but this gets a game list small enough to look through. The not square bits could be taken out to expand the search to a couple of hundred games, that was just looking for the h file to not be blocked by black pieces for the later rook move.

I used the above in the latest Scid vs. PC codebase, which has CQL support by adding `cql()` to the beginning and running it in the CQL search vs. what is ChessBase Big Database 2017 updated last month.
> 3 votes

---
Tags: tactics, cql
---


title: Algorithms to score chess moves

text:
# Question
Title: Algorithms to score chess moves
How to score a chess move, which techniques are used to figure out how good a move is?

# Answer
> 1 votes
Firstly, I would like to point out, you cannot figure out how **good** is the move, because no move can improve position, only make it worse. And the winner is usually the one who managed to "destroy" his position less than the opponent. So the questions should be: "how **bad** a move is"... =)

Secondly, I believe you cannot actually `score` a move. You can only score the original position and the resulting position and subtract the former from the latter to find out how worse it became.

The position evaluation is quite big and complicated topic by itself. There are two ways -- static evaluation, when you just add up all pieces and some extra points for open lines, centered pawns and other things considered to be "good", and dynamic evaluation, when you start building a move tree, as far as you could, statically evaluate positions after a few moves and use min/max to derive the evaluation for the current position.

If you are interested, there are quite a few open source chess engines, starting from 100 lines of code, written in C, C++, Python and other languages, so you may easily choose the one you like and see how it works, maybe change a few lines and see what happens.

# Answer
> 0 votes
Initially the score based on a piece square value, which tends to centralize the pieces and give a bonus for castling. Some elements can add additional bonuses--such as, a capture, a check, or other forcing move. This value is how moves are sorted to be used by the search function.

The search function plays moves until a certain value is reached; be it a certain depth, score, or elapsed time. The final position is normally a quiet one to get a more reliable evaluation. This final score is added up by such elements as material, pawn structure, king tropism, space...

By looking at computer chess codes, this was the standard algorithms used to calculate moves, but with the success of AlphaZero, there is more of what we call intuition used.

---
Tags: strategy, candidate-move
---


# Question
Title: How is average centipawn loss calculated when a mate is missed?
As far as I know, to calculate the average centipawn loss, we calculate S1 \- S0 for every move, where S1 is the evaluation (in centipawns) of the position before the move and S0 is the evaluation (in centipawns) of the position after the move.

Let's take this position as an example:

```
[Site "https://lichess.org/kuvnBssO"]
[Date "2018.07.20"]
[Round "-"]
[White "Kulkid"]
[Black "WaisKamal"]
[Result "0-1"]
[WhiteElo "2016"]
[BlackElo "2107"]
[Variant "Standard"]
[TimeControl "30+0"]
[ECO "D44"]
[Termination "Normal"]
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
[SeUp "1"]
[StartPly "67"]

1. d4 d5 2. c4 Nf6 3. Nc3 e6 4. Nf3 dxc4 5. e3 { D44 Queen's Gambit Declined: Vienna Variation, Quiet Variation } Be7 6. Bxc4 O-O 7. Bd3 Nbd7 8. O-O b6 9. Re1 Bb7 10. a3 Bxf3 11. b4 Bxd1 12. Rxd1 c5 13. Bb2 cxd4 14. exd4 Qc7 15. Ne2 Rac8 16. Rac1 Qb7 17. Rb1 Rc7 18. f3 Rfc8 19. Ng3 h6 20. Ne4 Nxe4 21. Bxe4 Qb8 22. Bd3 Bf6 23. Ba6 Rd8 24. Be2 b5 25. Kf2 a6 26. Bc1 Nf8 27. Be3 Rdd7 28. Rdc1 Rxc1 29. Rxc1 Qd8 30. Rd1 Bxd4 31. Bxd4 Rxd4 32. Rc1 Rd2 33. Re1 Ng6 34. Ke3 f5 35. Kf2 Nf4 36. Kg3 Nxe2+ 37. Kf2 Qd4+ 38. Kf1 Qg1# { Black wins by checkmate. } 0-1

```

The given position is a mate-in-one (Qd4#). I missed this mate, and instead played f5, resulting in a position with an evaluation of mate-in-6. How will my centipawn loss be calculated for this move?

# Answer
> 5 votes
I cannot vouch for every engine available, but the general approach is, the mate is evaluated to something close to 15-bit integer, 32765 centipawns, and you get minus 1000 centipawns for every move-to-mate (to make it reasonable for the engine to sacrifice the queen (~900 cp) to delay the mate).

In your particular case, the original evaluation was `327.65` pawns, the mate-in-6 became something like `327.65 - 10.00 * 6 = 267.65` -- the numbers are not exact, and different engines may use slightly different approaches, but this one is the most common, I believe.

# Answer
> 2 votes
When calculating average centipawn losses for a game, a program does not necessarily need to directly use the centipawn output from the engine. If it did, then if the engine evaluates mate as 32765 centipawns, missing a single mate in 1 could incur about the same centipawn penalty as *losing a queen every move for the entire game*. That's just too harsh, even for a game-losing mistake.

The engine itself will report how many moves until mate along with any evaluation score, and any program or website that calculates average centipawn loss can interpret this output as it likes.

Chess.com's computer analysis gives an "Avg. Diff" stat, which is the average pawn loss for the game - multiply this by 100 and you get average centipawn loss. I experimented with it a bit, and it appears that they've implemented a limit of 1000 centipawns as the most you can be considered to have lost in a single move for the purposes of calculating this stat. It will use this 1000 centipawn value in missed mate situations, including in your situation where you played a move that mates in 6 moves instead of 1.

In my opinion, 1000 centipawns is a good limit to prevent the average from being skewed too much by one move, although personally I still wouldn't give such a harsh penalty to imprecisions in a game that remains won or lost for the same side. A move that allows you to mate your opponent in 6 moves instead of 5 should not be the same as a move that misses the win altogether. If I were writing the program, such inaccuracies would be maybe 100 centipawns instead of 1000.

---
Tags: evaluation
---


title: Doubt about defending piece

text:
# Question
Title: Doubt about defending piece
I just played a chess ga,e whose link is: https://lichess.org/mn8mcGT7/white#15 And I reached this position after the seventh move of Black.

I want to know why it is wrong to defend the piece with the bishop and is the right thing to do that with the white queen.

# Answer
You should always be skeptical about the "inaccuracy" annotations you get from Lichess (or similar sites) because it runs an extremely quick analysis; the small differences in evaluation that get called inaccuracies may go away when you let the engine run deeper. (Blunder annotations, on the other hand, are much more likely to be meaningful.)

While the engine initially liked Qc2 best, after letting the analysis of your position run to "completion" (depth 25) with 5 lines, the situation changes. Your results may vary because it's not even completely deterministic, but here's what I got:

As you can see, the "best" move now is to castle! But the first four moves are practically tied, between +0.7 and +0.6, and the two moves you mentioned, Qc2 vs Bd2 are now both at +0.6. At some points while the analysis was running, Bd2 was actually ahead. And I'm sure if you let it run longer (there's the "infinite analysis" option for that), they may trade places yet again.

In practice, they are both good moves as far as the engine can tell you, so you have to decide based on human factors or personal preference. For example, castling looks like it might lead to losing a pawn. Stockfish doesn't mind it, maybe because it can "see" the compensation (or how to recover it several moves later), but you might not be comfortable risking it.
> 5 votes

---
Tags: analysis
---


# Question
Title: QGD :: should Black fiancheto his King's Bishop?
A common line in the orthodox line of the QGD goes something like this:

```

[FEN ""]
1. d4 d5 2. c4 e6 3. Nf3 Nf6 4. Nc3

```

Here's the part that puzzles me. According to the database in 365chess Black's most common response in 4...Be7 presumably to support the knight in case of 5.Bg5 (which remarkably according to the same database is White's most common move even though after 4...Be7 no tempo is won). Anyhow, why doesn't Black simply play 4...g6 instead so he can conveniently fianchetto the King's bishop in response to 5.Bg5 ? This move does appear in the aforementioned database but way, way low. Why doesn't Black try to occupy the long diagonal with his King's bishop? Is there any strategic reason for Black in QGD for the King's bishop to remain on the a3-f8 diagonal instead?

# Answer
The main reason why Black tends not to fianchetto in this position is because she has already played `...e6`, which in conjunction with playing `...g6` to develop the bishop, unnecessarily weakens the dark squares on the black kingside without gaining anything; instead `...e6` has wasted a tempo that could otherwise be saved, and potentially hindered development of the other bishop. In other words, if Black is about to spend a move playing `...g6` to develop the kingside, it is better to wait on spending a move on the e-pawn.

Now it's true that, having played `1...d5` to start, the move `...e6` serves a purpose of reinforcing the pawn on d5. But this comes at the costs described above. That's why, if Black wants to fianchetto, she instead usually avoids an immediate `1...d5` and opts for things like the Gruenfeld or the King's Indian, moving straight ahead with that scheme of development, and pushing one way or another in the center after other things are clearer.

Consider a mainline King's Indian:

```

    [FEN ""]

1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 O-O 6.Be2 e5

```

Note that Black has here gotten in `...e5` in one fell swoop. And in a Gruenfeld, `1.d4 Nf6 2.c4 g6 3.Nc3 d5`, Black has played `...d5` but intends to get away without a reinforcing `...e6` move, instead playing for piece play against White's center.
> 4 votes

# Answer
4...g6 just gives you a bad version of a Grunfeld where Black has played the pointless weakening move ...e6, blocking in the light squared bishop.

It doesn't fit with Black's strategy in the QGD, which is to hold onto d5 with ...e6, exchange pieces, and carefully neutralize white's opening advantage. The kingside fianchetto belongs to the alternate strategy of allowing white to occupy the centre and then trying to obtain immediate counterplay by attacking it on the dark squares with Bg7 and ...c5 or ...e5, as in the Grunfeld and King's Indian.

Both approaches are viable, but work best when you commit to one or the other, rather than trying to mix them by playing ...e6 and ...g6.
> 2 votes

---
Tags: opening, theory, queens-gambit, fianchetto
---


# Question
Title: Moving a pawn to attack a piece on the 5th or 4th rank
I have not been able to tell why my computer sometimes tell me that advancing a pawn from its original square in order to kick an opponent piece is right and other times wrong. Take for instance, this game whose link is in case someone needs it: https://lichess.org/JdqqGV0Aekw4

In this case it is Ok to play a6 to kick out the knight. However, in this position: I played the obvious Nf3. However, it seems that kicking out the bishop with a3 would be a great mistake. I feel that sometimes kicking out these annoying pieces gets me in a less superior position whereas other times it is best kicking them out before castling or proceeding with the development of pieces and that is something that really confuses me. I would appreciate if someone could really give some kind of rule of thumb or at least some things to consider before doing those pawns advances.

# Answer
`Nf3` protects the pawn on `d4`, which otherwise will be taken by queen during the next move.
> 2 votes

# Answer
In the second example, after a2-a3, black does not have to retreat his dark squared bishop but can instead play ...Qxd4 when after axb4 Black can follow up with Qxd3.
> 5 votes

---
Tags: analysis
---


title: 15x15 squared board

text:
# Question
Title: 15x15 squared board
My brother and I made this 15 by 15 squares chess board that uses two sets of pieces minus a pawn and king for each color.

We have already played a game and find it extremely fun and interesting, but a lot to manage in our heads as there are so many options.

We decided that we might need to change some of the rules - like how pieces move or how they are initially set up. Right now we have each side set up as following.

```
P P P P P P P P P P P P P P P
R N B R N B Q K Q B N R B N R

```

We figured this provided a fair amount of protection, but is there a better layout? For instance, should queens be on one side of the king?

Queens remain very powerful, but bishops massively increase in power compared to the other pieces since they can cover so much distance. Rooks are difficult to move out as usual which is fine, but knights and pawns are pretty hard to get into the middle game.

We had a few ideas to fix this issue. We thought we will have pawns be able to move either 1, 2, *or 3* spaces on their first turn. We are also considering giving knights a larger ‘L’ shape (not sure exactly what shape - suggestions welcome).

And then there is castling to figure out. We had an idea to give the king the ability to either castle with the nearest rook when he can under usual conditions when no pieces are blocking... or with the furthest rook if he can under usual conditions when no pieces are blocking.

I’m asking for advice on set up and rules that maximize fun gameplay and strategy. Any creative suggestions are welcome, but I’m also looking for some real logic to back up most ideas. Try to notice potential flaws with having a giant board and how to fix them by modifying set up and rules.

# Answer
> 4 votes
A fun rule could be to allow the King to castle two times:

1. First in the standard way in the standard array
2. Second with the corner rook in the same direction

For the second castling, the restriction is the usual one except for the King who has made no other move than the first castling.

# Answer
> 3 votes
I agree that giving the knights and pawns extra movement power to compensate for their current short range.

As the board is (almost) doubled, the pawn movement ability should also be doubled. Allow them to move either 1 or 2 squares and, in addition, 3 or 4 on their respective first move. The rules for en passant would have to be adjusted.

The knight is trickier. I think that the knight always changing color squares should be adhered, so the natural additions would be a 3x2 or a 4x3 pattern.\[1\] The latter allows for the natural king-rook fork while the other allows the queen-rook fork. They both seem to allow too many forks due to the extreme power given to the knights.

\[1\] As the correct movement of the knight is described as 1 square forward and one square in the same direction diagonally, The suggested move would be the same but allowing 2 or 3 squares diagonally, respectfully.

---
Tags: strategy, rules, chess-variants
---


# Question
Title: What's the point of the full move counter in FEN?
For what do you need to know the number of full moves? You still can't recreate every move in the game with FEN anyways, so I don't see the point of the full move counter. Is there any rule that depends on it?

# Answer
You may want to record a fragment of a real game starting from move number 24, for example. Then you specify the FEN after the first 23 moves and set the full move number to 24.
> 11 votes

# Answer
One rule that depends on the move count is the time control. If you have a time control of 40/120, you need to know which move it is to know when the players get more time.
> 4 votes

---
Tags: fen
---


title: Is this knight sacrifice a good idea?

text:
# Question
Title: Is this knight sacrifice a good idea?
I often play the following variation with black when I play blitz. Somehow it refuses the known lines of the Spanish.
It looks like that black is going to be destroyed but almost always I win when I play this opening.

```
[FEN ""]

1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O b5 6.Bb3 Be7 7.Re1 O-O 8.c3 Nxe4!?

```

The main idea is that IF white accepts the sacrifice, he/she is going to suffer a pawn storm who will paralyze the queen side.
Almost always (I mean over 95% of the times) the game continuous like this:

```
  [FEN ""]

1.e4 e5 2.Nf3 Nc6 3.Bb5 a6 4.Ba4 Nf6 5.O-O b5 6.Bb3 Be7 7.Re1 O-O 8.c3 Nxe4!? 9.Rxe4 d5 10.Re1 e4 11.Nd4 Ne5

```

And after this continuation, black has strong attack.
I really liked the idea that I found something *different* to play when I am facing the Spanish (By the way, is 8... Nxe4 a "new" idea?), but I think it is possible to get crushed in a game which is not blitz.
So my question is:

> Is 8...Nxe4 a move which gives black something good in general?

# Answer
The sacrifice is quite dubious. Besides the answers with 10.Nxe5, 10. Rxe5 is simply two knights for a rook and there is no attack for Black.
> 8 votes

# Answer
This is really a question for the engines, but it's hard to believe that Black has enough compensation here for his creatively sacrificed material. White could also return a fraction of the material with

```
10 Nxe5!? dxe4 11 Nxc6 Qd6 12 Nxe7+ Qxe7 13 d4

```

and be just up B+N for R; or return a bit more material in your main line with 12 Qh5 followed by 13 Nc6!? which seems to end up with White having an extra pawn, which is a bigger advantage than White normally gets from this opening.
> 5 votes

# Answer
As other already pointed out, black doesn't have enough compensation and white can even give back some material to have an easy game.

But even in the last line where you keep the material and black plays Ne5, you can play d3 to free yourself up, and black cant really capture that pawn, at least not right away due to:

```
[FEN "r1bq1rk1/2p1bppp/p7/1p1pn3/3Np3/1BP5/PP1P1PPP/RNBQR1K1 w - - 2 12"]

1. d3 (1... exd3 2. Rxe5) Nxd3 2. Nc6 Qd6 3. Nxe7+ Qxe7 4. Qxd3

```
> 3 votes

# Answer
I think black is totally lost here, after d5, Nxe5 seems to be winning easily for white.

Even in your position, after f4 and Nc6 and taking on e7, white seems to be up a piece for no compensation.
> 1 votes

---
Tags: opening, ruy-lopez, sacrifice, opening-traps
---


# Question
Title: Studies on how people really improve at chess?
How do people ***really*** improve at chess?

I often hear people say that any of the following will improve a player's ability:

1. Doing tactics puzzles
2. Playing more games
3. Playing bullet games
4. Playing longer games
5. Playing correspondence games
6. Memorizing openings
7. Analyzing own games
8. Reading chess books

Sometimes I hear a specific example like "I've been doing tactics puzzles since last year and it has improved my understanding significantly", and then I ask for their lichess name, and I check it, and their rating has been extremely steady for the last 3 years.

Often these kinds of suggestions seem at first to be anecdotal, but even anecdotes would be true. These are worse than anecdotes because they are not based in reality.

Is there some scientific study of GMs and their history to find out exactly the key points that made them great? Or some study of kids over time with different training techniques and comparison of rating changes to see what works and what doesn't?

As far as I can tell, the thing GMs have in common is that they all had strong chess coaches when they were kids and became very strong players by the time they were 15 or younger.

# Answer
> 4 votes
The closest thing there is to a long term study from child to gm of training techniques would be the polgar sisters. I'd advise searching for information on them to answer your question. Also I'm sure old soviet literature is full of ways to train chess GMs, they specialized in that for many years and had quite a few methods they thought optimally trained young players.

Anecdotally I can tell you from 2000 to 2200 I trained 2 hr 45 minutes on average each day, studying at minimum 10 chess tempo tactics, 3 recent gm games, a gm game of guess the move on chesstempo, and 1 15+ minute game on ICC a day with about an hour spent afterwards studying related games and opening lines. I also participated in an endgame club for about 4 months that year, read through Dvoretskys Endgame Manual, and Endgame Strategy by Mikhail Shereshevsky. At the beginning of that year (first 3 months) I also read through Winning Chess Middlegames by Ivan Sokolov.

For the first 10 months I gained maybe 50 rating points over 3 tournaments. I gained 150 points in 2 tournaments in the last two months.

I think this level of training could probably net 400 points in a year at lower levels, so long as young trainees were given optimum resources to practice with. Often times people use books that are either not suited to their level, don't address their weaknesses, or simple aren't very good. Also people have a tendency to play a lot of blitz or do things they find easy, but not the optimal things for improving their strength.

/end anecdote

---
Tags: learning
---


# Question
Title: What happened with the Fide online areana?
About a year ago I stumbled on arena.myfide.net which looked promising , and unique in the ability to get an actual Fide rating. But in that year no progress has been made with the site, and mobile support continues to say "coming soon". Is this site dead? Or are they just really taking their time with it?

# Answer
It is active and the mobile/tablet option is still coming.

Fide Rated tourneys are daily for various time controls.
> 1 votes

# Answer
The website is working. You need to download the latest java version on your computer. The arena is an excellent platform to practice. I don’t think any titles can be bought. You have to work hard to get to the AGM level as well.
> 0 votes

---
Tags: online-chess
---


# Question
Title: Evaluation of this alternative to French exchange lines
I am a French Defense opening player from both sides. I don't like exchange line of the French Defense. They are drawish positions and my brain gets bored resulting in a positional or small mistake.

I have never played it at a 90+30 FIDE rated games, and I know the engine says this is not good at all. Anyhow I have played c5 with black several times on blitz, and I still do it.

The level of the players I play against rounds the range 1650-1900. There are some tricks if white don't plays well. Sometimes, especially for the players with lower rating. d4 or d5 pawns get pinned and become a trouble.

Should I stop playing it?

```
rnbqkbnr/pp3ppp/4p3/2pP4/3P4/8/PPP2PPP/RNBQKBNR w KQkq c6 0 4

```

I think I should have played this following line some dozens of times, having good results with black at blitz at a level 1650-1800.

```
[FEN ""]
[Date "2018.07.29"]
[Round "-"]
[White "?"]
[Black "?"]
[Result "*"]

1. e4 e6 2. d4 d5 3. exd5 c5 4. dxe6 Bxe6 5. Bb5+ Nc6 6. Nf3 Qa5+ 7. Nc3 O-O-O *

```

Less frequent, but sometimes they fall, I recover the pawn, and there is misdevelopment. eg:

```
[FEN ""]
[Date "2018.07.29"]
[Round "-"]
[White "?"]
[Black "?"]
[Result "*"]

1. e4 e6 2. d4 d5 3. exd5 c5 4. dxc5 Bxc5 5. dxe6 Bxf2+ 6. Ke2 Qxd1+ 7. Kxd1
Bxe6 *

```

At some of the games I played -note it is blitz- they have clear they wanted an exchange and they just do not try to profit white's advantages. Then I like to have my pawn at c5 and accept the exchange and avoid the gambit variation.

```
[FEN ""]
[Date "2018.07.29"]
[Round "-"]
[White "?"]
[Black "?"]
[Result "*"]

1. e4 e6 2. d4 d5 3. exd5 c5 4. Nf3 exd5 *

```

# Answer
> 3 votes
This gambit looks extremely dubious since you give a central pawn, White has played only developing moves and she has no weakness.

Besides the unassuming 4.Nf3, insisting on an exchange French, you could be worried about:

* 4.Nc3, transposing into the rare Marshall French (3.Nc3 c5?! 4.ed5). It is considered to favour White. The very slight plus side for you is that since White has played 3.ed5, he might not be too familiar with this line.
* 4.c4, when after 4...ed5 the very open position means that the extra tempo will probably be valuable.
* 4.de6, grabing the pawn in exchange for a single developing tempo. After 4...Be6 5.Nf3 there is no doubt that Black's compensation is unsufficient.
* 4.Bb5+, probably the most critical, accepting the challenge. After 4...Bd7, any of 5.Nc3, 5.a4 a6?! 6.Bc4 and 5.Qe2 make sense.

All in all, you can use this line in online blitz in you like to (but I wouldn't). However I consider it totally unsuitable for 'serious' chess with rapid or classical time controls.

# Answer
> 2 votes
I don't see the point of saccing a pawn for no reason. The exchange french can lead to sharp positions, in fact as white I play exchange french when trying to win as well. Perhaps you need to study the opening a bit more before jumping to conclusions.

I would castle long, and pawn race on opposite sides of the board.

# Answer
> 2 votes
My initial reaction is that as white I'm going to play Bb5+ followed by de and ef+ if you let me. I might even be prepared to sacrifice the bishop on b5. Your king is going to be very exposed.

---
Tags: opening, gambits, french-defense
---


# Question
Title: What is the best strategy for simultaneous blindfold chess?
Recently, Timur Gareyev displayed tremendous prowness by playing many boards blindfolded. What is the best strategy to visualize each and every board? I already know the basics, like splitting the board into 4 parts, adopting different techniques for each stage of the game (opening, middlegame, and endgame), trying to visualize the board, and recognizing patterns or ideas.

How do I scale it up for many boards?

# Answer
This question involves the human mind's memory, so to start, let's play a quick game. Look at the line below for 1 second, and then look away immediately.

G R T A O H V I L P

Now try to recall as many of the letters as you can.

Now do the same thing for the next line (look for 1 second):

Fish Table Plate Water Mouse Cookie Scroll Piece Fan Ball

Recall as many of the words as you can.

---

The number of letters you were able to remember is probably close to the number of words you remembered. This is because human minds chunk many small things into bigger things, if given the opportunity. Words are just letters being chunked together. Note though, that if you didn't know what "Cookie" is, chances are you wouldn't have remembered it (since your mind wouldn't have had the opportunity to chunk C,O,O,K,I,E into one word).

This process can be applied to chess positions. You want to give your mind more opportunities to chunk pieces ("letters") into positions you can memorize ("words"). The key to doing this is pattern recognition; training your mind to immediately recognize positions (or immediately chunk certain arrangements of pieces together). Pattern recognition is just like learning new words in a language.

The best way to improve pattern recognition abilities is to look at many chess positions, over and over and over. Solving puzzles is a great way to do this since your mind is actively thinking about positions, allowing them to be stored and accessed easier from long-term memory. This not only helps your chess playing abilities, but also how well you can hold many positions in your head. If you can immediately see arrangements of pieces and know that they're a certain position (like C,O,O,K,I,E means "cookie"), then all you're really doing is holding big words in memory.
> 4 votes

---
Tags: chess-variants, simultaneous, blindfold-chess
---


# Question
Title: How did Taimanov lose this game to Karpov?
I can't understand how Taimanov (playing White) resigned in the following position against Karpov from the Moscow team leagues in 1973:

After 40.Rc2 or 40.d5 the position seems to be equal. I know Taimanov was notorious for getting into time trouble. Did he just forfeit on time?

# Answer
> 9 votes
In the book "How Karpov Wins" by Edmar Mednis it is stated on page 174 that "White overstepped the time limit and lost". The book seems to be fully available on Google books and has a lot more analysis of the match.

https://books.google.com.au/books?id=x8MV0uoAJp0C

---
Tags: history
---


# Question
Title: What are the most instructive Zurich 1953 games?
I'm a club player that never really figured out the importance of studying master games. Since I want to improve my middlegame understanding I read that Bronstein's Zurich 1953 is an excellent place to start. However, going through the games takes 1-2 hours/each and I was wondering if some games illustrate the key concepts better than the other.

# Answer
There are of course classics like the Averbakh-Kotov game.

But generally you get out of chess study, what you put into chess study. So you should play through games that interest and fascinate you. It should be fun, not something were you try to minimise the time spent from the outset.

For me, that meant for a long time wild tactical games. I played for example through the games in Bronstein's "Sorcerer's Apprentice", Tal's "My Life and Games", Christiansen's "Storming the Barricades" and Aagaard's "Attacking Manual".

I do own Zürich '53, but I don't think I ever spent much time on it.

But if you already own the book and want to proceed, I would recommend restricting yourself to well annotated, decisive games that feature openings from your repertoire.
> 1 votes

---
Tags: middlegame, master-games
---


title: Strange reply after winning game

text:
# Question
Title: Strange reply after winning game
So I was playing chess at ICC where I am a member. I lost the game and I usually like to offer congratulations and a handshake to the winner. So on this occasion I said handshake and she, the other player, replied, foot shake.Isn't this a strange reply or was it just a joke of some kind that I didn't fully grasp ?

# Answer
> 4 votes
Consider it being a joke and move on. There's a lot of strange people on chess servers, there's people who speaks poor English, there's people who tend to harass or offend other players for their amusement...

If you come to the chess server to play, ignore the comments from others and just play. There's no point talking to strangers, unless they offer a sound advice of some kind (that's pretty rare occasion).

Once done with the game, say "thank you" or anything you like and move on. Life's too short to spend time pondering on meaningless comments.

---
Tags: online-chess
---


# Question
Title: Analysis of my recent King's Indian Defense game
I'm looking for any feedback on positional ideas I've missed on a recent KID game I played (as black). We were both about 1900 Elo, although I was slightly higher rated. I've obviously already analyzed it with an engine, pointing out a few of my missed tactical shots in the game in these annotations. But this was a very complicated game, so I would like any and all feedback on better lines and/or positional ideas for either side.

```
[FEN " "]
1. c4 Nf6 2. Nc3 g6 3. e4 d6 4. Be2 Bg7 5. d4 O-O 6. Rb1 a5 { Trying to shut down the obvious b4 plan by white. The more natural c5 is slightly better, but I had already decided on going for a classical KID with an e5 break. } 7. Nf3 e5 8. Bg5 (8. dxe5 dxe5 9. Qxd8 Rxd8 10. Nxe5 Nxe4 11. Nxe4 Bxe5 $17) 8... Nc6? { Mistakenly assuming that white's only play was d5, and completely missing that this move loses an exchange. } (8... h6 {The move I'll play next time I see this position. } 9. Be3 (9. Bh4 g5) 9... Ng4 10. Bc1) 9. dxe5 dxe5 10. Qxd8 Rxd8 11. Rc1? { This mistake fails to capitalize on my poor play. } (11. Nd5 Nxd5 12. cxd5 f6 13. dxc6 fxg5 14. Nxg5 bxc6 { Engine-like best play temporarily holds on to all material but completely ruins all chances of black fighting for a win. }) 11... h6 12. Be3 Ng4 (12... Nd4!? 13. Nxe5 Nxe2 14. Kxe2 Nxe4 15. Nxe4 Bxe5 { Wins the two bishops and retains active pieces. }) 13. Bd2 Be6?! (13... Nb4!? 14. a3 Na6 { This maneuver keys in on the weak c5 square. But making repeated knight moves means the queenside development is lacking. }) 14. O-O Nd4!? { Acquiring a passed pawn almost by force. The knight lands on a beautiful square and cannot be kicked away. } 15. Nxd4 exd4 16. Nb5 Rd7?! {An awkward move - I thought I was better here, but my opponent comes at me with a lot of pressure.} (16... Rac8?! 17. Bxa5 d3! 18. Bxg4 Bxg4 19. f3 Be6 20. b3 Rd7 { I'm unconvinced by the computer line which makes no sense to me. }) 17. f4!! { An extremely strong reply and a move I had completely missed. With f5 coming, the knight can be left stranded on g4 in many lines. } 17... f5!? { Gives white a passed pawn with e5, but I figured black's would be stronger. } (17... c6 18. f5)  (17... Re8 18. f5 Bxf5 { The computer move to stop f5. }) 18. c5!? { A very interesting pawn sacrifice that turns the knight (and eventually c1 rook) into incredibly active pieces. } (18. exf5 Bxf5 19. c5) 18... fxe4 19. c6! bxc6 20. Rxc6 d3!! { There's no time to cower from each other's threats. Black is pushing through in the center and white is crashing through on the queenside. } 21. Bd1 Bf5? { Immediately after deciding that I had to play actively, I falter with a slow move. I needed to keep up the active play with the brilliant Bd5! } (21... Bd5!! 22. Bxg4 (22. Rxc7 Rxc7 23. Nxc7 Bd4+ 24. Kh1 Nf2+ 25. Rxf2 Bxa2!!)  (22. Rxg6 Nf6 23. Nc3 Kh7 24. f5 Bf7 25. Rg3) 22... Bxc6 23. Bxd7 Bxd7) 22. h3 Nf6 23. b4?? { I truly have no idea why this move was played. } 23... axb4 24. g4 Rb8!? { Attack - counterattack. } (24... Rxa2?? 25. Bb3+) 25. Nxc7 Rc8 26. gxf5 Rdxc7 (26... gxf5 27. Bb3+ Kh7 28. Rfc1 {The reason you have to immediately take the pinned knight.}) 27. Bb3+ (27. Ra6 gxf5 28. Bb3+ Kh7) 27... Kh7 28. Ra6? (28. fxg6+ Kxg6 29. f5+ Kh7 { The line I expected. Does the bishop pair and active rook make up for black's 2 passed pawns? }) 28... gxf5 29. Kf2?? { An interesting idea - allowing the king to become a blockader and the rook to use the open g file. But it's ultimately way too slow. White is down 2 pawns and must show compensation. } (29. Be6 Re8 30. Bxf5+ Kh8 31. Bxb4 { The line I expected. While material is balanced, I felt that black's two central pawns should rule the day. }) 29... Rc6 30. Rxc6 (30. Ra7 R8c7 31. Rxc7 Rxc7 32. Be6 Rc2 33. Bxf5+ Kh8 { I was sure I had enough to win in this line. }) 30... Rxc6 31. Be3 Bf8! { Trading bishops and ensuring that black's king can rely upon the dark squares. } 32. Rd1 (32. Bd4 Bc5 33. Ke3 Bxd4+ 34. Kxd4 Nh5 35. Ke3 Rg6 { An interesting sideline I was trying to evaluate. }) 32... Bc5 33. Rg1 Bxe3+ 34. Kxe3 Rd6!! { Giving up the open file, but preparing Nd5+ after which the game is immediately decided. } 35. Rg2 (35. Rc1 Nd5+ 36. Bxd5 Rxd5 37. Rc4 d2) 35... Nd5+ 36. Bxd5 Rxd5 37. Rg1 d2 { Simplification. From this move onwards, I saw to the end. } 38. Ke2 d1=Q+ 39. Rxd1 Rxd1 40. Kxd1 Kg6 41. Kc2 Kh5 42. Kb3 e3! { And the white king must return to stop the queening e pawn. } 43. Kc2 Kh4 44. Kd3 Kxh3 45. Kxe3 Kg3 {White surrenders.} *

```

In particular, I'm curious about what people think about:

* 14... Nd4 - is it too premature to start thinking about passed pawns as soon as the queens are off?
* 16... Rd7 - this awkward move was very hard to make. Is black just worse here, even with the passed pawn?
* 18. c5 - sacrificing a pawn, but drumming up a lot of counterplay on the queenside. I felt that this move was a blunder during the game, but the pressure I came under seems to prove that it was not.
* 23. b4 - What's the point of this move?
* 29. Be6 - Is my assessment of this sideline accurate? Does black have enough to win?

Looking forward to your analysis! Hopefully others find this game instructive; I certainly learned a lot playing (and subsequently analyzing) this middlegame.

# Answer
> 2 votes
> 14... Nd4 - is it too premature to start thinking about passed pawns ...?

...Nd4 is highly desirable for a number of reasons! Besides the fact that White is inclined to capture an give you a passed pawn, you get more space, extend your dark square bishop and free your c-pawn to cover the d5 hole.

> 16... Rd7 - this awkward move was very hard to make. Is black just worse here?

Nothing wrong with Rd7 that I can see.

> c5 - sacrificing a pawn, but drumming up a lot of counterplay on the queenside. I felt that this move was a blunder during the game, but the pressure I came under seems to prove that it was not.

18.c5?? a terrible blunder! White gives you connected passers in the middle of the board for what -- a chance to get back the crappy pawn on c7? This is the losing move in my opinion.

Besides those questions let me comment: I don't agree with a lot of your annotations for example, why is 17.f4 a double exclam? At best it is !? of course after 17...f5 (which is standard) White should have played 18.e5

I do agree 13...Be6?! is poor, but favor 13...f5 over your suggested Nb4.

# Answer
> 1 votes
14...Nd4: it's never too early to think about passed pawns.

16...Rd7: I think black is fine here, but I would consider Nf6 with a counterattack on e4 or d3.

18. c5: I would consider e5, shutting down the B-g7, or Bxg4 to win a tempo and play c5 next move.
19. b4: This is a question for your opponent. I prefer a4, fixing the weakness on a5, or Bb3+, controlling d5 and allowing the other rook to enter the game.
20. Be6: The assessment is correct as 32... Nd5 wins outright.

In the first variation, 10. Nxe5 is incorrect. Better is 10. Bg5 with the threat of Nd5.

I've suggested this before: post the game on lichess.org. It's free to join, the analyses will be better, and this forum isn't really meant for this type of question.

Note: I'm only a 2000, so my superficial opinions may not be any better than yours.

# Answer
> 0 votes
It is a little awkward to comment while knowing that you have already checked the game with an engine, so you may be aware of tactical flaws in our suggestions, but does 23.g4!? wins material ?

Bf5 is trapped, and after 23...e3 24.Bb3 Kh8 25.Bxe3 Be4 26.Rxc7 seems to collect two pawns. 23...Rb8 is much less strong than in the game since 24.a4 (probably best), 24.Na3 and even 24.Nxc7 are available.

---
Tags: analysis, positional-play, middlegame, kings-indian
---


# Question
Title: Worst tournament performances of reigning World Champions
As a Magnus Carlsen fan, it was a bit disappointing for me to see him finish clear second in Biel 2018, one and half points after Mamedyarov, after starting the tournament with two wins - and it could have been two points - had not the much lower-rated Georgiadis blundered in a drawn endgame. Although not a bad performance *per se*, I was wondering what were the worst tournament performances of reigning World Champions?

# Answer
Looking through this list of strong tournaments, among those that stand out are:
> 8 votes

# Answer
For Carlsen that was probably Norway Chess 2017, where he finished second to last on -1.
> 7 votes

---
Tags: tournament, world-championship, carlsen
---


title: Why is it better to capture the f pawn?

text:
# Question
Title: Why is it better to capture the f pawn?
Yesterday I reached this position:

```
[fen "rnbqk1nr/ppp3bp/3pp1p1/5p2/2PPP3/2N2N2/PP3PPP/R1BQKB1R w - - 0 1"]

1. Bg5 (1. exf5)

```

White to play, I played Bg5.
Lichess told me in the analysis that was inaccurate although latter on, it pointed this move out as one of the best moves.
At first, he recommends me to move exf5 in the 6th move and in the next moves for White.
I would like to know why it is convenient to make this capture since I do not see any benefits in capturing this pawn at any time.
The link of the game is: https://lichess.org/PyqeZZnQ/white#10

# Answer
If the black captures in return (there's not much choice for black), you either get an open vertical `e` or a nasty attack on the black King by `Qh5+` and so on.

But don't worry. `Bg5` is also not so bad move =)
> 3 votes

# Answer
In general it is dubious to put too much faith computer evaluations of less than a pawn in determining the "best" move.

In this position however I think serious thinking is required. **Let's think like a human:** Black has made a lot of pawn moves and is therefore behind in development. In such cases it is usually good to open the position.

Okay that suggests exf5, Now you need to "think like a Grandmaster":

6.exf5 (a) 6...exf5 enumerate candidate moves: (a1)7.Nd5 (a2)7.Bg5, etc. Things get complicated but you can see ideas based on Nd5 combined with Qe2+ and Bg5 can lead to difficulties for Black.

(b) 6...gxf5 (b1)7.Ng5 Nf6 8.Qe2!? (b1.1) 8.Qa4+ (idea 9.Qb3)...

It seems 6.exf5 looks promising, now does 6.Bg5 look as good? Well the computer gives 6...Bf6?! 1.5 to White so that doesn't make 6.exf5 better; and it says after 6...Ne7 7.exf5 gxf5. Hmmmm, on 6.exf5 it liked 6...ef5 -- because now exf5 allows Nd5. So we can force gxf with Bg5... is that what we want?

```
[fen "rnbqk1nr/ppp3bp/3pp1p1/5p2/2PPP3/2N2N2/PP3PPP/R1BQKB1R w - - 0 1"]

1. exf5 (1. Bg5 Ne7 (1...Bf6?) 2.exf5 gxf5) gxf5 (1...exf5 2. Nd5) 2.Ng5 Nf6 3.Qe2!? (3.Qa4+ null 4.Qb3)

```

Looking at these positions which are you more comfortable playing? That is the practical question. 6.exf5 might be a fraction of a pawn better if you are a computer.
> 1 votes

---
Tags: analysis, pawns, captures
---


title: Autobiography by Sonja Graf

text:
# Question
Title: Autobiography by Sonja Graf
In the book "Chess Bitch" by Jennifer Shahade I have read that Sonja Graf has written an autobiography in Spanish. Can anyone help me locate the book? It could be in Spanish, German, English or Russian.

# Answer
> 7 votes
She wrote two autobiographical books while in Argentina: "Así juega una mujer", Buenos Aires 1941 and "Yo soy Susann", Buenos Aires 1946. Susanna was her real first name. Bibliographic data in WorldCat:

https://www.worldcat.org/title/asi-juega-una-mujer-impresiones-y-recuerdos-de-la-carrera-ajedrecistica-de-la-autora-y-psicologia-de-los-ajedrecistas/oclc/55440304

and

https://www.worldcat.org/title/yo-soy-susann-relato-intimo-y-autobiografico-impresiones-reales-recuerdos-y-confidencias-amorosas-historia-de-la-vida-en-si-misma-con-su-ensenanza-y-su-verdad/oclc/65716357

And this page contains photos of both books (scroll down): http://www.tabladeflandes.com/gabriel/gabriel-capo-16.html

---
Tags: books
---


# Question
Title: What is the correct definition of a bad bishop?
Is a bad bishop a bishop that is trapped by your own pawns? (For example, all your pawns are on dark squares, so the dark squared bishop is bad.) Or is it when your opponent's pawns trap your bishop's mobility? (For example, they control the dark squares which your bishop controls, so the bishop is bad).

# Answer
What you defined is an "inactive bishop". An inactive bishop can be a bad bishop, but they are technically two different situations.

A "bad bishop" is a bishop that is on the same color as it's own center pawns. An "inactive bishop" is one that is blocked by it's own pawns.
> 14 votes

# Answer
When evaluating a bishop, there are two totally separate things that must be considered. The first is whether a bishop is "good" or "bad". These are very much misnomers because they have nothing to do with the worth of the bishop. The second consideration is whether the bishop is "active" or "inactive". Finally, there may be mitigating factors as well (is the bishop doing something useful?).

# Good vs Bad

A **good** bishop is on the opposite color as its pawns. A **bad** bishop is on the same color as its pawns. For example if the white pawn structure is c3, d4, e3, f4, then the light squared bishop is the good bishop and the dark squared bishop is the bad bishop.

# Active vs Inactive

An **active** bishop is outside of the friendly pawn chain (in the above example, if the bishop is on e5, then it is clearly both active and bad). An **inactive** bishop is trapped by pawn chains - either the player's color or the opponent's.

# Mitigating Factors

There are two main mitigating factors. The first can be remembered by a common phrase: "bad bishops defend good pawns". This means that a bishop might be very bad (same color as all the friendly pawns) but if it is defending them from attack in the endgame, then it might be enough to hold a draw. Usually it is much harder to win with the bad bishop though.
The other main mitigating factor is if the bishop is defending its own passed pawn or stopping an enemy passed pawn.
> 19 votes

# Answer
Several useful answers were given here last year, answers which illuminate the exceptions to the rule so well that—when the answers are read together—they seem almost to leave the rule itself in shadow. Let me cast my flickering light therefore directly upon the rule.

**The good and the bad bishop**

The technical adjectives "good" and "bad" have much to do with the worth of a bishop. A good bishop very often wins a game of chess. Indeed, unless one has a material lead of two pawns or better, has a passed pawn, or can push or trade pawns to make a bad bishop better, to win an endgame with the bad bishop can be hard. On my own, limited experience, I should go further: I would say that to win with the bad bishop, without a strong counter-advantage to compensate so great a disadvantage, were seldom possible absent a gross enemy blunder.

**Good against bad bishops in the endgame**

Endgames that feature opposing bishops on squares of the same color are quite common in chess, as you undoubtedly know. As soon as such an endgame seems probable, one might consider pushing as many of one's pawns as possible, on both flanks, as fast as possible, to squares of the color the bishops cannot reach.

In class-D and class-C play, to have pushed pawns in so simple, innocuous-seeming a manner often wins the game 20 or so moves later; insofar as opponents at this level, not grasping the principle, have no idea why you would spend valuable late-middlegame time to push seemingly random pawns. One, quiet attraction of winning a game in this manner is that it leaves one's opponent with little notion as to why he has lost. (Indeed, I suspect that it is in large measure because of the mysterious bad-bishop principle that class-D players tend to dislike endgames, why some will launch unsound attacks just to avoid endgames. They repeatedly lose endgames for no visible reason and don't know why. All endgame maneuvering, all endgame calculation seems mysteriously futile to them. The unseen reason, of course, is that they have lost, or at best drawn, before the endgame ever began by letting opponents choose *during the middlegame* the color of the squares on which endgame pawns must stand. They think you and your bishop cleverly nimble, hardly realizing how easy it is to be nimble when one's bishop is good.)

**Other endgames involving bishops**

Endgames that feature opposing bishops on squares of different colors admittedly work on another principle, though such games are significantly less common in practical play. In bishop-against-knight endgames, which are common enough, however, the square-color principle again emerges, though in a less pure form.

**Why the good bishop is good**

The good bishop is good for three principal reasons:

1. because it guards and attacks squares its pawns do not cover;
2. because it is nimble; and
3. because its pawns can blockade, and thus fix, *opposing pawns on bad squares.*

The bad bishop does possess the counter-advantage that it and its pawns can guard one another but, except maybe when the pawn is a rook pawn, such a counter-advantage seldom compensates.

**Definitions and remarks**

Others have already answered your question about definitions well enough, so here I will add only that I have read the definition as given both with and without reference specifically to central pawns. When speaking of the opening, I should call a bishop technically bad when central pawns stood on squares of its color, without much reference to flank pawns, as others have noted. However, from the early middlegame, my view should gradually broaden toward the flanks, eventually taking all pawns into account of the bad bishop. The two definitions are not unrelated, of course, for the technically bad bishop of the opening is more likely to become the dispositively bad bishop of the endgame than is a technically good bishop, unless its owner either has taken steps to improve it or has swapped it off.

Consider establishing a good bishop when you can. It may win you some games otherwise drawn or lost.
> 6 votes

# Answer
A "bad" bishop is one that is not performing the normal function of a bishop. That is usually one behind its own pawns. The test is, "if I replaced the bishop with a pawn, would it make any difference?" If the answer is no, then it is a bad bishop.

A Bishop can be behind a wall of pawns and still be very useful. Say there is a bishop on g7 in front of its king on g8, and behind pawns on h6, g5, and f6. As the "linchpin" of the defensive system, the bishop is very useful, even though it has little mobility. (Unless this is a situation where all the action is on the queenside, in which case the bishop would really be "bad.")
> 4 votes

# Answer
The term itself is rather simple. A "Bad Bishop" is one that is on the same color as most/all ( the higher the percentage, the worse the bishop) **and is behind them**, that is to say, the pawns are preventing it from attacking the enemy.

If you can get your light-square bishop on the outside of your pawns, it's will no longer be bad, though it may have reduced mobility.

Defensive or not, a bad bishop is bad (the logical end of defensive warfare is surrender - Napoleon) and its bad because it does nothing to limit, or otherwise influence, the actions of the enemy.

Never willingly accept a bad bishop unless you get something in return.
> 4 votes

# Answer
A bad bishop is one where many of its own pawns are on the same color as it. This definition is very strict, and there's very little subjectivity involved.

An inactive bishop is one that lacks activity. This definition is much less strict, allowing some subjectivity.

As per your question, a bishop trapped by its own pawns would be both bad and inactive, while a bishop trapped by its own pawns would just be inactive (we need info on the color squares of its own pawns to say whether it's "good" or "bad").

It should be noted that a bishop can be "good" and "inactive". Good meaning its own pawns are on the other color complex as it, but inactive since it lacks activity (possibly due to the opponent's pawns blocking it in).
> 2 votes

# Answer
Every piece has a strength that depends on the position on the board. More specifically, it depends on the pawn structure and piece placement. As you correctly point out, a bishop trapped behind its own pawns (e.g. white has Bc1, pawns on b4, c3 and d2; black has pawns on b5, c4 and d3) is a bad bishop. In general, a bishop that has almost no available squares and/or no targets to attack is a bad bishop. For example, the rule of placing your pawns on squares that are of the opposite color to the squares that the bishop controls is related to both of these factors. If you have a dark squared bishop and you place your pawns on light squares, two things occur.

1. Your bishop is not blocked by your own pawns.
2. Your opponent will place pieces and pawns on the same color as your bishop controls.

Another example of a bad bishop is a bishop that has to support its own pawn chain, e.g. white has Bb3 and pawns on c2 and a4. As soon as the bishop moves, both pawns become unprotected. A bishop needs

1. Mobility
2. Responsibility to protect no pawns or only the pawn base (e.g. c2 in a c2-b3-a4 chain).
3. Targets to attack (e.g. white has Be3 and pawn on a6; black has pawns on a7 and b6; Bxb6 is a constant threat, as well as Be3-f4-b8xa7).

The less these conditions hold true, the worse bishop you get!
> 1 votes

# Answer
One way "bad bishop" can be defined and avoided is by using Capablanca's rule. 1) If you have a bishop keep most of your pawns on the squares of opposite color. This rule has priority. 2) If opponent has a bishop, limit it by using your pawns. Of course some factors might balance these rules out.

The article below seems to illustrate this very nicely. It shows how a strong player makes a decision about the "quality" of their bishop and based on that decides on the best structure. https://www.chess.com/blog/Illingworth/capablancas-rule
> 1 votes

# Answer
Bad bishops and doubled pawns are both commonly misunderstood. The advice to avoid them is usually based on very superficial observations. If you were to focus your efforts on properly understanding them you should gain a class at least. And understanding takes high precedence over defining.

Look at The Secret Life of Bad Bishops by Esben Lund from Quality Chess
> 1 votes

# Answer
a Bishop is bad if:

* it is blocked by its own pawns
* the position is closed

On the other hand, it is good when:

* it has a wide shooting range (ideally both wings can be targetted at the same time
* The position is opened
* It is not hindered by its own pawns/pieces
> 1 votes

---
Tags: bishops, bad-bishop, positional-play
---


# Question
Title: From where to start learning new tactics?
I know the basics and some basic tactics in chess, but I want to learn new and advanced tactics. Can anybody tell me any source for that?

# Answer
I have tried some of the existing sites that provide exercises.

If you are searching for common tactical position, chesstempo is sure one of the best options with ilimitated free exercises.

If you are searching for incredible checkmates, sacs etc, chess.com has a nice trainer, the problem is it is not free.

You have also lichess. The exercises at this site are taken from blitz games of the players. They use stockfish to generate them. Some of them are doubtful, but a punctuation system is doing his task.

If you want to become a good player in long games (90+30) I recommend you to do lots of exercises at chesstempo, but lichess exercises are nice for tricks and so and totaly free.
> 3 votes

# Answer
There are a lot of sites with random puzzles, but if you want to be systematic I recommend "Encyclopedia of Chess Middlegames: Combinations" This is a large book of puzzles organized into 16 categories. These types of puzzles also appear in any Chess Informant -- which also has endgame puzzles.
> 2 votes

# Answer
chesstempo.com is an excellent site for learning and practicing chess tactics. You can use it for free and the puzzles will adjust based on your success rate from easy to puzzles grandmasters get wrong.

Be sure to read the comments when you get a puzzle wrong as it often reveals some tactic type that you may have never seen before.

They also have a glossary of tactic types.
> 1 votes

# Answer
A good source for newer players would be 303 tricky chess tactics by Wilson and Albertson. I'd recommend going through it multiple times until you can comfortably do about 50 problems a day with no mistakes. That's when you've really maximized what you can learn from that book. Once you can do that chess tempo would be the place to go for more advanced tactics.
> 0 votes

# Answer
Seirawan's books are really informative and fun to read.

He has a Tactics book. It's great and it teaches tactical patterns is a very fun way, and I noticed myself winning with the same tactics I saw in the book a few days after reading them.
> 0 votes

---
Tags: learning, strategy, tactics
---


# Question
Title: What is the Bronstein (delay) equivalent of Fischer time control of game in 90 plus 30 second increment for FIDE rating?
The FIDE Rating Regulations say

> For a game to be rated each player must have the following minimum periods in which to complete all the moves, assuming the game lasts 60 moves. Where at least one of the players in the game has a rating 2200 or higher, each player must have a minimum of 120 minutes.

When increments are used this has resulted in the almost standard time control of all moves in 90 minutes with a 30 second increment from move 1. That way each player has 90 minutes plus 30x60 seconds for 60 moves = 2 hours.

If delay is used instead of increments what is the equivalent time control?

It seems to me that game in 90 minutes plus 30 second delay would not satisfy the requirement for a minimum of 120 minutes for 60 moves. Particularly in the opening players will play moves in under 30 seconds as so have less than 120 minutes for 60 moves.

To guarantee 120 minutes playing time for 60 moves and writing all the moves down would require game in 120 minutes plus 30 second delay.

I have seen 40 moves in 100 minutes, then 60 minutes to finish the game plus 30 second delay from move 1 but this is more generous as each player will have a minimum of 160 minutes, not 120 minutes for 60 moves.

# Answer
> 2 votes
That players will typically not use the full extent of the delay is not relevant. The minimum time requirement refers to the least upper bound of the possible amounts of time the players could theoretically take. Thus, G/90 d30 satisfies the requirement, although it is a very uncommon control.

---
Tags: fide, time-control, chess-clocks
---


# Question
Title: What is the theoretical assessment of this 4 knights gambit?
```
[FEN ""]
1.e4 e5 2.Nf3 Nf6 3.Nc3 Nc6 4.g3 Nxe4!?

```

Some games have followed 5.Nxe4 d5 6.Nc3 d4 7.Nb1 e4 8.Ng1 for example.

# Answer
At depth 19, Komodo gives an equal evaluation (+0) after 8.Ng1 (and according to Komodo all moves were best leading up to that point after 4...Nxe4). However, it says that 8.Nh4 gives White a +0.32 advantage.

It's hard to judge the theoretical assessment just by an engine's evaluation from the 8th move, but there are only a few games played in my database so there's not much to go on. Overall it seems absolutely playable for Black and funner to play from his side of the board. But objectively White probably has some slight advantage.
> 2 votes

---
Tags: opening, gambits, four-knights
---


title: Calculation of national rating

text:
# Question
Title: Calculation of national rating
In order to calculate effect on national rating, should it be enough to choose the relevant k coefficient (assuming this is what makes for the discrepancy between national rating and FIDE rating) and plug it in here: https://ratings.fide.com/calculator\_rtd.phtml ?

Furthermore, is there a resource out there to find k coeffients per country (I'm located in Israel, so if anyone knows that specifically, even better).

# Answer
> In order to calculate effect on national rating, should it be enough to choose the relevant k koefficient (assuming this is what makes for the discrepancy between national rating and FIDE rating) and plug it in here: https://ratings.fide.com/calculator\_rtd.phtml ?

No. For the simple reason that countries use different methods for their rating/grading system. Some use an elo system others don't. England, for instance, uses a completely different system.

If you go to the ECF grading website and click on help, on the left hand side of the page, then towards the bottom of the help there is a section describing how the ECF calculate their grades.

> **HOW ECF GRADES ARE CALCULATED**
> The basic method of calculation is as described in the next few paragraphs. For juniors, however, there are differences as described further down.
>
> Points are allocated in respect of each game. For a win you score the opponent's grade plus 50, for a draw the opponent's grade, and for a loss the opponent's grade minus 50. "Grade" means his grade current at the time of grading. There is a proviso that if your opponent's grade differs from yours by more than 40 points it is assumed to be exactly 40 above (or below) yours. This applies whatever the result.
>
> If an opponent (or the player himself) is ungraded, a "starting grade" is estimated, using all available information. See Estimating a starting grade for an ungraded player below. Note that FIDE ratings are ignored. An opponent who has only a FIDE rating will be treated as ungraded.
>
> In the interval between the end of a grading period and publication of the new grades, the "current" grade for calculation purposes is the new, as yet unpublished, grade.
>
> The grade is calculated by dividing the total number of points scored by the number of games played. If there are 30 or more games in the most recent 12 months, then the grade is based on these games alone. If there are not, it is based on the most recent \** 30 games played; or on all the games played in the last 36 months if that is less. In no case does calculation go back more than 36 months. Where games are brought forward from a previous period, they are not recalculated. The number of points scored for a game always remains the same.
>
> \** "Most recent" has a special meaning here. In principle the program counts backwards till it reaches 30 games. But there are certain disadvantages (see Appendix) to applying this naïvely. Instead, if the 30th game falls part way through a 6-month period, the program will take as many games from that period as it requires in order to make up the 30; but they will be notional games calculated at the average score for the whole 6-month period.
>
> How is "most recent 30" interpreted if a game has been reported late and graded in the "wrong" period? Answer: the game will be listed under the grading period in which it was reported and calculated, and it will go into that period's grade with a notional playing date of 1st January (or 1st July as the case may be). This notional date will be used, where necessary, to determine the game's position in the backward count to 30.
>
> Rounding
> Grades are calculated to the nearest whole number (halves go up). Rounding is done once, at the end. A grade, once rounded and published as a whole number, is henceforth deemed to be that whole number.

You say -

> I'm located in Israel, so if anyone knows that specifically, even better

Really? Do you play chess in Israel? Do you have an Israeli rating? Can you read Hebrew?

I'm guessing some of the answers must be "No" since otherwise you would be better placed than 99.9% of forum members to find out the information for yourself and are only asking out of sheer laziness.

My ICF rating is in the 1800's and my k factor is 12.

Boris Gelfand's ICF k factor is 10 as you can see from the calculations for his Israeli rating from his games played abroad (i.e. converting his opponents' FIDE ratings to ICF and then using them to calculate changes to Gelfand's Israeli rating). This link takes you to Gelfand's ICF rating page and then you will have to click on משחקים בחו"ל (middle / fourth of the box links underneath his main details).

Here is the same page for Liel Levitan, the European Schools girls U7 champion. Her Israeli rating is 1445 and her k factor is 14. Again, on the page click on משחקים בחו"ל to get to the calculation page.

Here is the Israeli rating list (but I don't understand why you couldn't get this for yourself if you are living and playing in Israel?) You can find players of different strengths and ages and check their k factors. I know the ICF website is hard to navigate. I found the old one from about 5 years ago much easier. It used to give the calculations, including k factor, for every game, not just the foreign ones, so including the Israeli ones.

As you can see from the FIDE Ratings Change Calculator you cannot type in any k factor. That means that in general you cannot use this for ICF ratings and for other federations only if they use the same k factors.
> 3 votes

# Answer
What I can recommend myself is to "backtrack" the k coefficient based on historical rating changes. For example, if you know that after a certain game your national rating changed by X points, and you know what rating you and your opponent had before the game, then you could plug that data into the FIDE calculator and try for different values of k to find out what k factor your national rating is based on (assuming it's one of the values that FIDE allows in the dropdown in the calculator).

Otherwise, it's of course also possible to do the same by using the actual ELO equation which is easily Googled or found on Wikipedia.

One word of caution, though: the pre-game rating of the players may be slightly different compared to the last time rating were published, let's say if ratings are published at the beginning of each month and the game took place mid-month after the players had already played a few games and rating changes took place.
> -1 votes

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Tags: rating, elo, fide
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# Question
Title: What's the maximum number of moves that can result in a threefold repetition from an arbitrary position?
Assume that the fifty-move rule does not require a player to claim a draw. Instead, the game is automatically declared a draw if no pawns have been moved and no pieces have been captured in the last 50 moves.

Hence, we don't need to maintain the entire game history to detect threefold repetitions. We only need to maintain a history of the last 100 positions. Out of these 100 positions, half of them are white-to-play and the other half are black-to-play. Hence, only 50 of these 100 positions could possibly be the same as the current position.

Now, out of these 50 candidate positions if each position is repeated twice then we only have 25 distinct positions which could possibly be the same as the current position. Hence, the upper bound on the maximum number of moves that could result in a threefold repetition is 25.

However, it's very unlikely (dare I say impossible?) that there's a position with 25 possible moves that would lead to a threefold repetition. I believe that the actual number is much smaller. We may never know the exact number. Nevertheless, can you prove that the upper bound is lower than 25?

NB. I'm asking this question because I'm developing a neural network that plays chess. Hence, I'd like to reduce the size of the input to the neural network as much as possible. Providing a history of 25 positions to the neural network is a lot.

# Answer
Twelve moves is the maximum:

```
[FEN "5K1k/6p1/6pp/8/8/8/b7/Q7 w - - 0 1"]

1. Qxa2 Kh7 2. Qa3 Kh8 3. Qa4 Kh7 4. Qa5 Kh8 5. Qa6 Kh7 6. Qa7 Kh8 7. Qg1 Kh7 8. Qf1 Kh8 9. Qe1 Kh7 10. Qd1 Kh8 11. Qc1 Kh7 12. Qb1 Kh8 13. Qa2 Kh7 14. Qa3 Kh8 15. Qa4 Kh7 16. Qa5 Kh8 17. Qa6 Kh7 18. Qa7 Kh8 19. Qg1 Kh7 20. Qf1 Kh8 21. Qe1 Kh7 22. Qd1 Kh8 23. Qc1 Kh7 24. Qb2 Kh8 25. Qa3 Kh7 26. Qa4 Kh8 27. Qa5 Kh7 28. Qa6 Kh8 29. Qa7 Kh7 30. Qg1 Kh8 31. Qf1 Kh7 32. Qe1 Kh8 33. Qd1 Kh7 34. Qc1 Kh8 35. Qb1 Kh7 36. Qa2 Kh8 37. Qa3 Kh7 38. Qa4 Kh8 39. Qa5 Kh7 40. Qa6 Kh8 41. Qa7 Kh7 42. Qg1 Kh8 43. Qf1 Kh7 44. Qe1 Kh8 45. Qd1 Kh7 46. Qc1 Kh8 47. Qb1 Kh7 48. Qa1 Kh8

```

Moving the Queen to a2, a3, a4, a5, a6, a7, b1, c1, d1, e1, f1 or g1 all lead to threefold repetition.

As @RemcoGerlich explained the Black pieces have to reset for the positions to be the same. Black is resetting after every other move (on moves 2, 4, ..., 48) in the example above which is the quickest possible.

Thirteen moves would require the Black pieces to reset at least 26 times however Black can reset at most 25 times in 50 moves.
> 9 votes

# Answer
Maybe I don't understand your question very well. Obviously, there can be a threefold repetition with the first occurence of the repetition being 50 (or 49 so that the 50-moves rule doesn't apply) moves ago and the second occurence happening 25 moves ago.

There are lots of cases when you can reduce the input to the neural network, for instance each time a pawn is move or a capture is made or castle rights are lost the count is reset to one position. But the upper bound remains 25.

Check positions after moves 1, 26 and 50 in this fantastic game, a fighting draw:

```
[FEN ""]
1.e4 e5 {first occurence} 2.Ba6 Ba3 Bb5 Bb4 Bc4 Bc5 Bd3 Bd6 Be2 Be7 Bh5 Bh4 Bg4 Bg5 Bf3 Bf6 Nh3 Nh6 Be2 Be7 Ba6 Ba3 Bb5 Bb4 Bc4 Bc5 Bd3 Bd6 Ng1 Nc6 Be2 Be7 Bh5 Bh4 Bg4 Bg5 Bf3 Bf6 Qe2 Nb8 Bh5 Be7 Qd1 Ba3 Be2 Bb4 Ba6 Bf8 Bf1 Ng8 {second occurence} Nc3 Nc6 Ba6 Ba3 Bb5 Bb4 Bc4 Bc5 Bd3 Bd6 Be2 Be7 Bh5 Bh4 Bg4 Bg5 Bf3 Bf6 Nh3 Nh6 Be2 Be7 Ba6 Ba3 Bb5 Bb4 Bc4 Bc5 Bd3 Bd6 Ng1 Nd4 Nb1 Ng8 Ba6 Ba3 Bb5 Bb4 Bc4 Bc5 Bd3 Bd6 Be2 Nc6 Bb5 Bf8 Bf1 Nb8 {third occurence}

```

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Thanks to @RemcoGerlich comment, I understand now that your question was very different. Here is a game situation where 12 different moves can lead to a threefold repetition. I think it is the upper bound; as explained by Remco in a comment to your question.

```
[FEN ""]
1.e4 e5 a4 Nh6 Qh5 Ng8 Ba6 Nh6 Qd1 Ng8 Qg4 Nh6 Bf1 Ng8 Bb5 Nh6 Qd1 Ng8 Qf3 Nh6 Bf1 Ng8 Bc4 Nh6 Qd1 Ng8 Nh3 Nh6 Bf1 Ng8 Bd3 Nh6 Ng1 Ng8 Na3 Nh6 Bf1 Ng8 Ra2 Nh6 Nb1 Ng8 Nc3 Nh6 Ra1 Ng8 Ra3 Nh6 Nb1 Ng8 Qh5 Nh6 Ra1 Ng8 Ba6 Nh6 Qd1 Ng8 Qg4 Nh6 Bf1 Ng8 Bb5 Nh6 Qd1 Ng8 Qf3 Nh6 Bf1 Ng8 Bc4 Nh6 Qd1 Ng8 Nh3 Nh6 Bf1 Ng8 Bd3 Nh6 Ng1 Ng8 Na3 Nh6 Bf1 Ng8 Ra2 Nh6 Nb1 Ng8 Nc3 Nh6 Ra1 Ng8 Ra3 Nh6 Nb1 Ng8 Ra1 Nh6

```

Now any of the 12 moves Qh5, Qg4, Qf3, Ba6, Bb5, Bc4, Bd3, Ra2, Ra3, Na3, Nc3 or Nh3 would lead to a threefold repetition.
> 2 votes

# Answer
> NB. I'm asking this question because I'm developing a neural network that plays chess. Hence, I'd like to reduce the size of the input to the neural network as much as possible. Providing a history of 25 positions to the neural network is a lot.

There are simpler ways to check for 3-fold repetition than feed the game history to a neural network -- you should not do that, it's very odd design decision, and in my opinion you'd better focus on getting NN playing chess better than solving the edge cases that can easily be dealt with in just a few lines of code.
> 2 votes

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Tags: mathematics, threefold-repetition, 50-move-rule
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