# Question
Title: Looking for resources on a sideline of the Caro Kann, 1. e4 c6 2. Nc3 d5 3. Qe2
```
[fen ""]
1. e4 c6 2. Nc3 d5 3. Qe2 d4 4. Nd1

```

I find this variation very interesting and would like to know whether it has a name, is in some books, or maybe just annotated games. It is played mostly by Russian players: Aleksei Pridorozhni, Vadim Zvjaginsev, Semen Dvoirys are listed with the most games and very convincing scores.

# Answer
> 3 votes
I have several Caro-Kann books and none mention this line.

In general, http://www.kenilworthchessclub.org/, and https://www.chessgames.com/ are good opening resources.

When you're analyzing rarely played lines it's best to just use a database and an engine. That's all I really use anymore anyway. Occasionally, I'll look at book if I don't understand a particular move but mostly it's database and engine.

White is getting crushed in this line. After 4. Nd1, e5, black is at least equal. I don't know why you'd want to play it. Something like the 2 knights or the KIA would lead to similar positions but are better openings.

# Answer
> 1 votes
The Chess Tempo website has an opening explorer database. It has a number of follow ons at from numerous master level+ games, with win and draw percentages for each variation. According to its data, **4... e3** looks better for Black than d4. EDIT clearly that should be e6 as noted by B Swan \]

Fun fact: Tartakover used to play Nf3 instead of Qe2.

---
Tags: opening, analysis, caro-kann
---


# Question
Title: Is the London system a good chess opening for beginners?
Is the London System opening is a good opening to invest on for getting deep on its variation for a beginner player (rank 1000-1100)? actually I heard it's a boring and systemical opening and for example **GM Hikaru** doesn't like this opening (I see his reactions on his stream when someone plays it), although I saw some amazing game that **Magnus Carlsen** played with London System.

# Answer
It depends.
Any system (almost) can be good/bad for you/your\_opponent depending on many factors.

You should pick one opening you like that fits your personality/style of play. And then master that opening. Be prepared to change as you improve though as what worked against beginners may not be as good against masters and GMs
> 3 votes

# Answer
Your question asks for opinions, which isn't correct form. So it'll be closed or you'll be asked to re-frame it, something like that.

My opinion is no, and beginners shouldn't worry about openings or what GMs think of openings. Learn tactics and endings.
> 2 votes

---
Tags: opening, london-system
---


# Question
Title: Knight + King vs Knight + King - Loss on time
I am quite new to chess and I wonder what someone can do about the following situation:

* Me (white): Knight + King, 1 minute left
* Opponent (black): Knight + King, 3 minutes left

By the following rule:

> If only one player has exceeded the time limit, but the other player does not have (theoretically) sufficient mating material, the game is still a draw. Law 6.9 of the FIDE Laws of Chess states that: "If a player does not complete the prescribed number of moves in the allotted time, the game is lost by the player. However, the game is drawn if the position is such that the opponent cannot checkmate the player's king by any possible series of legal moves, even with the most unskilled counterplay." For example, a player who runs out of time with a sole king versus king and bishop does not lose the game. It is still possible to lose on time in positions where mate is extremely unlikely but not theoretically impossible, as with king and bishop versus king and knight. (Under USCF rules, king and bishop, king and knight, or king and 2 knights with no pawns on the board is not considered sufficient mating material, unless the opponent has a forced win, even though it is theoretically possible to mate (but extremely unlikely to happen) in situations such as K+B vs. K+N).

this is no immediate draw.

The opponent keeps running away until I am out of time and lose the game.

A sample game can be seen here (I blundered on move 60 here, I could have got his knight but I pre-moved everything because I had around 5 seconds time left). But we can see here that he also does not take my knight to not make it a draw so I lose on time.

# Answer
You have three choices:

1. Always play with an increment, then this won't arise because you can always move within the increment
2. Try and fork your opponent's king and knight. Either he takes your knight or you take his knight next move - result = draw. Or the best and simplest with so much time left
3. Just play very fast until you have made 50 moves without any pawn moves (there won't be any because there are no pawns left) and without any captures (if there are any then the game sill be draw.)

One minute should ample time for you to just make 50 moves with your knight. Quality doesn't matter in this case.

According to the FIDE Laws of Chess:

> 9.3 The game is drawn, upon a correct claim by a player having the move, if:
>
> 9.3.1 he writes his move, which cannot be changed, on his scoresheet and declares to the arbiter his intention to make this move which will result in the last 50 moves by each player having been made without the movement of any pawn and without any capture, or
>
> 9.3.2 the last 50 moves by each player have been completed without the movement of any pawn and without any capture.

Most online servers implement this automatically. If 50 moves are made with no pawn moves and no captures then the server ends the game as a draw.
> 11 votes

# Answer
1 - Play faster.

2 - Lose your knight and then the program will call it a draw.

3 - Move your king around for 50 moves and claim a draw; see answer 1.

4 - Play OTB instead of online. Find the Director and claim the draw for lack of material to mate.
> 2 votes

---
Tags: rules, endgame, draw
---


title: Glicko-2 Rating System: Bug or exploit?

text:
# Question
Title: Glicko-2 Rating System: Bug or exploit?
I originally had this posted on Stack Overflow as it could be a bug in the implementations, but some suggested I post to math. I just found this Stack Exchange, and I thought who better? Some of you may know off the bat whether this seems accurate or not, without the need for debugging.

---

Glicko-2 is a rating system used in chess but can be used in many other situations. Glicko-2 is an improvement on Glicko-1, which addressed problems of the older ELO rating.

What makes Glicko-2 special in comparison to version 1 is that it incorporates a higher rating deviation (RD) the longer someone has been inactive. It does this with the notion of a system constant which relates to time/rating periods.

An example write-up from the author is found here: http://www.glicko.net/glicko/glicko2.pdf.
Within this document, he explains:

> The Glicko-2 system works best when the number of games in a rating period is moderate to large, say an average of at least 10-15 games per player in a rating period. The length of time for a rating period is at the discretion of the administrator.

Making an assumption that a group of active chess players plays 10-15 games on average in a 1 month time period, the administrator would then update ratings at the end of every month.

---

I needed a PHP Implementation of the Glicko-2 rating system and came across the following:

**Glicko-2 JavaScript Implementation**

* The JavaScript had a small error, which didn't let it match the technical write-up example, the author found it close enough, and didn't bother to debug.

**Glicko-2 PHP Implementation**

* The PHP implementation was plagued with many bugs, but that wasn't apparent unless you did more than one rating period (which the technical write-up never shows expected values of)

**Glicko-2 Calculator in Excel**

* Finally, the Excel calculator seemed to be error-free and the most professional, done by someone in the chess community. Once the JavaScript bug was solved, the JavaScript and Excel Calculator matched very closely with each other (albeit not perfect, could be within rounding error)

I had fixed the bugs (and submitted issues/patches to the authors) I could find on the PHP and JavaScript versions to match as closely to the Excel Calculator.

---

Now I am 99% confident that I have an accurate Glicko-2 implementation (between the 3 of them) for analysis and that is when I came across something strange, and the topic of this discussion.

Given the suggested default for Glicko-2 for a new player:

```
Rating:      1500
RD:           350
Volatility:  0.06

```

If you face an average opponent of rating 1378 and RD 99 (source) only once every rating period (1 month) for the next 12 periods (1 year) you will have accumulated an assumed **National Class A** (1800-1999) rating of 1852 when in reality you have only beaten 12 average rated players over a span of 12 months.

```
Month   Rating      RD      Volatility      Class
1       1625        259     0.059999        National Class B
2       1682        225     0.059998        〃
3       1718        205     0.059997        〃
6       1784        174     0.059994        〃
12      1852        148     0.059988        National Class A
24      1922        127     0.059976        〃

```

If you face 2 average opponents every rating period, you can get to National Class A about 4-5 months, facing only 8-10 average opponents.

```
Month   Rating      RD      Volatility      Class
1       1672        215     0.059999        National Class B
2       1733        183     0.059997        〃
3       1770        166     0.059995        〃
4       1797        154     0.059993        〃
5       1819        146     0.059992        National Class A
6       1836        140     0.059991        〃

```

---

Are these assumptions accurate? Is there a bug in my calculator?

If it is not a bug, what are some ways of countering this besides:

* Consider "true rating" to be lower bound of the deviation (Rating - RD)
* Do not show inactive user's rating
* Do not show users with less than N games

# Answer
I worked on a Scala implementation a few months ago, although it was a bit unpolished--I should go back to finish it. I at least got some reasonable results from it.

If you win every game you play, yes, your rating will grow to be quite high even if you play against only low rated players. The probability that you will win every game against such an opponent is probably about what a class A player would achieve (although it probably is a bit inflated due to the relatively high RD, still).

The best way to counter, in my opinion, is to not consider someone with an RD over a certain amount to be a stable rating--i.e. consider it to be "provisional". Also, in order to actually gain a title, at least in USCF, they have a system of norms, where you must perform at a certain level in a tournament of 4 games or more (4 times, I believe), which makes the likelihood of playing against a ~1378 for the whole tournament \[four times\] very unlikely.

Is your goal to use this for chess? What is your use case?

Update: FICS handles it by only considering people with an RD of \<80 active. (They use Glicko-1, still, I believe.) http://www.freechess.org/Help/ficsfaq.html#Q005.003

And by the way, Glicko-1 uses RD/time decay as well. Glicko-2's main improvement was the "volatility" factor, which allows people with erratic results or stable results to be calculated very slightly differently. I think it's a very minor tweak to Glicko-1 which causes considerable extra calculation--but like you, I was still interested in calculating it. I actually asked Glickman himself for some additional datapoints for testing, but he was too busy to supply them at the time.
> 12 votes

# Answer
All rating systems have problems in real life. At best none of them can do more than approximate a guess at your ability.

They will do better at the GM level as those players are more consistent and tend to play more GMs; while the rest of us are more inconsistent and tend to play a wider range of lower rated players who are also more inconsistent. And new players tend to improve far faster while playing in fewer tournaments which further skews all the ratings. And at any level some players have off days or do not try as hard if it wont change their position in the final results.

Trying to fine tune ratings so much like Glicko2 is a fools errand.

Another factor exacerbating the problem is that players tend to play the same players. If there were a worldwide mandatory swiss system that played enough rounds there would be a big shake up in most players ratings. A worldwide double round robin would make some more changes but the swiss would be a good start to fixing rating errors -- at least in the middle with established players. You still have the problem with new players distorting the ratings.
> 0 votes

---
Tags: rating, glicko-2
---


# Question
Title: Are there studies showing that descriptive notation is easier to use for blindfold than algebraic notation?
What studies have compared effectiveness for thinking by chess players using descriptive vs algebraic notation?

# Answer
> 2 votes
If there are studies, they'd show descriptive to be the lesser of the two because in descriptive, all the squares have two names; in algebraic, just one. So if you're having to keep a game in your head, it's easier to do so with 64 identifiers to remember than 128, right?

If you practice playing blindfolded, you'll find that your only use for notation is transmitting the moves back and forth.

# Answer
> -1 votes
descriptive is far easier for blindfold chess or blind players

the symmetry makes it easier to 'see' the board where with algebraic it is all memory and computation to really know what is where

---
Tags: psychology, notation, studies-published-report
---


title: Grunfeld Defense as White

text:
# Question
Title: Grunfeld Defense as White
This opening gives White a big center and aims to destroy it. I have trouble playing the exchange variation as White because Black has great piece activity while my pieces are stuck in passive positions. Is there another variation which also allows White to get a big center while minimising problems?

# Answer
I think Bronstein had the right idea in the Exchange Grunfeld against Boleslavsky in the 1st game of the 1950 candidates final. It costs a little material, but it's White who got the active pieces, while the center expanded.

```
[FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
[Event "Bronstein - Boleslavsky Candidates Playoff"]
[Site "Moscow URS"]
[Date "1950.07.31"]
[EventDate "1950.07.31"]
[Round "1"]
[Result "1-0"]
[White "David Bronstein"]
[Black "Isaac Boleslavsky"]
[ECO "D87"]
[WhiteElo "?"]
[BlackElo "?"]
[PlyCount "63"]

1. d4 Nf6 2. c4 g6 3. Nc3 d5 4. cxd5 Nxd5 5. e4 Nxc3 6. bxc3
c5 7. Bc4 Bg7 8. Ne2 O-O 9. O-O cxd4 10. cxd4 Nc6 11. Be3 Bg4
12. f3 Na5 13. Bd3 Be6 14. d5 Bxa1 15. Qxa1 f6 16. Bh6 Qb6+
17. Kh1 Rfd8 18. Rb1 Qc5 19. Bd2 b6 20. Bb4 Qc7 21. Rc1 Qb7
22. Qb1 Rab8 23. dxe6 Nc6 24. Bc3 Ne5 25. Bb5 Rbc8 26. Bxe5
Rxc1+ 27. Qxc1 fxe5 28. Bd7 Qa6 29. Ng3 Qxa2 30. h4 Rf8
31. Qg5 Rf6 32. Qxf6 1-0

```
> 2 votes

---
Tags: opening, grunfeld-defense
---


# Question
Title: How can I scan a chessboard and obtain its FEN?
I am planning to create a chess puzzle book for beginners. Diagrams need to be published in the book. Right now I have all the materials in PDF. But I need a software to create diagrams for a particular chess position. Is there any way to scan chess diagrams from a PDF?

# Answer
> 9 votes
This website has a chess ebook reader available for scanning chess diagrams from PDF: https://chessvision.ai/

Additionally they also have browser extensions for Chrome and Firefox which is really handy in scanning images of positions on any web page.

# Answer
> 7 votes
I wrote a program that can recognize positions from books and magazines and give you the FEN. Here is the web interface for Chessputzer

You can upload the image or paste directly from the clipboard.

**Note**: it is designed for the the most common fonts used in print. It won't work for images from Chessbase etc. For that, use Fenbot.

My aim was to make it good enough to read blurry images from old chess books so it should be pretty tolerant of artifacts and such.

# Answer
> 6 votes
Chessfimee can perfectly serve you.

It scans and analyses chessboards with chess diagrams, puzzles. All you need is to use the camera to take a photo of a chess diagram from books, papers, even LCD screens (PDFs, other sources). Also you can share the chess position (FEN) with other chess applications.

An iOS version will be coming soon.

# Answer
> 4 votes
Try the following. You upload the image, it scans and generates FEN. I don't know if it will read a pdf but converting a pdf to a common graphic format is not hard.

Chess Grabber

I tried it using the diagram from this posting. It generated its determination of the diagram and this FEN:

`rn1qk1nr/Pp4P1/2p2P2/4P2p/1bp5/2NbPPP1/PP2N1BP/B1BQ1RK1 w kq - 0 1`

# Answer
> 1 votes
CheSScan app available on Play/App Store does what you are looking for.

chesscan.com

Disclaimer: I am the developer of the app.

# Answer
> 0 votes
Search "Chess diagram fonts". There is a LOT of stuff out there

# Answer
> 0 votes
There's also ChessOCR, which I found useless, but as we always say, your mileage may vary.

https://play.google.com/store/apps/details?id=com.kgroth.chessocr&hl=en\_US

---
Tags: software, fen, diagram
---


title: Popularity of the Scotch Game

text:
# Question
Title: Popularity of the Scotch Game
I was looking back at a game played between Hikaru Nakamura and Magnus Carlsen at the 2017 London Chess Classics in which Hikaru employed the Scotch game and played very creatively getting a winning advantage at one point. In the end, however, he failed to win it and the game ended in a draw. If any of you haven't seen it yet, I recommend to check it out since it's a real bloodbath!

There have also been many great players who have used it such as Garry Kasparov who never lost a single game with it! I have been wondering why it isn't used at the top level for a long time, but never got a chance to ask it. Could someone please explain why it isn't used at the top level?

# Answer
I think you are on to something, and statistically, there is a very good reason to play the Scotch over the Ruy Lopez, but that might not be all there is to it.

I think that the main reason is that we are taught that the Ruy Lopez is THE most classical opening, and is the best. I have seen that mindset in SO many books written by the top players over the years, in particular, Karpov. Also, I was watching "Method in Chess" videos recently, and GM Dorfman said that white is statically better because white has more space, and black is confined to three ranks, and white can play on the kingside, center, or queenside, and thus, black must always be on the lookout. I think that is just what classical Soviet players were taught, and that mindset has not been broken among the elite, especially since so many of them became trainers in other countries after the breakup of the Soviet Union.

Statistically, you are right on the money.

All the top players I looked at had similar results to Kasparov, meaning an overwhelming plus score with it. I left out Anand, Aronian, So, MLV, and Grischuk from the following list since they played it so few times (less than 6 each), it was clear that their reason was simply surprise.

1. Carlsen 11-1-6 (wins-losses-draws) 78%
2. Caruana 5-0-6 72%
3. Nepomniachtchi 34-6-29 70%
4. Nakamura 13-6-7 63%

These are against all players, and the problem is that in Carlsen's case, in particular, is most of the games were from when he was not the Carlsen we know today, and I could have left him out. Caruana's games were virtually all against elite competition!

Then I decided to search only for all games in the Mega 2020 database with players both above 2700, and then the stats fell dramatically down to a typical winning percentage for white, 58% even (53-25-97, 175 games total).

When I then did the same thing for 2700 players playing the Ruy Lopez, there were 2366 games with a breakdown of 580-373-1412, or only 54%.

That is still a healthy plus for the Scotch, but maybe the Soviets still were right, and that the only reason the stats for the Scotch are so good is that the opponent was not expecting it as much. Also, I did not attempt to look at hundreds of games to identify where the games where lost. It might have just been due to other circumstances.
> 7 votes

# Answer
I don't know about the top players *these* days, but Morphy handled all of his open games with the idea that when he played d2-d4, he wanted it to stick. So that meant two things, either 1. e4 e5 2. f4, when the e5-pawn is deflected away, or 1. e4 e5 2. Nf3 Nc6 3. Bc4 Bc5 4. b4! Bxb5 5. c3 plus d2-d4.

When Kasparov — whose opponents were a little better than Morphy's — revived the Scotch, he was working with a slightly less advantageous pawn formation:

```
4k3/ppp2ppp/3p4/8/4P3/8/PPP2PPP/4K3 w - - 0 1

```

White is pretty much guaranteed this slightly-better pawn structure in every open game, because when d2-d4 comes, Black is usually compelled to give up some center space with the swap.

Kasparov seemed to take into account something that no other master did for 150 years. Compare that pawn formation to the one that arises after 1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4. Why is White willing to give up the better center pawn for the wing pawn? One, because Black loses a little space and White gains a little. Two, more important, White gains time with the recapture. Kasparov said "hey, I can get the same advantage in time and space in the Scotch, but Black is trading a center pawn instead of a wing pawn." At Kasparov's level, that slight gain of time and slight gain of space is enough to build from.

Time passes, fashion changes. When one strong player decides he doesn't like some evaluation at the end of a topical variation, other strong players go along, and so do the 1300 players.

In my view, the elite decided that Morphy was right, that White should probably be aiming for both pawns in the center instead of merely e4-vs.-d6. Then the fashion became 1. e4 e5 2. Nf3 Nc6 3. Bc4 or 3. Bb5, plus a slow d2-d3, c2-c3, d2-d4.

Opening theory is like *Vogue* magazine, that's all. What's fashionable today won't be fashionable tomorrow. No matter what opening book publishers will have you believe, your only task in the opening is to reach a playable middlegame. Chessplayers save years of wasted study when they get around to accepting this.
> 1 votes

# Answer
Dont confuse small sample statistics and results from a top player with the quality of the opening.

Scotch is popular with beginners who want to play a wide open slash and burn tactical game as they can often beat other beginners who are not familiar with all the opening variations.

Also they would rather lose a fun game than learn how to win a positional game that they think is boring.

It is far less popular with top players who know how to play black properly because their result is more likely to be a draw or loss which would mess with their final tournament standing and prize amount.
> -1 votes

---
Tags: opening, carlsen, scotch-game, aggressive-play, nakamura
---


# Question
Title: What proofs for refuted gambits are there?
I've stumbled upon this article a while ago, and I've also seen refutations for the Muzio Gambit (Joseph Kling & Bernard Horwitz - Chess Studies on Endings of Games). I'm wondering what other gambits are proven to be unsound.

Edit: I'm looking for refuted gambits in the strict sense of the word, followed by proof. Even though a gambit might be playable against someone who doesn't know its refutation, the gambit is still considered refuted if it is proven that the side who initiated the gambit loses in all variations worth looking at against best play. So yes, I'm looking for scientific proof.

Also, if a database of almost all games played in a particular gambit shows that the side that initiated the gambit wins almost all the time, this doesn't mean that there isn't a way for that gambit to be refuted, it just means that if there is a way, most people haven't played it.

Above everything, I'm looking for material to learn from. An article that says that Vasik Rajlich or someone else has used a computer cluster and came to a conclusion regarding a certain position, how will I benefit from it if there is no proof? **(And please note that that King's-Gambit-busted-by-Rajlich article was in fact a Chessbase April Fools' joke!)**

# Answer
> 16 votes
As long as chess can't be calculated from beginning to end, it is very hard to scientifically prove an opening to be refuted (aside from lines that leave you with such hopeless situations like a bare king against king and rook, of course).

If you are satisfied with a less scientific proof, I'd say gambits are even less so refuted. In my opinion, nearly all gambits are playable, as long as you won't play it against a superhuman database/program or a world champion. In a practical sense, probably no gambit worth of having a name is refuted in the sense of not being playable. Even if a gambit is widely considered unsound and often results in a worse position, it might contain enough steam to give your chess skill ample opportunities to overpower your opponent.I even remember a game where I suffered terrible against the BDG because I didn't find any refutation over the board. I only won because my opponent terribly misplayed the late midgame, but from the opening point of view he should have won the game.

So my answer is: No gambit I know of is refuted to the degree of being unplayable.

# Answer
> 10 votes
Many gambits are unsound. The proof is told by the number of these played at the highest levels of the game. So, if you don't see the Blackmar-Diemer gambit at top tournaments, you can assume that its disadvantages outweigh its advantages. The King's Gambit is one famously busted opening.

That being said, we're not top players. Most of us can't beat the players who can't beat the top players. I'd wager, charitably, that 75% of the moves we make are wrong, technically.

In short, they're probably all playable. As always, if you're going to take chances, book up first. Understand the opening, know the main lines.

# Answer
> 8 votes
A gambit can be proven to be unsound by using a modern chess engine. Having said this, I would like to mention a comic gambit, known as the Fred defense:

```
[FEN ""]
1.e4 f5 2.exf5 Kf7 3.Qh5+ g6 4.fxg6+ Kg7 5.gxh7 Rxh7 6.Qg4+ Kh8

```

White has picked up 2 pawns. In return, the black king has done an artificial castle and black's pieces are ready to develop and kick the white queen around the board. The next plan for black is to launch an attack on the white king and catch it before it has time to castle. Also, the plan is to firmly grab the center, which will restrict the development of white's pieces. To theoretically refute a gambit is one thing. To refute it while sitting at the board is a totally different game altogether. That is why gambits are so much fun!

# Answer
> 6 votes
I believe there are a few gambits completely solved, that is, analyzed up to positions that either the material advantage is enough to guarantee a win or this win is achieved by means of technique (if the final position is not directly checkmate). The only one that I know a proof of, however, is the Latvian Gambit:

```
[FEN ""]
1.e4 e5 2. Nf3 f5

```

The Spanish analyst Alejandro Melchor provides two very insightful .pgn with what he considers to be the refutation of said defense. Here you may download the first one and here you may download the second one. He also wrote an appendix.

They both are deep in calculations and very detailed, if you ever want to play perfect chess against this gambit, then good luck. Even if a gambit is "refuted", not many know these lines and the ensuing complications. This makes almost any gambit, refuted or not, completely playable (provided you are not facing a super-GM).

P.D.: I had to upload the files via a third party, I hopes it's not inconvenient, since I don't know if it's possible to upload files directly via Stackexchange.

# Answer
> 3 votes
Here is an article that describes a way to compare (and refute) chess openings.

http://papers.ssrn.com/sol3/papers.cfm?abstract\_id=2415203

# Answer
> 1 votes
First of all, to refute a gambit, we need to analyse all the lines to a \[forced\] win. For example, the Latvian Gambit will result in all lines ending with a material advantage for White able to guarantee a win.

However, for the Muzio Gambit, there is no such proof. Black will eventually have to give a knight back to reduce White's initiative, so there is no proof at all.

EDIT: I ran a bunch of games through Stockfish depth 22 with the Muzio Gambit, and Black eventually loses the knight and the position reaches equality.

# Answer
> 1 votes
The Damiano Defense, also known as the five pawns gambit, is practically refuted. You can find the details on the Wikipedia page. The key line is:

1. e4 e5 2. Nf3 f6? 3. Nxe5! fxe5? 4. Qh5+ Ke7 5. Qxe5+ Kf7 6. Bc4+ d5 7. Bxd5+ Kg6 8. h4 h5 9. Bxb7

After which Black cannot stop Bxa8 with a decisive material advantage for White.

---
Tags: opening, analysis, theory, gambits, evaluation
---


title: Lisitsin gambit vs From's gambit

text:
# Question
Title: Lisitsin gambit vs From's gambit
The Lisitsin gambit usually involves a bishop on d3 and a knight on g5. From's gambit has only a bishop on d6, but the gambit-accepting side has less development than the Lisitsin. How would this affect the play in both openings, and is the Lisitsin gambit good while the From Gambit dubious?

# Answer
> 6 votes
As a person who has experience in the Bird's and Dutch openings, I would say that both of them are somewhat bad responses to the Birds or Dutch. In the From's, generally white has the edge but its not as if black doesn't have counterplay. In the Lisitsin, usually something like 1Nf3 f5 2e4 fxe4 3Ng5 Nc6 4d3 e3 is something close to equal.

There is a version of the from's gambit that goes 1f4 e5 2fxe5 d6 3exd6 Bxd6 4Nf3 Nf6, which is similar to lisitsin as black often plays Ng4. In the "main" variation of the froms, black is playing g5 and white typical response is to play g3, d4 Qd3. In the lisitsin, however, as white is more developed, black often gives the pawn pack to neutralize the attack.

**So the answer the question, The main difference between the from's gambit and the lisitsin gambit is that in the Froms gambit, white often keeps the extra pawn, parries black threats, and has an edge(though positions are often complicated with chances for both sides). In the Lisitsin gambit, white's attack is often neutralized because black gives back his extra pawn in order to not allow white to develop the light square bishop quickly. The game is close to equal.**

So in both gambits, if the acceptor doesn't hasn't much knowledge in the gambit, it can be very dangerous. However, if the acceptor is an experienced dutch player or bird player, then there will be no problems and the gambiteer would have had better chances with more mainstream responses.

# Answer
> 2 votes
Chessplayers need to think of the opening more in terms of plans than in moves. Whether either the From or Lisitsin is good or bad, and any benefit from White's additional move in Lisitsin isn't as important as familiarity with this pattern:

```
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1
[Result ""]
1. g4 e5 2. f3 Qh4#

```

Oh, everyone knows *that* one. But it's at the heart of From's Gambit, because 3...Bd6 threatens mate in 3.

Relating the Fool's Mate pattern to Dutch and Bird games enables you to play many good ones. I always get a kick out of Teed-Delmar because Delmar was such a good player:

```
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1
[White "teed"]
[Black "delmar"]
[Result "1-0"]

1. d4 f5 2. Bg5 h6 3. Bh4 g5 4. Bg3 f4 5. e3 h5 { Part of the disaster stems
from Black being good enough to find a move like this. Qh5+ is cut off by the
rook, and if 6. exf4, then 6...h4 traps the bishop in a different way.}  6. Bd3
Rh7 7. Qxh5+  1-0

```

And this one:

```
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1

1. d4 f5 2. h3 Nf6 3. g4 fxg4 4. hxg4 Nxg4 5. Qd3 Nf6 6. Rxh7

```

We used to think Gibaud-Lazard was the shortest game by masters on record: 1. d4 Nf6 2. Nd2 e5 3. dxe5 Ng4 4. h3 Ne3 0-1

There are dozens or hundreds of brilliant miniatures in the From Lisitsin family. Play in that style, and you'll enjoy it tremendously.

---
Tags: analysis, gambits, froms-gambit, lisitsin-gambit
---


title: What should be the next move for Black?

text:
# Question
Title: What should be the next move for Black?
Both sides have had equal points untill now. If the Black knight is moved, then White can move their knight with discovered check. What should Black do?

```
[FEN ""]
[StartPly "11"]

1. e4 e5 2. Nf3 d6 3. d4 Nf6 4. dxe5 dxe5 5. Nxe5 Nxe4 6. Qe2

```

# Answer
> 1 votes
Based off your position; I let the engine play it out and the below was the "best" output I received. This is just an old fashioned slog for the centre. A lot of trading going on.

```
[Event "Analysis Request"]
[Site "?"]
[Date "2020.09.09"]
[Round "?"]
[White "Unknown"]
[Black "Unknown"]
[Result "*"]
[SetUp "1"]
[FEN "rnbqkb1r/ppp2ppp/8/4N3/4n3/8/PPP2PPP/RNBQKB1R w KQkq - 0 1"]
[PlyCount "10"]

1. Qe2 Qd5 2. Nd3 Be7 3. f3 Nd6 4. Nf4 Qc6 5. Nd3 O-O *

1. Qe2 Ngf6 2. Nd2 Qd5 3. Nxe4 Nxe4 4. Qb5+ c6 5. Qxd5 cxd5

```

Based of the board; Blacks castled to safety, the white Queen is in danger of (Re8 ... Bh4+). White feels "under developed" and has less control of the board.

---
Tags: opening, analysis, positional-play, philidor-defense
---


title: Is there a forced win in CastleChess?

text:
# Question
Title: Is there a forced win in CastleChess?
Is there a forced win for White or Black in the chess variant CastleChess? The rules are explained in this post on an obscure blog named “Cinquante signes”, although it is originally from chessvariants.com.

The rules are the same as the orthodox ones, but with two big differences.

> White wins via checkmate or if Black can no longer castle queenside. If either the Black king or queenside rook move, of if the rook is captured, Black can no longer preform queenside castling, and thus they lose.

> Black can win by giving mate or castling queenside.

The devil is in the details, and there are some questions on the blog that help give insight into whether or not it can be solved.

> Q.(b): Is it easy for Black to castle long (and immediately win the game)?

Well, if White is not prudent, yes -in theory, 5 moves are enough for Black to win.

> Q. (c): Are draws still possible?

Oh yes, if it's White turn to play for instance, and White is (a) not in Check (b) in check if it moves, the game is a draw (as in orthodox chess).

> Q. (e): Do you have any strategic advice?

Yes-there are weaknesses in Black's position. White could focus on: the pawns a7, b7 and f7 for instance.

> Q (f): And what about Black's defense?

This position is solid-and, in a few moves, Black might be able to castle long and win: put all Black pieces on their starting square, except 3 — the e7 pawn is on e6; the b8 Knight is on c6; the f8 Bishop is on b6.

# Answer
A million years ago, a friend showed a very simple variant: One random pawn on each side is marked, and if it's captured (by a move that isn't checkmate), the capturing side loses.

The Danish Gambit was popular that night, but otherwise, people were flinging pawns around, planning to win with the variant rule (I guess you could call it a truly poisoned pawn). I said to my friends that I thought the right strategy was no strategy: Just play chess, and try to win the chess game. You'll lose a few games by chance, but you'll also win a few.

Was I right or wrong, I won't say. Maybe you'll try that variant yourself to test both ways of handling it.

I'm a very big fan of the 3 Check variant (so is Karpov). That game messes with your mind. The nitwits who try to win by delivering a third check run out of sacrificial fuel, while playing normally is dangerous, because the variant rule is often just a matter of tactics (that is, some combination that makes one or two checks while sufficiently exposing the king for more).

I gave this castle chess thing some thought, and I was amused by the different winning conditions. White is likely to go nuts in search of a short combination to prevent castling, while Black (I think) should play normally but with a view toward O-O-O.

Is there a forced win for White? I doubt it, and after that bit of thought, I began to favor Black.
> 1 votes

---
Tags: chess-variants, solving
---


# Question
Title: Systematic ways to approach more difficult problems
As I’m done solving easy puzzles (1000–1500), I decided to try some 1700 puzzles, but I’m finding it very hard to solve them as there are no obvious checks, captures and threats. Also, most of the times, the solution are about 5–7 moves. So, I figured that maybe a complete different approach is needed to solve these problems.

```
r1b2r1k/p1p3pp/2pp1q2/8/N1Q2n2/1P1N4/P1P2PPP/3RR2K b - - 0 1

```

For example for this one, I don’t even know where to begin. I solved easier problems by finding all the checks, captures and threats, and the solution used to come within few seconds, but now things are not that easy. So is there a systematic approach?

# Answer
> for example this one below,don't even know where to begin.Earlier the way I solved problems was finding all the checks,captures and threats and the solution used to come within few seconds but now things are not that easy

"Finding all the checks,captures and threats" looks like a great way to solve the puzzle you've posted. There are no immediate checks but there are some good candidate captures and threats.

```
[fen "r1b2r1k/p1p3pp/2pp1q2/8/N1Q2n2/1P1N4/P1P2PPP/3RR2K b - - 0 1"]

1... Nxd3 2. Qxd3 Qxf2? 3. Rf1! (1...Be6? 2. Qxf4! Qxf4 3. Nxf4 Rxf4 4. Rxe6)(1...Nxg2 2. Kxg2 Bh3+ 3. Kxh3 Qf3+ 4. Kh4 g5+ 5. Kxg5 Rf5+ 6. Kh6 Qh5++)

```
1. Nxd3 is a **capture** which looks like it might win the f pawn and create back rank mating threats but white looks to be fine after recapturing with the c pawn when the white queen is still threatening the c6 pawn. If white recaptures with the queen then the f pawn is poisoned! It is met by the embarrassing Rf1. So, that doesn't work
2. The white queen is a little bit short of moves, but the **threat** Be6 is met by Qxf4 and at the end of the exchanges the bishop on e6 is hanging, so that doesn't work either. Finally -
3. The **capture** Nxg2 is a really promising looking sacrifice which is well and truly poisoned. Kxg2 is met by Bh3 and then Qf3+ with mate to follow soon. If white doesn't move the e1 rook then black is just winning a pawn and exchange plus the white king is very exposed. If white does move the e1 rook then Qf3 with the threat of Bh3 is going to be devastating.

So, "checks, captures, threats" *does* work. You just have to keep the analysis going for more than 2 or 3 moves and find two piece sacrifices as you hunt the king. The fun part of tactics!
> 9 votes

# Answer
Your approach won't change, but you see how the depth of the analysis does.

Keep it up; your instinct for the things to examine first improve, eventually.
> 2 votes

# Answer
First, nearly all problems are going to be solved by forcing moves (checks, captures, threats) on the first move. Occasionally, you run across more subtle problems where the first move is a quiet move but those are often zugzwangs and they aren't that common.

Second, It's good to look at the weaknesses in the position especially hanging pieces ie "that knight isn't protected, how could I win it? "

Third, sometimes it helps to change up the move order.

Also, 5-7 move combinations are NOT 1700 rated problems. I've often heard (and I agree) that if you can see two moves ahead you're playing around 1800 level chess.
> 2 votes

---
Tags: learning, problems, calculation
---


# Question
Title: A chess problem: White to play and mate in two
**White's turn, checkmate in two moves**

```
[FEN "r1b2k1r/1p2bppp/p1B2q2/8/8/8/PPPQ1P1P/2KRR3 w - - 0 1"]

```

How does White deliver checkmate in 2 moves?

# Answer
This is a fairly simple one:

> 1. Qd8+ Bxd8 2. Re8#
> 1 votes

# Answer
There is piece that is not allowing mate by white. Just force this piece to move.

> Qd8+ Bxd8 Re8#
> 1 votes

# Answer
White can back-rank(sort of)Black after 1. Qd8!. This move deflects the bishop onto d8(only legal move), allowing 2. Re8#.
> 1 votes

# Answer
The problem is a simple brute force (i.e. sacrifices and/or checks) tactic that teaches how to see back-rank weaknesses and how to open up lines.

Solution:

> 1. Qd8+! (A forcing move that gives Black no move but to respond to) Bxd8 (The only legal move available) 2. Re8# (This shows the point giving up the queen-to force the Black bishop to open up the e-file as to allow the rook to move and give a mate that takes advantage of the Black king’s extremely bad position and misplaced pieces.)
> 0 votes

---
Tags: checkmate, problems
---


# Question
Title: Why did Puzzle Rush stop at the second fail?
I was playing the popular Puzzle Rush game on chess.com (3-minute version), and the game stopped when I missed the second puzzle (I had 8 seconds left on the clock). The statement is "Three strikes and you are out!", and it usually complies.

I must clarify that **this is not the updated version of Puzzle Rush**, which started at 9 a.m. Pacific time on Thursday, November 21.

It's the second time I’ve seen this happen. I am wondering if there is a special rule that I have missed, or if it is just a bug.

# Answer
> 2 votes
There is a 'quit' flag on the webpage of puzzle rush, so perhaps you could have accidentally clicked it.

# Answer
> -2 votes
The web version as implemented by chess.com is laggy and your clock runs down without you knowing when the browser is loading and the timer is suffering severe latency problems.

I created the original Prototype A of this puzzle app style and it was lag proof but chess.com copied it and didn’t know how to avoid this issue.

---
Tags: online-chess, puzzles
---


# Question
Title: As Black, what is the fastest way to beat Gnu Chess on easy mode?
This is more of a puzzle. As far as I can ascertain, Gnu-Chess on easy mode always plays the same movesm What is the least amount of moves required to beat Gnu Chess on easy mode? Just to clarify, you are playing as Black, Gnu Chess is playing as White.

# Answer
> 2 votes
Here is the fastest way that I've found.

```
[Event "?"]
[Site "?"]
[Date "2014.07.12"]
[Round "?"]
[White "?"]
[Black "?"]
[FEN ""]

1. Nc3 d5 2. Nf3 d4 3. Ne4 b6 4. d3 f5 5. Ne4g5 h6 6. Nh3 g5 7. Bd2 g4 8. Nhg1 gxf3 9. Nxf3 Nc6 10. Bf4 h5 11. h3 Bh6 12. Ng5 e5 13. Bxe5 Nxe5 14. Nf3 Nxf3+ 15. gxf3 Nf6 16. Rg1 Rg8 17. Rxg8+ Nxg8 18. Bg2 Bb7 19. a4 a5 20. Kf1 Nf6 21. Qe1 Nd5 22. Rd1 Nf4 23. e4 Qe7 24. e5 O-O-O 25. Ra1 Rg8 26. Bh1 Qg5 27. Rb1 Qg1#

```

# Answer
> -1 votes
here how I win against gnu chess version 6.2.2 as black:

1. Nf3 d5
2. d4 Nf6
3. c4 e6
4. Nc3 c6
5. e3 Nbd7
6. Bd3 dxc4
7. Bxc4 b5
8. Bd3 a6
9. O-O Bb7
10. e4 Qc7
11. dxe6 fxe6
12. Bc2 c4
13. Ng5 Nc5
14. Qf3 Bd6
15. Qh3 O-O-O
16. Re1 Kb8
17. Nf3 e5
18. Bg5 Nd3
19. Bxd3 Rxd3
20. Qh4 bxa4
21. Nxa4 Bb4
22. Bxf6 Bxe1
23. Rxe1 gxf6
24. Qxf6 Re8
25. Nc3 Rd6
26. Qg5 Rg6
27. Qe3 Rd8
28. Nd5 Bxd5
29. exd5 Rb6
30. d6 Rbxd6
31. Nxe5 Rd5
32. h3 Qc5
33. Qc3 Qd4
34. Nxc4 Qxc3
35. bxc3 Rd1
36. Kf1 Rxe1+
37. Kxe1 Rd3
38. Nb6+ Kb7
39. Na4 Rd8
40. c4 Rd4
41. Nb2 Kc5
42. f4 Rd8
43. Ke4 Rb8
44. Nd3+ Kxc4
45. f5 {White resigns} 0-1

---
Tags: engines, puzzles, solving
---


title: Move comparison in this opening

text:
# Question
Title: Move comparison in this opening
In this opening, being White, I want to understand, for the next move, why is e4 not as strong a move as e3 or Nf3? I am a beginner.

```
[FEN ""]

1. c4 e5 2. Nc3 Nc6

```

# Answer
> 5 votes
With e2-e4, you create "holes" at d3 and d4 that can never again be attacked by pawns. Any enemy pieces that land on those holes have to be kicked out by your pieces, which is harder to do (because every piece runs away from a pawn job).

World champion Botvinnik used to set pawns on c4-d3-e4 which we call The Botvinnik Triangle. The world champion can live with those holes, but beginners have a tougher time.

Beginners shouldn't be playing 1. c4. If you'd played 1. d4, we wouldn't be having this conversation.

# Answer
> 4 votes
What everyone has said about the "hole" on d4 is logical; However looking at what Magnus Carlsen has done recently, e4 may be just as good!

I am referring to: 1.c4 e5 2.Nc3 Nc6 3.Nf3 Nf6 4.e4

Usually e4 is played after Black has committed d7-d6 blocking the dark squared bishop as it was thought that Black is immediately equal after 4...Bc5 or 4...Bb4. But Magnus has shown his ideas for White in these positions and it has become a trendy way of playing.

So then it comes to whether 3.e4 is the same and would transpose. The only thing I see is that Black could continue to delay the development of his King's Knight in the hopes of perhaps developing it to e7 or playing f5 before developing it to f6.

for example:

1.c4 e5 2.Nc3 Nc6 3.e4 Bc5 4.Nf3 d6 with the idea of f5!?

I don't think it is a refutation of Whites play but it is an option Black doesn't have after 3.Nf3 Nf6 4.e4

I would argue that if your intent is to put your knight on f3 then move 3 is the time to do it, but in this line you have to deal with the 3...f5 lines.

# Answer
> 3 votes
There're several long-term reasons to avoid 3.e4.

1. You permanently weaken the d4-square. This is dangerous because it's a central square. In the short term, Black can already play ...Nd4, plus ...Bc5 is another natural developing move that increases control of the square.
2. You stop your own long-term plans. You need some knowledge of how pawn structure works to see this, but the idea is that at some point, you need to advance your pawns to mark out space and create an attack. If you play 3.e4, then you can no longer play d4 or f4 easily in the future (since your e-pawn can no longer support those advances), but if you can't play those two moves then it's not obvious how you're going to set up your play. Black is ready to fight you on the queenside via ...a5, if necessary.
3. In the same way, it becomes harder to dislodge the pawn on e5. This is an important pawn, in fact it's likely Black's most important pawn in the position. It's on a central square controlling two more central squares d4 and f4, and it marks out space. Challenging it is an important part of White's plan, which is why e3 intending d4 or f4 is a key idea for White. Playing e4 gives up this plan.
4. Finally, e4 puts the pawn on a light square. This makes it difficult for your f1-bishop to find a diagonal. In these 1.c4 formations, the natural place to put the bishop is on g2, where it together with the c4-pawn & c3-knight can control the central d5-square. With a pawn on e4, the g2-bishop will be blocked. Conversely, 3.e3 does temporarily block the c1-bishop, but after a future d4 the bishop will gain an open diagonal. The light square bishop cannot look forward to such a future after e4.

# Answer
> 1 votes
After e3, white can follow up with d4 and will have a better center. The pawns on c4 and d4 control three of the four center squares while black only controls two.

e4 is similar to a Maroczy bind which isn't too bad despite the weak squares it creates. However, in this specific position, black hasn't committed to much so black has a lot of ways to combat it.

1. Nd4 possibly followed by c5
2. At some point playing c6 followed by d5. That's not available in the Sicilian because black commits to c5 on move 1.
3. The f5 pawn break.

# Answer
> 0 votes
For me personally, I think the main idea for e3 and Nf3 is to allow d4. Contrastingly, e4 doesnt help in the pushing of d4. Therefore it’s stronger.

---
Tags: opening, analysis, beginner
---


title: How to beat the Scandinavian Defense?

text:
# Question
Title: How to beat the Scandinavian Defense?
As a person(~2170 uscf) who has recently started playing the scandinavian defense(Qd6), and has played against the scandinavian defense on the white side, I find it hard to get any sort of meaningful edge as white and often pretty much equalize with black. Yet in the top level, it's rarely seen in classical chess. Thus, it seems that there should be particular variations in the Qa5, Qd6, and Qd8 scandinavians that put it out of business. What are these lines?

# Answer
> 4 votes
Here are some lines. They seem to be the mainlines from the master database on Lichess. White is not winning, but the opening phase went White's way.

...Qd6

```
 [fen ""]
    1. e4 d5 2. exd5 Qxd5 3. Nc3 Qd6 4. d4 Nf6 5. Nf3 (5...a6 6. g3 Bg4 7. Bg2 Nc6 8. O-O O-O-O
    9. h3 Bh5 10. Bf4) c6 6. Ne5 Nbd7 7. Nc4 Qc7 8. Qf3 {note that this move prevents ...b5!!} Nb6 9. Bf4 Qd8 10. Be5 (10. h3 Qxd4?! 11. Rd1 Qc5 12. Be3 {is very good for White}) Bg4 {if not played now, White will prevent it with h3 and then O-O-O} 11. Qg3 {Black has to defend his g4-bishop now, as it is hanging after Bxf6}

```

...Qa5

```
[fen ""]
1. e4 d5 2. exd5 Qxd5 3. Nc3 Qa5 4. d4 Nf6 5. Nf3 c6 6. Bc4 Bf5 7. Bd2 e6 8. Nd5 Qd8 9. Nxf6+ gxf6 (9...Qxf6 10. Qe2 {with O-O-O next}) 10. O-O

```

...Qd8

```
[fen ""]
1. e4 d5 2. exd5 Qxd5 3. Nc3 Qd8 4. d4 Nf65. Nf3 Bg4 6. h3 Bxf3 (6...Bh5 7. g4 Bg6 8. Ne5 Nbd7 9. Nxg6 hxg6 10. g5 Nh5 11. d5 {with a huge clamp, Black has problems to make purposeful development}) 7. Qxf3 c6 8. Be3 e6 9. Bd3 Nbd7 10. O-O-O

```

# Answer
> 2 votes
There's nothing wrong with the Scandinavian. The reason why it has fallen out of favor is because it gives White a slight advantage, and Black loses some tempi with the queen.

---
Tags: opening
---


title: Which White piece moved only once?

text:
# Question
Title: Which White piece moved only once?
Here is a chess problem that uses retrograde analysis. I’ve also posted it on the “France-Echecs” chess forum, which is in French of course, and on my blog.

```
[FEN "3qk3/3pp3/8/8/8/3PP3/1PP2PP1/RNBQKBNR w - - 0 1"]

```

Each of the eight White pieces on the first rank has made exactly three movements, except one of them who made only one. Which piece is it?

# Answer
According to the pawn structure, one of the white bishop must be a promoted one. The knights have switched place, the other pieces can easily make three movements.

The only ones that can make a single one are the rooks, either by

1. Castling
2. Taking the other rook's square
3. By coming from a promoted pawn on a8 or h8

All possibilities seems doable as white can promote two pawns, and can use a captured piece to capture all black pieces.

Here is an example:

```
[fen "rnbqrnbq/ppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w - -"]

1. d3 a5 2. e3 h5 3. Bd2 b6 4. Be2 g6 5. Bxa5 Bb7 6. Bxh5 Bg7 7. Bxb6 Qc8 8. Bxg6 Kf8 9. Bxc7 Nc6 10. Bxf7 Nf6 11. a4 Nd8 12. h4 Ne8 13. Bxd8 Qxd8 14. Bxe8 Kxe8 15. a5 Qc7 16. h5 Kf7 17. a6 Qd8 18. h6 Ke8 19. axb7 Qc7 20. hxg7 Kf7 21. bxa8=B Qd8 22. gxh8=B Ke8 23. Nc3 Qc7 24. Nf3 Kf7 25. Qd2 Qd8 26. Ke2 Ke8 27. Ra5 Qc7 28. Rha1 Kf7 29. Rh5 Qd8 30. Rhh1 Ke8 31. Qe1 Qc7 32. Kd2 Kf7 33. Qd1 Qd8 34. Ke1 Ke8 35. Ne2 Qc7 36. Nd2 Kf7 37. Nb1 Qd8 38. Ng1 Ke8 39. Bf3 Qc7 40. Bc3 Kf7 41. Bd2 Qc8 42. Be2 Kf8 43. Bc1 Qd8 44. Bf1 Ke8

```

In this example rook h1 makes a single move while other white pieces on the first row make three moves.
> 6 votes

---
Tags: problems, retrograde-analysis
---


# Question
Title: Why is 16. d5 a blunder in this position?
In this position I'm White and I have just played 16. d5. Stockfish labels the move as a blunder. I do understand I had better moves than this, and it's not the move I would play if I were to get this position again, but why is it a blunder? It doesn't seem that bad. My reasoning was that, having the bishop pair and better development (two minor pieces playing versus one), and Black having a somewhat vulnerable king, I could benefit from opening some lines with the pawn-break.

```
rn4k1/pbp1qr2/1p1pp2p/3P1pp1/2P5/2PBP1B1/P1Q2PPP/R4RK1 b - - 0 16

```

# Answer
The move 16. d5 is not necessarily a blunder. Although it is not good for White, it is not losing. Lichess and other chess engines sometimes see positions differently from how humans would percieve them.

That being said, analysis on chess.com deems it a a mistake. which is much more reasonable. The reason is that, in the long-term, the d5 pawn mught be lost, giving Black a +1 advantage, in material worth, at the least **in some lines.** Even if White retains a pawn, the doubled pawns on the queenside will be a disadvantage that Black can use, or there will be some other disadvantage Black can create for White.

All in all, White will have some sort of positional weakness no matter the outcome.

Here is a computer generated line that shows how Black gets the upper hand in the long-term with an extra pawn. I do not claim that this is the 100% best play, just that it shows one of the many general outcomes where Black has an advantage.

```
[FEN "rn4k1/pbp1qr2/1p1pp2p/5pp1/2PP4/2PBP1B1/P1Q2PPP/R4RK1 w - - 0 1"]

1. d5 Nd7 2. Rae1 Raf8 3. f4 Nc5 4. e4 fxe4 5. Bxe4 gxf4 6. dxe6 Bxe4 7. Rxe4  Nxe4 8. exf7+ Rxf7 9. Rxf4 Rxf4 10. Bxf4

```

Note that although f4 is technically an inaccuracy, it is perhaps best by human play.

Here is another line that shows how Black can get an advantage in other ways as a result of White’s mistake.

```
[FEN "rn4k1/pbp1qr2/1p1pp2p/5pp1/2PP4/2PBP1B1/P1Q2PPP/R4RK1 w - - 0 1"]

1. d5 Nd7 2. Rae1 Raf8 3. f3 Ba6 4. Be2 e5 5. e4 f4 6. Bf2

```
> 4 votes

# Answer
While this is not a tactical blunder as far as I can see (maybe positional mistake is a better word), playing d5 gives away the c5 square for black's knight to occupy; it's a very strong outpost for black's knight. In the long run, the c3-c4 pawn duo is going to be weak, and especially the c4 pawn is awkward to defend. This is a common theme in, say, the Nimzo-indian, where black manages to fix and attack a weak pawn on c4; if you want to learn more about this strategic theme, you should watch some videos on the Nimzo.

Therefore, we can see that the only reason d5 is not a catastrophic positional blunder is because black cannot justify the immediate ...e5 push due to the weak f5-pawn. In fact, if black can somehow defend that weakness in the near future, white is going to be in grave danger from a positional perspective.

So, what are the virtues of playing d5 in the given position? The only one I can think of is that it destabilizes the f5 pawn. I'm seriously questioning whether white is really well-adviced to take on e6, letting black's queen take aim at the c4 pawn.

What I immediately saw when looking at the position immediately before 16.d5 is that the bishop on g3 is rather unproductive and close to being trapped. Therefore I would consider pushing my f-pawn to give it some space. Also, I'd note that the pawn on f5 was weak, and if attacked black would be forced to respond. Therefore I would consider trying to play for an e4 break rather than a d5 break to open up the position for my bishops. I'd be seriously tempted to push my f-pawn, either to f3 (to support an eventual e4 push) or the immediate f4 push, just being more direct and aggressive, harrassing the g5 pawn for good measure (this is the computer's first choice by far, with f3 being the second. Note that white doesn't need to support e4 with a pawn to push e4, but rather only needs to make sure that the g3 bishop isn't trapped after an e4 push).

Quick addendum: I'd also like to point out that white is seriously ahead in development, which calls for more direct measures than the d5 push. Strike while the iron is hot!
> 2 votes

# Answer
16...f4 seems to win your Bg3.

16...ed 17.Bf5 dc wins a pawn.

To answer the comments: I am not claiming that these are the computer-approved lines of best play. Just pointing out some immediate reasons why you might not want to play d5. 16...ed 17.cd f4 is likely a better version of the f4-push, because there will be no pawn on e6.
> 1 votes

# Answer
Was a Nimzo-Indian, yeah? Or at least you've got a pawn structure that arises from a Nimzo.

When White plays d4-d5, it's what Black wants, because after e6-e5, the white c- and d-pawns are fixed as targets. Black would've loved for the knight to have been on c6, because than d5 pushes it to a5 where it combines with the bishop on a6 to hit the c4 pawn.

Even if the knight can't find a5 to hit c4, it'll go to d7, then c5, where it can never be kicked away by a white pawn.

See, you've got the bishops in that position, so you're striving to open the game for the bishops, not play d4-d5, enabling Black to immobilize your queenside pawns.
> 0 votes

---
Tags: analysis, positional-play, blunder
---


# Question
Title: Example of a Karpov vs. Kasparov game with a controversial move
Full disclosure: I'm not a regular chess player. This question is because I'm writing a book about alternate timelines, and I want to use a game in a real life famous chess match as a point of divergence. I'd like an occasion in which a sizeable portion of pundits and specialists thought a different move should have been made, and the player who made that move lost the game, or squandered an allegedly easy win for a draw.

It'd be great if it was in the 1984/85 Karpov/Kasparov championship match, but any headlines-making match at any point in history would do. It could be Kasparov vs. Deep Blue, or Karpov vs. Korchnoi, for example.

If I use your suggestion, I promise I'll properly credit you. *And* the players involved. Even if it's a computer.

# Answer
> 20 votes
If you don't mind going a bit earlier, then it has to be 1972 Spassky–Fischer (mother of all World Championships) Game 1.

Fischer played 29...Bxh2? a move that few players would consider in light of the obvious 30.g3, trapping the bishop.

**EDIT** Later analysis (Speelman 1981) showed that the game is not lost (and can be drawn with extremely precise play), though the move was sub-optimal and the line becomes really sharp after 30. g3. The real blunder happened on move 37 with 37...Ke4 instead the optimal move again was just 37...a6. However, going by principles and elementary tactics 29...Bxh2? was an unnecessary move and chances are Fischer overlooked the fact that the trapped Bishop couldn't be saved.

# Answer
> 17 votes
Kasparov's `7...h6?` in the game below cost him the game and the match, and later Kasparov accused Deep Blue team of cheating.

```
[FEN ""]
[Event "IBM Man-Machine"]
[Site "New York, NY USA"]
[Date "1997.05.??"]
[EventDate "?"]
[Round "6"]
[Result "1-0"]
[White "Deep Blue (Computer)"]
[Black "Garry Kasparov"]
[ECO "B17"]
[WhiteElo "?"]
[BlackElo "?"]
[PlyCount "37"]

1.e4 c6 2.d4 d5 3.Nc3 dxe4 4.Nxe4 Nd7 5.Ng5 Ngf6 6.Bd3 e6
7.N1f3 h6 8.Nxe6 Qe7 9.O-O fxe6 10.Bg6+ Kd8 11.Bf4 b5 12.a4
Bb7 13.Re1 Nd5 14.Bg3 Kc8 15.axb5 cxb5 16.Qd3 Bc6 17.Bf5 exf5
18.Rxe7 Bxe7 19.c4 1-0

```

https://www.chessgames.com/perl/chessgame?gid=1070917

I would also like to suggest a move from a final game of the tie-break in Kramnik - Topalov from classical-Fide championship unification match in 2006. With `44...Rxc5` Topalov went from difficult position to instantly losing. The match was full of controversy if this is what you are looking for.

```
[FEN ""]
[Event "Kramnik - Topalov World Championship Match"]
[Site "Elista RUS"]
[Date "2006.10.13"]
[EventDate "?"]
[Round "16"]
[Result "1-0"]
[White "Vladimir Kramnik"]
[Black "Veselin Topalov"]
[ECO "D47"]
[WhiteElo "?"]
[BlackElo "?"]
[PlyCount "89"]

1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 e6 5.e3 Nbd7 6.Bd3 dxc4 7.Bxc4
b5 8.Be2 Bb7 9.O-O Be7 10.e4 b4 11.e5 bxc3 12.exf6 Bxf6
13.bxc3 c5 14.dxc5 Nxc5 15.Bb5+ Kf8 16.Qxd8+ Rxd8 17.Ba3 Rc8
18.Nd4 Be7 19.Rfd1 a6 20.Bf1 Na4 21.Rab1 Be4 22.Rb3 Bxa3
23.Rxa3 Nc5 24.Nb3 Ke7 25.Rd4 Bg6 26.c4 Rc6 27.Nxc5 Rxc5
28.Rxa6 Rb8 29.Rd1 Rb2 30.Ra7+ Kf6 31.Ra1 Rf5 32.f3 Re5 33.Ra3
Rc2 34.Rb3 Ra5 35.a4 Ke7 36.Rb5 Ra7 37.a5 Kd6 38.a6 Kc7 39.c5
Rc3 40.Raa5 Rc1 41.Rb3 Kc6 42.Rb6+ Kc7 43.Kf2 Rc2+ 44.Ke3 Rxc5
45.Rb7+ 1-0

```

https://www.chessgames.com/perl/chessgame?gid=1431697

# Answer
> 11 votes
Not exactly what you're looking for, but in his 1987 match vs Karpov, Kasparov forgot to press his clock during time pressure. Kasparov finally lost that game, the result being heavily influenced by the clock's incident.

https://www.latimes.com/archives/la-xpm-1987-10-15-mn-14340-story.html

https://apnews.com/d00b24ebff5eede461c2587317bcef62

That a professional chess player forgets to press his clock after making a move is quite an extraordinary event.

# Answer
> 11 votes
We'll never know the whole truth of the 1951 world championship match. Years after the Soviet Union collapsed, and nearing death, Bronstein *still* wouldn't talk about it.

The challenger Bronstein was the son of an imprisoned Jewish dissident, while champion Botvinnik was a model Soviet (dichotomy much the same as Korchnoi and Karpov in the '80s). In the memoir *The Sorceror's Apprentice*, all Bronstein would say was that he was "under great psychological pressure, and it was up to \[him\] how \[he\] dealt with it."

We've speculated over 57. Kc2?? in Game 6 for decades, and whether Bronstein resigned prematurely in Game 23 is also a source of doubt.

I don't think Bronstein felt he was permitted to win that match. And he didn't *lose* it, he *tied* it. Like he knew all along he could've taken the title away if he thought he and his family could survive that.

```
rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1
[Event "Botvinnik - Bronstein World Championship Match"]
[Site "Moscow URS"]
[Date "1951.03.26"]
[Round "6"]
[Result "0-1"]
[White "David Bronstein"]
[Black "Mikhail Botvinnik"]

1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 d6 6.Bg5 e6 7.Qd2
h6 8.Bxf6 gxf6 9.O-O-O a6 10.f4 Bd7 11.Kb1 Be7 12.Be2 Nxd4
13.Qxd4 Qa5 14.Rhf1 h5 15.Rf3 Qc5 16.Qd2 Bc6 17.Re3 Qa5 18.Bf3
O-O-O 19.Qd3 Rd7 20.h4 Kb8 21.a3 Bd8 22.Ka2 Qc5 23.Re2 a5
24.a4 Bb6 25.b3 Rc8 26.Qc4 Qxc4 27.bxc4 Rh8 28.Kb3 Rdd8 29.Rd3
Bg1 30.Red2 Kc7 31.Ne2 Bf2 32.Rd1 Bc5 33.Ng3 Rdg8 34.Ne2 Rh7
35.f5 e5 36.Nc3 Bd4 37.Rxd4 exd4 38.Rxd4 Rhg7 39.Ne2 Rxg2
40.Bxg2 Rxg2 41.Nf4 Rg3+ 42.Kb2 Rg4 43.Nxh5 Rxh4 44.Nxf6 Kb6
45.Rxd6 Kc5 46.e5 Rd4 47.Rxd4 Kxd4 48.Ng4 Bxa4 49.e6 fxe6
50.f6 Be8 51.Kb3 e5 52.c3 Ke4 53.Nh6 Kf4 54.f7 Bxf7 55.Nxf7 e4
56.Nd8 e3 57.Kc2?? Kg3 0-1

```

# Answer
> 2 votes
In Game 5 of Karpov vs. Korchnoi for the World Championship in 1978, Korchnoi missed a forced mate when he played Be4+ instead of Bf7+ on move 55. The game ended as a lengthy draw.

https://www.chessgames.com/perl/chessgame?gid=1068051

The match was being played as first to 6 wins with draws not counting, and neither player had won a game out of the first four. The match ended as a 6-5 win for Karpov in 32 games after Korchnoi nearly came back from the 5-2 deficit he faced after 27 games. Korchnoi won games 28, 29, and 31, and drew game 30, tying the match at 5-5 before Karpov won Game 32 to retain his title. Had Korchnoi won Game 5 and every following game played out the same, he would only have been down 5-3 following game 27 and the following three victories would have won Korchnoi the match in 31 games.

This was a dramatic match that had bizarre allegations of cheating, as Guest\_On\_StackExchange mentioned in the comments to the original post. Additionally, this match had a similar dynamic to the match friscodelrosario mentioned, with Korchnoi being a Soviet defector challenging a Soviet champion. Korchnoi winning could have fascinating political/propaganda impacts on your alternate timeline.

Details of the forced win: 55. Bf7+ 55.. Kc6 (forced) 56. Qe6+ 56.. Kb5 or Kb7

If Kb5: 57. Qc4+ 57.. Ka4 (forced) 58. Qa6#

If Kb7: 57. Qxe7+ Black can play Nd7, Kc8, Kc6, Ka6, or Ka8, but all are lost

If Nd7 then Qxd7+ and Ka8 Qc8# or Ka6 Bc4+ b5 Qxb5#

If Kc8 then Qc7#

If Kc6 then Qc7+ Kb5 Bc4+ Ka4 Qxa7#

If Ka6 then Bc4+ b5 Qd6+ Kb7 Qb8+ and Ka6 Bxb5# or Kc6 Qc7#

If Ka8 then Qd8+ Kb7 Qc7+ and Ka8 Qb8# or Ka6 Bc4+ b5 Qc6#

# Answer
> 1 votes
Unfortunately this example does not come from the 1985 match, but Kasparov arrived at the final game of the 1987 rematch needing to secure a win. He made an unusual choice by going for the English Opening for the first time ever against Karpov, ending in a great success. The game can be seen at https://www.chessgames.com/perl/chessgame?gid=1067242

Nobody will ever know what could've happened had Kasparov tried something else, but it'd be interesting to see an alternative timeline where the "old guard" player defeats the "perestroika guy"

---
Tags: kasparov, karpov, fiction
---


title: SCID shortcuts list

text:
# Question
Title: SCID shortcuts list
I don't like the mouse and want to use the keyboard as much as possible. SCID vs PC has a webpage with keyboard shortcuts, but the same does not seem to exist for SCID. This answer to "How to flip the board" discloses the `.` shortcut, which I found documented in `Help > Contents > The Scid main window`, however only a few of them are to be found in that section. Some are spread out in the Help, others might be missing. Where can I find a list of all SCID shortcuts?

# Answer
After `grep`ing the source code, I found them in `/usr/share/scid/tcl/keyboard.tcl` in GNU/Linux (if someone knows the path for other OS please share it).

Also, a comment in that file says

```
> By editing this file you can customize the keyboard shortcuts,
in order to best suit your preferences.
It is not necessary to recompile scid after changing this file.

```

For convenience, I have extracted all the bindings and their corresponding actions below (this is **not** proper TCL syntax, it is just for reading convenience).

```
<Left>                Back
<Right>               Forward
<Up>                  Back 10 moves
<Down>                Forward 10 moves
<Home>                Exit Variation/Go to game start
<End>                 Go to game end
<Alt-F4>              Exit
<Control-o>           Open a database
<Control-w>           Close the current database
<Control-z>           undo
<Control-y>           redo
<Control-n>           new game
<Control-s>           save game
<Control-S>           save as new game
<F11>                 toggle fullscreen
<period>              flip/rotate board
<s>                   ::setupBoard
<KeyPress-v>          show variations dialog
<Control-Key-$i>      Change current database
<F6>                  ::book::open
<F12>                 ::CorrespondenceChess::CCWindow
<Control-F12>         ::CorrespondenceChess::OpenCorrespondenceDB; ::CorrespondenceChess::ReadInboxg
<Alt-F12>             ::CorrespondenceChess::OpenCorrespondenceDB; ::CorrespondenceChess::FetchGamesg
<Control-equal>       ::tb::Open
<Control-d>           ::windows::switcher::Open
<Control-e>           makeCommentWin
<Control-i>           ::windows::stats::Open
<Control-l>           ::windows::gamelist::Open
<Control-m>           ::maint::OpenClose
<Control-p>           ::pgn::OpenClose
<Control-t>           ::tree::make
<Control-E>           ::windows::eco::OpenClose
<Control-K>           ::ptrack::make
<Control-O>           ::optable::makeReportWin
<Control-P>           ::plist::toggle
<Control-T>           ::tourney::toggle
<Control-X>           crosstabWin
<F2>                  "::makeAnalysisWin 1 0"
<F3>                  "::makeAnalysisWin 2 0"
<F4>                  .analysisWin1.b1.bStartStop invoke g
<F5>                  .analysisWin2.b1.bStartStop invoke g
<Control-A>           makeAnalysisWin
<Control-Shift-2>     "makeAnalysisWin 2"
<Control-a>           sc_var create; updateBoard -pgng
<Control-B>           ::search::board
<Control-H>           ::search::header
<Control-M>           ::search::material
<Control-KeyPress-U>  ::search:::usefile
<Control-C>           ::copyFEN
<Control-V>           ::pasteFEN
<Control-E>           ::tools::email
<Control-I>           importPgnGame
<Control-D>           sc_move ply [sc_eco game ply]; updateBoardg
<Control-G>           tools::graphs::filter::Open
<Control-J>           tools::graphs::absfilter::Open
<Control-u>           ::game::GotoMoveNumber
<Control-Y>           findNovelty
<F1>                  helpWindow Contentsg
<Control-N>           nameEditor
<Control-slash>       ::file::finder::Open
<Control-Shift-Up>    ::game::LoadNextPrev firstg
<Control-Shift-Down>  ::game::LoadNextPrev lastg
<Control-Up>          ::game::LoadNextPrev previousg
<Control-Down>        ::game::LoadNextPrev nextg
<Control-question>    ::game::LoadRandom
<minus><minus>        addMove null null

<exclam><Return>             "sc_pos addNag !; updateBoard -pgn"
<exclam><exclam><Return>     "sc_pos addNag !!; updateBoard -pgn"
<exclam><question><Return>   "sc_pos addNag !?; updateBoard -pgn"
<question><Return>           "sc_pos addNag ?; updateBoard -pgn"
<question><question><Return> "sc_pos addNag ??; updateBoard -pgn"
<question><exclam><Return>   "sc_pos addNag ?!; updateBoard -pgn"
<plus><minus>                "sc_pos addNag +-; updateBoard -pgn"
<plus><slash>                "sc_pos addNag +/-; updateBoard -pgn"
<plus><equal>                "sc_pos addNag +=; updateBoard -pgn"
<equal><Return>              "sc_pos addNag =; updateBoard -pgn"
<minus><plus>                "sc_pos addNag -+; updateBoard -pgn"
<minus><slash>               "sc_pos addNag -/+; updateBoard -pgn"
<equal><plus>                "sc_pos addNag =+; updateBoard -pgn"
<asciitilde><Return>         "sc_pos addNag ~; updateBoard -pgn"
<asciitilde><equal><Return>  "sc_pos addNag ~=; updateBoard -pgn"

```
> 3 votes

---
Tags: scid
---


# Question
Title: Stafford Gambit Accepted - Qe2 - What to do?
Today I have been playing some new lines I haven't tried before. I am quite fond of the Petrov (Russian) Defense and I found some interesting lines particularly the Stafford Gambit seemed to peak my interest.

I had 2 games today with this line and in both instances white did **6. Qe2**. This I found interesting as the expected continuation in this position is for move 6 for white is d4. I found that countering with Bc5 seemed to work ok but I was curious as to some thoughts about what the best move following Qe2 would be and potential development ideas.

```
[FEN ""]
[Date "2020.08.24"]
[White "Him"]
[Black "Me"]
[ECO "C42"]

1. e4 e5 2. Nf3 Nf6 3. Nxe5 Nc6 4. Nxc6 dxc6 5. e5 Ne4 6. Qe2 Bc5 7. Qxe4 *

```

# Answer
The Stafford is getting popular because of the Youtube videos I guess. I saw it earlier today and just played 5.Be2 to take it out of book and won easily.

It's a trappy opening and you're going to have to accept the fact that not every white move gives you a mate in 2.

The best move is probably Bf5. The downside to Qe2 is that 1) white hinders his own development and 2) the c2 pawn isn't defended. Bf5 takes advantage of both of those facts while protecting the knight Qd4 might be another option. 6...f5 and 6...Qh5 are just bad. The only other options would be moving the knight to c5 or g5.
> 3 votes

# Answer
Rats. I thought I had a 5. Qe2 somewhere... Crap, that colllection of Stafford games was on the stolen laptop.

...Bf5 was a suggestion earlier, right? Then if d3 kicks you back to c5, and d4 hits you again, you can drop back to e6 without blocking the bishop, or go in for ...Ne4 f3 Qh4+ Qf2 (what a mess) .
> 3 votes

---
Tags: opening, gambits, petroff-defense
---


# Question
Title: Is it legal to push the rook with the king when castling?
I've gotten into the habit of pushing the rook over to the appropriate square using my king; that is, I take my king into my hand, I take it to the outer edge of the board, then push the rook to its right place using the king figure. Then, I place my king on the correct square.

I've not played in an over-the-board tournament before, and if I ever do so I'd like to know whether this is okay or whether it's a habit I need to lose.

# Answer
> 6 votes
As long as you -

* only use one hand
* touch the king first
* don't do it in such a way as to disturb the opponent

then it is fine.

---
Tags: rules, castling
---


title: A difficult rook ending

text:
# Question
Title: A difficult rook ending
I need help. In the below endgame, Stockfish and Fat Fritz are optimistic on Whit's winning chances , but Mueller disagrees. What happens with perfect play?

```
[FEN "R7/6p1/P3p1k1/7p/8/5PPP/r7/4K3 b - - 0 1"]

```

# Answer
> 7 votes
This answer is intended to expand upon my comments, and give some concrete lines. Let's discuss the position as I (mistakenly) first thought it was presented:

```
[fen "R7/6p1/P3p1k1/7p/8/6PP/r7/4K3 w - - 0 1"]

```

This position is a draw, no matter who is to move. If White doesn't play a7, then Black's rook will have the option to pick off one of White's pawns on the kingside. So we may as well assume that White is to move, and plays 1.a7. After this, Black will be able to play 1...Kf7, to guard the pawn on e6. Let's examine the resulting position:

```
[fen "R7/P4kp1/4p3/7p/8/6PP/r7/4K3 w - - 0 1"]

```

Note that this position would have been losing for Black if it wasn't for the pawn on g7; if there were no pawn on g7, then White would win by replying with 2.Rh8 followed by 2...Rxa7 and 3.Rh7+, picking up Black's rook. But this plan is not possible at the current moment. So White has two different plans to try out: 1) march the king to b5 to free the rook on a8, or 2) create a passed pawn on the h-file, and try to remove the pawn on g7 by means of playing h6 at some point.

The first plan always fails, since Black will keep their rook on the a-file, and when White's king reaches the 4th rank, Black will place their rook on either a1 or a2. Then, if White plays Kb5, Black will give check with ...Rb1+, chasing the white king around until it decides to come back to the fourth rank, after which Black will once again play ...Ra1/Ra2.

The second plan also fails, since if White manages to create the passer on the h-file, and manages to play h6, then Black doesn't have to respond with ...gxh6, but can instead play ...Kg6 to contain the h-pawn. So the conclusion is that this position is indeed a draw.

Let's move on to the actual position you were asking about.

```
[fen "R7/6p1/P3p1k1/7p/8/5PPP/r7/4K3 w - - 0 1"]

```

This is also a draw, although not as trivial (I originally assumed that White was winning here, but I missed a simple idea that maintains the balance). Here White has an extra f-pawn, but this doesn't really make a big difference in the long run. Black will use the exact same strategy as before, putting the king on f7 and shuffling the rook along the a-file, but here Black has to be a bit more careful with the winning plan that White tries. As before, the plan of bringing the king to b5 for White is not going to work. Neither is an attack on the pawn on e6 very likely to succeed as long as Black's king is left on f7. So White only has two feasible winning plans:

1. create a passed pawn on the f-file, and run it to f6 to remove the pawn on g7, or
2. create a passed pawn on the h-file instead, with the same intention.

The first plan is not going to work well, since White will have to at the very least trade the g-pawn for Black's h-pawn, and then trade another pawn for Black's e6 pawn. At the end of the line, we will end up in the following scenario if White tries winning plan 1:

```
[fen "R7/P4kp1/5P2/8/8/8/r7/4K3 w - - 0 1"]

```

Note that if Black just sits on the position and refuses to take on f6, then White can't really do anything to make any sort of progress (this is what I missed initially); taking on g7 just reduces to a trivial draw, and marching the king to the queenside is a lost cause, as always.

Plan 2 is actually the more dangerous one, and here Black needs a bit of precision to stay out of danger:

```
[fen "R7/6p1/P3p1k1/7p/8/5PPP/r7/4K3 w - - 0 1"]

1.a7 Kf7 2.g4 hxg4 3.fxg4 Ra3 4.h4 Kg6! {This move is absolutely necessary if Black wants to draw. The point is that White was threatening the simple idea of h5-g5-g6+, after which Black is completely lost. Black needs their king on h7 to face this idea.} 5.h5+ Kh7! {Black can also place the king on g5, but then White still has some tricks to look out for. This drawing idea is by far the simplest one.} 6.g5 {with the intention of playing g6+} 6...g6! {This is the point of transferring Black's king to h7; if it were on f7 instead, then White could simply play h6-h7-h8Q, with a completely winning position.} 7.hxg6+ (7.h6= {and Black draws by shuffling the rook along the a-file, chasing White's king away whenever it tries to support the pawn on a7.}) Kg7!= {Black draws by moving the rook along the a-file, and chasing White's king away whenever it tries to support the pawn on a7.}

```

---
Tags: analysis, endgame, rook-endgame
---


# Question
Title: How to calculate the number of combinations for Chess960 positions
Can someone derive how do we get the total number of 960 possible positions for Chess960?

# Answer
You're counting the same position a couple of times and not including the rule that the bishops have to be on opposite colors. (And possible that the king must be between the rooks.)

The actual number is 4 x 4 x (6 x 5) / 2 x 4

4 for the LSB

4 for the DSB

(6 x 5) / 2 for the two knights (halved due to account for the same type of piece being placed)

4 for the queen

1 due to the king must be between the rooks (Without this rule, it would be (3 x 2) / 2 or 1440.)
> 10 votes

# Answer
The bishops must be on opposite colors and the king must be between the rooks for Chess960. Each bishop can go on one of four squares, so there are 4x4 ways.

Now the queen can go on one of the six remaining squares, so the total combinations = 4x4x6.

Now there are five squares for the knights, but the knights are interchangeable, so there are 5C3 = 5!/(3!\*2!) = 10 ways. So that makes the total combinations = 4x4x6x10 = 960.

Now there are three squares for the king and rooks, but since the king must go between the rooks, and the rooks are interchangeable, there is only one distinct way for the rooks and king, so the total number of combinations = 960.
> 9 votes

# Answer
We can permute 8 pieces in 8! =40320 ways. But we have some conditions:

1. Two knights are identical.
2. There must be opposite colour bishops.
3. Rooks are identical.
4. King must be between the rooks.

Now in 8 boxes there are 4 black boxes and 4 white boxes.
We can place the black bishop in one of the 4 black boxes which can be done in 4 ways. Similarly the position of white bishop can be chosen in 4 ways. So there are 4×4=16 ways to choose bishop position.

Now we have 6 more positions to fill.

We have to fix the sequence Rook-King-Rook
To do so we only have to chose three boxes out of 6 which can be done in 6C3 =20 ways.
The other three boxes have to be filled by queen, and two knights. This can be done in 3 ways since knights are identical.
Thus we have 16×20×3=960 positions.
> 7 votes

# Answer
This number is derived by using permutations (an arrangement of objects where the order they're arranged in matters). We have a few variables:

```
n = how many objects there are.
r = how many objects we are taking to arrange.

```

Both n and r equal 8 (since there are eight pieces, and we will be arranging all of them).

```
n = 8
r = 8

```

The formula for Permutations: `n! / (n - r)!`

However, we have a certain number of duplicate objects (such as 2 Knights, 2 Bishops, and 2 Rooks):

```
# Permutations = n! / ( (n - r)!(2!)(2!)(2!) )

= 8! / ( (8 - 8)!(2!)(2!)(2!) )

= 8! / ( (0!)(2!)(2!)(2!) )

= 8! / ( (2!)(2!)(2!) )

= 40320 / 8

= 5040

```

This shows that there are actually 5040 possible "Chess 960" positions.

However, in the game "Chess 960" there are limitations for which squares certain pieces can go on. For example, a Bishop can only go on one of four squares. This causes the number to go down to 960 (decreasing by a factor of exactly 42).

Link for more information
> 5 votes

---
Tags: chess-variants, mathematics, chess960
---


# Question
Title: How does one analyse openings judged dubious by engines?
I have recently picked up the Norwegian Defense (also known as Northsea Defense), `1. e4 g6 2. d4 Nf6`.

All modern engines claim it is not good. But I have great results (14W-1D-5L in 15+10 on 2000 Lichess rating) with it and I am seriously considering adding it to my repertoire, so I would like to do some preparation work, look for critical positions where I would have to know an exact move or a plan to justify my opening.

First I have looked at games in the Lichess database. I was very surprised by Black scores in some of the variations. For example

```
[fen ""]
1. e4 g6 2. d4 Nf6 3. Nc3 d5 4. e5 Ne4 5. Nxe4 dxe4

```

scores 55% for Black in 2000+ rapid and classical on Lichess.

I have also looked at the Master database. I have noted that the character of the game is mainly set within 5 moves by White and gathered some common resulting positions. From there I wanted to work further, so I looked at master games more indepth.

Some are clearly surprised by the opening and choose a timid way to play and Black equalises before move 10. In the more critical tries White keeps the advantage for several more moves, but then lets it go or even slips into a disadvantage. Also, the games where both sides offer resistance are very rare. Very often on move 7 there are 2-4 games.

Following engine lines and picking up moves that were missed is rarely helpful, as the engine of course will mercilessly squeeze the position with inhuman precision and will disarm any initiative without effort, making any active attempts seem futile. Sometimes I do not see why White is better, so I follow the line into endgames that are slightly better, but probably considered equal at sub-master level.

Of course I analyse my own games, but the opponents crumble surprisingly fast once on their own, so the opening does not really get tested much in my own games.

So, how would one proceed to prepare in unorthodox openings apart from learning by his own games?

# Answer
Forget the engines. We are humans (hopefully) and are only interested in how human's play.

The King's Indian Defence (KID), a favorite opening of Tal, Fischer and Kasparov (and now played by Nakamura), has a reputation of being unsound by the engines (some positions are +1 and even +1.5) however for white playing precisely is very difficult.

For instance, the Mar del Plata Variation

```
[fen ""]
1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 O-O 6. Be2 e5 7. O-O Nc6 8. d5 Ne7

```

Stockfish evaluates it to be +1 at a depth of 40.

Simple advice for practical play is to ignore the engine evaluation and focus on the fundamentals in the opening (in the order):

1. Exert pressure over the center (either classical or hyper-modern way)
2. Develop minor pieces
3. King safety
4. Connect the rooks while developing the queen

Needless to say always look out for short tactics as you follow the above and also try to have all your pieces coordinated.
> 7 votes

# Answer
1. You should know how to evaluate an opening position- center, development, king safety. While an engine can be useful for missed tactics, I trust my own evaluation over any engine in the opening.
2. Lopsided database scores can be a clue that the opening may be difficult for your opponent but they aren't perfect particularly at higher levels.
3. Using a GM database and an engine find the most difficult line your opponent can play. If you can live with the end position then it's probably fine. If not, it still might be playable depending on how often that line happens in practice.
> 3 votes

---
Tags: opening, analysis, preparation
---


title: Legality of swapping identical pieces

text:
# Question
Title: Legality of swapping identical pieces
In an offhand blitz game **without** touch-move, my opponent, on his opening move as White, just to be a wise guy, picked up his b1 knight and put it down on f3, then moved his g1 knight to b1, and punched the clock. He did it all with one hand. Apart from rules against distracting or annoying ones opponent, did he make a legal move?

# Answer
> 6 votes
> In an offhand blitz game without touch-move

In other words, you are not playing by the official rules of any chess federation, either national or international. You are playing by your own rules. So, you and your opponent, as the arbiters of the rules you are playing by, are the ones to decide whether or not what was done was legal.

---
Tags: rules
---


title: Engine Evaluation Confused

text:
# Question
Title: Engine Evaluation Confused
The Muzio Gambit is -0.8 by Stockfish depth 22. However, if the f7-pawn is moved to the g-file, the evaluation falls to -3.5. How is that so? Both positions seem fine for White.

```
[FEN ""]
[Title "Muzio Gambit"]

1. e4 e5 2. f4 exf4 3. Nf3 g5 4. Bc4 g4 5. O-O!

```

# Answer
> 5 votes
As for "both positions seem fine for White": well, Black has a significant material advantage after 5...gxf3, so White has to find some compensation. If you don't have a concrete continuation which demonstrates that compensation, I don't think there's any reason to think the engine evaluation is confused.

In both positions, a sensible continuation is 5... gxf3; 6 Qxf3 Qf6; 7 d3. Now in the original position Black has doubled f-pawns and a bad pawn structure; in particular the pawn on f4 can't be supported effectively; when it falls Black will have two isolated pawns. Black stands better but has some weakness that White can try to exploit. In the position with the pawn moved from f7 to g7, Black could play 7... g5 immediately, or alternatively 7... Bc5+ and then 8... g5. Now Black's structure is more solid and White doesn't have anything like enough to justify the material disadvantage.

# Answer
> 3 votes
One of Black's biggest problems in the diagram position is that White will get in Qxf3, Qxf4, followed by Qxf7+. With the f7-pawn on g7, Black can shut this plan down with ...g5. It's true putting the f7-pawn on g7 exposes Black's king to Qh5+, but it's not a big deal: Black can meet Qxf3 with ...Qf6, then Qh5+ with ...Kd8 or simply ...g6, and White has no followup. Meanwhile, Black is up a full piece.

# Answer
> 1 votes
In the Muzio proper, White doesn't have a threat other than 6. Qxf4 (which doesn't mean so much, because that's what the c1-bishop wants). Shift the f7-pawn to g7, now White's threatening Qf3-h5+, and that's hard to deal with.

---
Tags: opening, engines, analysis
---


title: Lichess endgame evaluation

text:
# Question
Title: Lichess endgame evaluation
Why is it that Lichess, and other engines for that matter, give a non-zero evaluation score on an endgame position that should be either a draw or a win for one of the sides (given perfect play)? For example, the position below returns an evaluation score of -0.5 when there doesn't seem to be enough material for black to achieve a victory.

```
[FEN "6r1/8/8/8/3k1K2/R2b4/8/8 w - - 0 1"]

```

# Answer
> 10 votes
Unless you explicitly hard-code these endgames, or provide the computer with endgame tablebases, they will apply what they've always done throughout the game: search lines and return the static eval (which is basically the evaluation function of the engine, evaluated on the final position). The static eval isn't smart enough to realize that this game is a draw - keep in mind the static eval is supposed to work for all positions, so it's not surprising that it doesn't return a completely accurate score for this one. Accordingly the computer flatlines at -0.50, until the 50-move rule helps it prune to a draw.

# Answer
> 6 votes
In Lichess, you have 2 separate features: computer analysis and endgame tablebases. Scores are always shown using the computer analysis feature, but at the endgame you can also see the tablebases features, available for 6-men endings I think. If you open this component, you will see each winning/drawing/losing move together with their DTZ (distance to zeroing the 50-moves rule) and DTM (distance to mate).

---
Tags: engines, draw, evaluation, lichess
---


title: Playing Reversed openings

text:
# Question
Title: Playing Reversed openings
In chess games where my opponent is White, White may play 1. e3 or 1. d3, so when I play 1...e5 and 1...d5 in response, I find myself in a reversed opening where I have the opening advantage. What are the advantages to playing like this?

# Answer
> 2 votes
Some reasons I can think of to play this way:

* White player just wants to play with black pieces for whatever reason (just training their black repertoire?)
* White player wants to be sure their opponent don't use an opening book. As far as I know chess opening books (unlike baduk ones) don't have a "symmetry search" feature, so with this trick you just get out of the book from the beginning. Of course White player can use an opening book all the same, but it can become a bit tricky. And of course you can't use the opening book from the chess portal (like the case in lichess).

# Answer
> 5 votes
There's nothing special about this type of position. Play sound, solid chess. Activate your pieces, put your king into safety and occupy the center without overextending. You'll have an easier time than normal achieving an equalized middlegame

# Answer
> 4 votes
Hu.h, that's weird. Your opponent asked the same question earlier. I play 1. e3 and get a reversed French, or 1. g3 and get a reversed King's Indian? What are the advantages in that?

There are none. Grandmaster Larsen used to play 1. a3 to steer for a Reversed Najdorf in the '50s, and while he was glad when it happened, he found it was nothing special.

Your *only* goal in the opening, no matter what you hear here, is to reach a playable middlegame, one with rough equality in center control, development, and king safety. You can get through any opening paying attention to that, and especially while minding the tactics. People think they need to learn openings in order to survive them, but people don't lose in the opening because they're bad at the opening, they lose in the opening because they're bad at tactics.

---
Tags: opening, reversed-openings
---


# Question
Title: Which openings lines are both sharp and drawish?
Two knights defence, Wilkes Barre (Traxler) variation seems to me to be a sharp line which is quite drawish. After the following position:

```
[FEN ""]
[StartPly "15"]

1. e4 e5 2. Nf3 Nc6 3. Bc4 Nf6 4. Ng5 Bc5 5. Nxf7 Bxf2 6. Kxf2 Nxe4 7. Kg1 Qh4 8. g3

```

Black usually continues with 8... Nxg3 and some statistics show that more than 2/3 of the games in this position ended with a draw. I would call this line drawish. But as the same time, it also gives me the impression to be a sharp line (is it not?).

My question is, are there any other lines that are both sharp and drawish?

# Answer
> 6 votes
Typically by *sharp* you mean highly tactical lines, with few alternative moves, where any wrong move leads to immediate defeat.

A sharp **and sound** opening would be one that is so far analyzed that you can claim to lead to more or less equal position.

Many sharp openings tend to be drawish if players know what they are doing. Reasons for that:

* because moves are basically forced, you have a small branching factor and it is possible to analyze such openings much further, sometimes all the way to a perpetual or very drawish endgame
* sharp lines are usually found in open positions, which tend to favour exchanges. The fewer pieces on the board, the more drawish it often gets.

I have a limited repertoire, but I believe there are many lines in the Sicilian which are said to be drawish.

In any case for many mortal chess players this is not an issue as it is unlikely that games are played perfectly through to the draw. Also people at lower level tend to fight for a win playing black and white, so there is not so much of a risk running into a drawish line as white (unles you play a much lower rated player).

# Answer
> 4 votes
A first example of a line that is sharp and drawish is the following variation of the Pirc with f4.

```
[fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
1.e4 d6 2.d4 Nf6 3.Nc3 g6 4.f4 Bg7 5.Nf3 c5 6.Bb5+ Bd7 7.e5 Ng4 8.e6

```

Here are the statistics.

However, the very high percentage of draws is also explained by the fact that some titled players use the next line to make quick draws: 8...fxe6 9.Ng5

```
[fen "rn1qk2r/pp1bp1bp/3pp1p1/1Bp3N1/3P1Pn1/2N5/PPP3PP/R1BQK2R b KQkq - 0 9"]

9...Bxb5 10.Nxe6 Bxd4 11.Nxd8 Bf2 12.Kd2 Be3=

```

---

A second example of a line that is sharp and drawish is found in the following Poisoned Pawn Variation, a line of the Sicilian Defense, Najdorf Variation:

```
[fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]
1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Bg5 e6 7. f4 Qb6 8. Qd2 Qxb2 9. Rb1 Qa3 10. f5 Nc6 11. fxe6 fxe6 12. Nxc6 bxc6 13. Be2 Be7

```

Here are the statistics.

# Answer
> 0 votes
Everything is sharp and also drawish, depending on the inclinations of the players at the moment.

But if the question were 'which opening enables the most flexibility for one player to direct a quiet or a noisy path', then the Petroff. If Black wants to play the Petroff solidly, like Karpov, he can. If Black wants to play the Petroff with abandon, like Marshall, he can.

And it's a pretty big decision for Black following 1. e4 c6 2. d4 d5 3. Nd2 dxe4 4. Nxe4 Nf6 5. Nxf6+. 5...exf6 can be a drawish thing, like Andersson showed. While 5...gxf6 leaves holes all over Black's position, but offers all kinds of dynamic counterplay (Bronstein, Larsen, Seirawan).

---
Tags: opening, two-knights
---


# Question
Title: Listing engine evaluation of each game after opening to track my opening skill level
I've recently picked up the book "Pump up your rating" where the author talks about tracking each of your games with a post-mortem analysis. The report of all your games combined will show you in the long run which areas of your chess game are holding you back.

Inspired by this approach I want to understand which openings I'm playing correctly and which ones I need to study in more detail. I've downloaded my chess games and have tried to analyse them using ChessX, Scid vs Pc and Lucas Chess. Scid vs Pc gives me the option to automatically annotate the games but stores the engine score in a non tabular format. I can only see the evaluation of the moves when opening a specific game.

Ideally I want to add a column to my chess games in a database which shows the engine evaluation of the game at the end of the "Opening".

After some research I found that move 10-12 are commonly accepted as the end of the "Opening". I haven't found a way to programmatically extract the engine evaluation at move 10 or 12 from all my games. Scid vs Pc allows you to add user defined flags but this is just a text string.

I'm very new to chess databases and engines in general and would be greateful for any advice on how to achieve this.

# Answer
> 1 votes
It is good to review games to see why you lost.

Just tracking your alleged 'rating' per some engine after each game is useless as you 'rating' is not that stable until you have a lot of experience and even then there is a wide variation on any given day for most players.

---
Tags: opening, database, scid
---