# Question
Title: How to analyse positions more accurately as a total beginner?
In this position I thought I was winning with white, like +2 or +2.5. But Lichess Analysis shows evaluation as -1.4.

```
[Title "Black to move after Ne5"]
[fen "rn3rk1/1p1b3p/p2n1qp1/3PNp2/P7/1B5P/1PP2PP1/R2QR1K1 w - - 1 0"]

```

The bishop is beautifully placed. The knight will infiltrate. There is a discovered check for me. My rook controls the semi-open file. Black has two undeveloped pieces. There is no immediate pressure on the f-file/f2-pawn.

Why am I worse here? And I would like some general tips for analysing positions as a 1050 chess.com rapid player.

# Answer
> The bishop is beautifully placed.

No, it isn't!

It is semi-bad. There is a chess expression - "Biting on granite". If Black had pawns on f7, e6 and d5 your bishop would be "biting on granite". Your bishop is worse than that. It is biting on something harder than granite, namely your own blockaded pawn.

Now if you had a dark-squared bishop that would be excellent. Just look at all those juicy weak dark squares round the black king. Add to that no black dark squared bishop and if you had one it would be a monster.

> The knight will infiltrate

Really? Where? It is OK where it is. It can be supported by f4 when it will be very difficult to shift.

> There is a discovered check for me

No, there isn't. A competent black is going to keep that useful white pawn on d5 as long as possible, maybe try and win it in the endgame but defintely keep it where it is for the middlegame.

> My rook controls the semi-open file

Again, not true. The "open" refers to pawns not pieces. Controlling a semi-open file means having a rook on a file where you don't have a pawn but your opponent does. It does not mean a rook which is supporting one of your minor pieces on an otherwise completely open file.

> Black has two undeveloped pieces.

And so? What is your practical plan for taking advantage of that? What are you calculations? You don't have any. Black is going to unravel and win unless they are the same standard as you.

> Why am I worse here?

Because you are a piece for two pawns down.

You've just played the mistake Ne5. Why are you moving a piece twice before completing your development? Oh, and Nd4 would have been much better. There your knight really can infiltrate to say e6.

As you say, Black is marginally behind in development. So, you need to complete your development first by moving your queen to connect your rooks, centralize the a1 rook without losing the b2 pawn and only then launch your attack.

> And I would like some general tips for analysing positions as a 1050 chess.com rapid player.

Do two things:

1. Complete your own development before going on the attack
2. Try and work out what your opponent's plans are (or should be) and try and stop them.

One other thing. Sacrificing a piece for two pawns and a check is a very common way of losing games at lower levels. At your level just don't sacrifice until your tactical awareness is much better and you have a reasonable chance of calculating what is going to happen next.
> 14 votes

# Answer
Most of what you said is true, but at the same time Black is up a knight for two pawns. This is a significant material advantage, and White's compensation isn't enough to balance the scales. He has active pieces yes, but his activity is nowhere near decisive. Black should manage to untangle and develop his queenside before White can muster enough of an attack.
> 10 votes

# Answer
1. Include the positional strengths of you opponent in your evaluation. For example Knight on d6 is nicely blockading your d-pawn.
2. How will you take advantage of your well placed pieces? What is the plan? A good looking piece with nothing to do is not much advantage.
3. Is your Bishop beautifully placed? It has limited action and is blocked by your d-pawn. How will you unblock it? c2-c4-c5?
4. Unless you are a computer I suggest not using number evaluations.
5. Include dynamic evaluation as well as static evaluation. What are the plans for each side?
> 3 votes

# Answer
1. First and foremost, white is down material with no immediate prospects of attack.
2. The black knight perfectly and eternally blockades the pawn, leaving the white bishop to hopelessly eye a king that it will never influence. How will white remove the knight? c4-c5 may be stopped with b6. (Though there is admittedly a prophylactic a5 by white to stop b6.) Trading white's last remaining knight for the knight is fruitless -- particularly since black may replace it with another piece such as... the other knight! If it ever seems truly necessary, black may simply oppose the light-squared diagonal via Bf7. Or even just play Kh8.
3. Black also lacks accessible *weaknesses and targets*. It is not sufficient to have "well-placed" pieces if they do not fulfill any concrete roles in exploiting weaknesses.
> 3 votes

# Answer
I agree with your evaluation that positionally, white is better. In fact, when I looked at the position, my instinct told me within 1 second that White has a beautiful position. But why is Black better? On closer inspection, I realised that you are down a piece.

In any position where you are down material but the position is unclear, to arrive at an evaluation, you should ask yourself whether you have sufficient compensation for the material. You clearly have *some* compensation --- you would be much better if black were not up a piece, but is this enough? Well, after Ne5, Black is not immediately getting mated by any means, so it is very natural to move the bishop and then play Nd7 to trade off your powerful knight. You get nothing concrete, and if that's the case, you're just down a piece and losing.

On the other hand, consider the position before Ne5:

```
[Title "White to move"]
[fen "rn3rk1/1p1b3p/p2n1qp1/3P1p2/P7/1B3N1P/1PP2PP1/R2QR1K1 w - - 0 1"]

```

In this position, you have to play more forcefully and concretely in order to justify an advantage, given that you are down material. Ne5 is bad for this reason, because it is too slow and allows black to untangle. Instead, it is important to activate your bishop on b3 through the idea of c4-c5.

Concretely, the best move accoridng to Stockfish 15 NNUE is 1.a5. How in the world would you come up with such a move? Actually, it's easy. Let's calculate some concrete lines: if 1.c4, the threat is c5, so black's most natural response is 1...b6. Starting with 1.a5 first at least prevents this idea. Although, things are not quite so simple because black also has Ne4 and some complications... it is, honestly, not easy to evaluate this position without given a lot of time on the clock. The best takeaway here, I think, is simply the idea that **you must play forcefully and concretely to recover compensation for the piece**. Ne5 is too slow for this reason. 1.a5 might seem slow, but it has the concrete threat of c4 c5 if black doesn't find Ne4, for example, not to mention in the long term it positionally restricts black (e.g. in all endgames b7 is weak).
> 2 votes

# Answer
It has been well said that chess games are not won by creating good positions but by making good moves. Every comment by the OP about the position is true in a way. It describes the potential in the position but does not consider the moves needed to realise that potential. For the reasons given by Yifan, this position is entirely about the battle to play c5, although this is not immediately obvious. But that move is so strong that it is worth considering even such a slow move as Ba2, to enable b4 after first playing a5. I am not saying that Ba2 is good, just that there are good reasons to consider it. If it should turn out to be good, an annotator would be justified in calling it "deep". Generously, let us suppose that the missing White Knight was a deliberate sacrifice. Could it have been made by a strong aggressive player? I think it could, but only if that player had not only seen the potential in the position, but had felt confidence that they would be able to find enough resources to unlock that potential. Can the good position be made even better?Tal might perhaps have felt that confidence. Lacking his genius, I must call the position unclear.
> 1 votes

---
Tags: analysis, beginner, evaluation
---


# Question
Title: Why is this position judged to be so balanced, and why is castling wrong?
For the position after 10...Kc4:

```
    [Title "White to move; castling is considered a blunder"]
    [FEN ""]
    [Startply "20"]

    1. e4 e5 2. Nc3 Nf6 3. Nf3 Bb4 4. Bc4 Bxc3 5. Bxf7+ Kxf7 6. bxc3 Nxe4 7. Nxe5+ Kf6 8. Qf3+ Kxe5 9. d4+ Kd5 10. Qf5+ Kc4 11. O-O? d5 12. f3 Bxf5 13. fxe4 Bxe4

```

The position from a blitz game I just played; I was Black.

I'm up 5 points of material, but obviously my King is horrifically exposed.

Stockfish rates the position after 10...Kc4 as drawn, which seems surprising given the lack of any immediately obvious threats.

But if White castles with 11.0-0, then the position immediately drops to -5.67. I can only assume that Stockfish believes it can see a series of forced attacks by White which ultimately end in a draw, but dropping tempo at any point allows Black to "escape."

But a) I'm not sure that I've got that right. And b) I can't really tell how it's supposed to work if that is right.

# Answer
This is a classic case of king safety vs. material balance. Black's king is obviously way less safe than white's, BUT black has a lot more material. So if black manages to survive and consolidate their position, then black will win.

Castling is not a very direct move in this position, and the simplest explanation why it's bad is that it's too slow, allowing black to bring their king to safety by means of playing ...d5 followed by ...Kb5 and then letting the black king slowly creep towards a safe haven surrounded by friendly pieces. This shouldn't come as a great surprise; after all, you gotta strike while the iron is still hot!

The thing that genuninely surprised me about your post was your comment that Stockfish rates the position as drawn. I get different results when running SF on my machine, as it's convinced that white is just winning after trying to immediately kill the black king with Rb1 (threatening Qb5+, with mate soon to follow).

The winning line goes as follows, and I don't see any flaw in it: **11. Rb1!** (cutting off black's king's escape route via b5) **11...c5 12. Qf7+** (forcing black to block its king's mobility further) **12...d5 13.Qf3** (threatening checkmate in 1) **13...cxd4 14.Ba3!** (cutting off black's king's escape route via c5) **14...Nxf2 15.0-0** (here castling is actually a good move, as it moves white's king out of the way of some annoying knight checks) **15...Rf8** (if black starts giving back material, then black might as well resign on the spot as nothing in the position speaks in black's favour then) **16.Qe2+ d3 17.cxd3 Nxd3** (here we see the point of castling more clearly; if white's king were still on e1, ...Nxd3 would be check, which could give black some time to consolidate) **18. Rfd1!** (threatening checkmate in 1) **18...Bf5 19. Qc2!** (threatening checkmate in 1; here black is finally forced to give up massive amounts of material just to delay the inevitable), and white is completely winning. Go through this line carefully (it's quite a good example of how to conduct a proper king hunt), and note how at every move white harasses the black king trying to checkmate it. This leads to black not having time to coordinate their pieces properly, and their king gets caught in an inescapable mating net at the end. This is why in this position (and many, many others as well) king safety trumps material count.
> 12 votes

---
Tags: analysis
---


# Question
Title: Open problems in chess involving maximum material imbalances
I am posting the present question since here Very unbalanced Chess Positions I have introduced three open problems (i.e., the third one, the fourth one, and the sixth one from the above), regarding maximum material imbalances reachable in final chess positions, that still remain unsolved.

In details, we assume by hypothesis that
Pawn := (P) = 1 point;
Knight := (N) = 3 points;
Bishop := (B) = 3 points;
Rook := (R) = 5 points;
Queen := (Q) = 9 points;
King := (K) = 0 points.

Then, let me quote that "A stalemate occurs when the player on move is not able to perform any legal move, and at the same time is not threatened by check. Thus, stalemate can be forced by both players" (i.e., we can face only two possible stalemate scenarios, white stalemated or black stalemated).

Now, under the standard FIDE rules, our three goals (unsolved problems by ) are as follows:

**First open problem:** Which is the maximum difference between the "total score of White" minus the "total score of Black" that black can force by playing a move that results in **white stalemated**?

**Proven lower bound** for First open problem is **81**, that is achieved through the following play:

```
[fen ""]

1.  g4 f5 2.  gxf5 g5 3.  h4 g4 4.  h5 Kf7 5.  f6 Ke6 6.  fxe7 Kf6 7.  e8=Q g3 8.  Nf3 g2 9.  Rh4 g1=B 10.  a4 b5 11.  axb5 a6 12.  bxa6 Bb7 13.  axb7 Nc6 14.  bxa8=Q Qe7 15.  Qeb8 Qd6 16.  e4 Kg7 17.  e5 Qd5 18.  e6 Qe5+ 19.  Qe2 Qf6 20.  exd7 Qf7 21.  d8=Q Nce7 22.  Qdxc7 Nf6 23.  Qea6 Nfd5 24.  Qac8 Nf6 25.  Ne5 Ned5 26.  f4 Kg8 27.  Nc6 Ng4 28.  c4 Ne5 29.  fxe5 Qf6 30.  e6 Qf7 31.  e7 Qf6 32.  e8=Q Qf7 33.  Nd4 Qe7+ 34.  Kd1 Qf7 35.  Qea4 Qg7 36.  Q4a7 Qf7 37.  c5 Qe6 38.  Qd6 Qe7 39.  c6 Qf7 40.  c7 Qe7 41.  Qcb7 Qf7 42.  c8=Q Qe7 43.  Qdc7 Qf7 44.  Nf5 Nf6 45.  d4 Ne4 46.  d5 B1c5 47.  Ne7+ Kg7 48.  Bg5 Qg6 49.  Nc6+ Qf7 50.  Bd8 Nf6 51.  Re4 Nd7 52.  Re7 Kg8 53.  Rxd7 Kg7 54.  Ne7 Bb4 55.  Ra6 Ba3 56.  Rb6 Bc5 57.  Ba6 Ba3 58.  b4 Bb2 59.  b5 Ba3 60.  Nd2 Bb4 61.  Nb3 Qe6 62.  h6+ Kf7 63.  Kc2 Rg8 64.  Kd3 Rg7 65.  hxg7 Kf6 66.  g8=Q Ba3 67.  Qg1 h5 68.  Qgc5 h4 69.  Q5c6 Kf7 70.  Kd4 Qh6 71.  Nc5 Qf4+ 72.  Qxf4+ Kg7 73.  Qfd6 h3 74.  Qf4 h2 75.  Qxh2 Kf7 76.  Qhc7 Kg7 77.  Ke5 Kf7 78.  Kd6 Kf6 (1/2, 1/2).

```

**Second open problem:** Which is the maximum total value of the white pieces on the board that can be achieved by playing a regular FIDE chess game that ends with **white stalemated**?

**Proven lower bound** for Second open problem is **91**, that is achieved through the following play:

```
[fen ""]

1.  g4 f5 2.  gxf5 g5 3.  a4 b5 4.  axb5 a6 5.  bxa6 Bb7 6.  axb7 g4 7.  bxa8=Q g3 8.  Nf3 c6 9.  h4 g2 10.  h5 h6 11.  c4 d5 12.  cxd5 g1=B 13.  dxc6 Kf7 14.  c7 Qd7 15.  cxb8=Q Qd8 16.  d4 Qd7 17.  Bxh6 Bg7 18.  Bg5 e6 19.  Qc2 Rh6 20.  Qcc8 Rg6 21.  d5 Qe7 22.  d6 Qf6 23.  d7 Qe5 24.  d8=Q Qf6 25.  Qda5 Qe5 26.  Q5a7+ Qc7 27.  Bd8 Rg5 28.  h6 Rg6 29.  h7 Rg5 30.  h8=Q Rg6 31.  e4 Rg5 32.  Ba6 Bf8 33.  Qh2 Qe7 34.  Qhc7 Kg7 35.  fxe6 Qf7 36.  e7 Qf6 37.  e8=Q+ Qf7 38.  Nfd2 Rg6 39.  f4 Rg2 40.  e5 Rg6 41.  e6 Rg5 42.  Qeb5 Rg6 43.  Q5b7 Rg4 44.  e7 Nf6 45.  e8=Q Nd5 46.  Rh6 Nb6 47.  Rxb6 Rg6 48.  Qec6 Qd7 49.  f5 Kh6 50.  f6 Kg5 51.  f7+ Kg4 52.  Nc3 Bg7 53.  f8=R Rf6 54.  Re8 Kg5 55.  Rd1 Bc5 56.  Nde4+ Kf5 57.  Rxd7 Ba3 58.  b4 Bf8 59.  Kd2 Kg4 60.  Kd3 Kf5 61.  Kd4 Kg4 62.  Kd5 Kf5 63.  Ree7 Kg4 64.  Nc5 Rf1 65.  Kd6 Rd1+ 66.  Nd5 Kf5 67.  b5 Rd2 (1/2, 1/2).

```

**Third open problem:** Which is the maximum value of White pieces plus Black pieces on the board that is achievable by ending the game in (white or black) stalemate (i.e., a generic stalemate ending a playable chess game and nothing else)?

**Proven bound** for Third open problem is given by the interval **\[168, 180\]** (i.e., the maximum value of all the pieces on the board, adding the pieces of both players, belongs to the set {168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180}), since the following game could be played:

```
[fen ""]

1.  a4 b5 2.  axb5 c5 3.  d4 c4 4.  Bd2 c3 5.  d5 Nc6 6.  dxc6 Ba6 7.  b6 d5 8.  b7 f5 9.  Bf4 h5 10.  Bd6 exd6 11.  Nd2 g5 12.  b8=Q Rh7 13.  f4 cxd2+ 14.  Kf2 Rd7 15.  c7 d4 16.  e4 d3 17.  Qe2 d5 18.  c8=Q d4 19.  b4 Kf7 20.  b5 Kg6 21.  b6 Nf6 22.  b7 Nd5 23.  Qbc7 Nb4 24.  b8=Q d1=Q 25.  e5 d2 26.  e6 d3 27.  e7 Qb1 28.  e8=Q+ Kf6 29.  c4 d1=Q 30.  c5 d2 31.  c6 Qdb3 32.  h3 Bb7 33.  Qa5 Rd5 34.  c7 Qe7 35.  Qcd8 Re5 36.  c8=Q Bd5 37.  Qdb6+ Re6 38.  Q2b5 d1=Q 39.  Qb8b7 Nc6 40.  fxg5+ Ke5 41.  g6 f4 42.  g4 Qd6 43.  g5 Qba3 44.  Be2 Qdb3 45.  Bg4 hxg4 46.  g7 f3 47.  g8=Q Q1a2+ 48.  Kg3 f2+ 49.  Kh2 Qdb4 50.  Ne2 f1=Q 51.  Rc1 Nd4 52.  h4 Rb8 53.  Rc7 Qfa1 54.  h5 g3+ 55.  Kh3 g2+ 56.  Kh4 g1=Q 57.  h6 Qgb1 58.  h7 Qb3b2 59.  g6 Ke4 60.  h8=Q Nb3 61.  Qbd7 Bh6 62.  g7 Bc1 63.  Qgf8 Nd2 64.  g8=Q Q4b3 65.  Qac5 Kd3 66.  Ng3 Re4+ 67.  Qdg4 Rc4 68.  Qed8 Rc2 69.  Qde8 Bc4 70.  Qhh7+ Kc3 71.  Qbe6 a5 72.  Qba6 a4 73.  Qaa5+ Rb4 74.  Qe1 (1/2, 1/2).

```

I have found the given bounds by performing "manual" calculations only, but it would be fantastic to have a program to do this kind of stuff by evaluating millions of positions.

# Answer
> 1 votes
I think that these positions may be new, and push the boundaries of what has been done. They are better than anything I have seen.

On the other hand, the notion of manual mathematical proof for chess problems in general and constructions in particular can be difficult, case-based and tedious. And I don't see any software emerging for this kind of thing.

What often happens is that someone may see a composition, and because they are not coming from the same mental place, find a way to improve it. And so it goes on. If a long times passes with no improvement, maybe one can be a bit more confident that it's the best.

I have posted these three positions in PDB, so other chess problem enthusiasts may have a chance to see, and maybe improve. https://pdb.dieschwalbe.de/search.jsp?expression=a%3D%27rip%27+and+k%3D%27const%27

---
Tags: problems, records, mathematics, retrograde-analysis, dead-position
---


# Question
Title: When is it a good idea to trade pieces in the endgame?
Per title, I'm wondering when it's a good idea when defending an inferior endgame to seek to trade pieces, and when not to do it.

For example, take this endgame with Black to play:

```
[FEN "1k2q3/1pp1r3/p2p2p1/P2P3p/5P1P/1PQ3P1/2P5/1K1R4 w - - 3 30"]

```

With the extra pawn White's position is clearly preferable, but it's not obvious how to make progress, so Black has realistic chances of holding. As Black, is it a good idea to:

* Trade queens?
* Trade rooks?
* Neither, keep all the pieces on the board?

The pure pawn ending is lost, so Black clearly has to keep some pieces on the board to threaten counterplay with. However, which pieces? If Black wants to trade rooks then 1...Re3 forcing 2. Rd3 achieves the trade, but is it a good idea?

# Answer
General rule: If losing, trade pawns. If winning, trade officers.

Specific rules, as always in chess:

* Black controls the only open line - big time. One argument more for not trading.
* Both kings are relative safe, but as White, after e.g. 1...Re3 2.Rd3 Re1+ 3.Kb2 Qe2 with the idea of doubling on the first, I already would have a certain Halloween feeling :-) (You can't scare an engine, though: +1) Still an argument against trading. White can't produce any mating scare at all.
* A sketchy analysis confirms that +1 increases to +1.5 after trading either rooks or queens. If queens remain, White must safeguard against a perpetual to bring home the bacon. If rooks remain, White must activate the rook (by bringing the king into the center and offering a trade). None of this is a trivial win, rooks might be a bit easier.
* Trading both officers, even by ruining the pawn structure with cxd3, increases the white advantage to +2.
> 9 votes

---
Tags: endgame, trading
---


# Question
Title: Can a grandmaster still win against engines if they have a really long consideration time?
Can a grandmaster still win against engines if they have a really long consideration time? For example, say that Stockfish gets 20 minutes and the GM receives days, if not weeks.

# Answer
> 17 votes
Are there asymmetric time controls where a GM can still beat Stockfish? Certainly, as long as you give Stockfish little enough time. I think the time you give to Stockfish is almost more important than the time that the GM gets. At 20ms I would favor the GM even at tournament time controls.

A few years back I played a handicap game against Komodo where I played some blitz time control (maybe 5+0 or so, I don't quite remember) and Komodo had 1 second, which should work out to roughly 20 ms per move and I think back then I could actually win that game. Since then engines have progressed so modern Stockfish is probably 300 rating points stronger than the Komodo from back then, but on the other hand I am more than 300 rating points below a GM so I would think the GM should have chances even if they blitz, nevermind at tournament time controls or longer. As it turns out engines aren't really made for 20 ms per move games so they don't perform very well there. Now if you give the engine a second per move things may be very different.

As a fun experiment you can just try yourself, give yourself sufficiently much time against Stockfish and give it a go, see how it goes.

# Answer
> 13 votes
Here's a comment by GM Kaufman, developer of Komodo (emphasis mine).

> Q: Author Cyrus Lakdawala suggested I ask: In what respect are the program's move choices human?
>
> A: All the features of the engines' evaluation function have been based on how some human (in the case of Komodo, me) thinks they should be defined. The weights were originally my subjective ones, but gradually got "tuned" by testing and automated methods. So in theory, if the search depth were the same as mine (which of course is variable so this is unrealistic) it should play somewhat like I do, although I don't add up hundreds of numbers in my head when I play, I just estimate everything. The main reason Komodo is a thousand or more Elo stronger than I am is that it searches so much further ahead in nearly every line than I could possibly do. **Perhaps if I spent 24 hours per move on a game (moving pieces around freely, but not consulting any engine) I could play as well as Komodo plays a blitz game, but that's just a guess.** Note that this does not apply to NN engines, which (in pure form) don't have any human knowledge input.

So: maybe.

# Answer
> 1 votes
The computer's big advantage is its speed. It can look at millions of possibilities in seconds. But the human Grandmaster would have the advantage of being more selective and knowing just what variations to concentrate on. Based upon that, I would think that given unlimited time, a Grandmaster would be able to defeat the machine under the conditions you stipulate, its speed notwithstanding.

# Answer
> 1 votes
The short answer is yes, but there's more to it. For one thing the usefulness of the consideration time stockfish gets is dependent of the computer it's run on. On my phone stockfish takes some time to compute 100m nodes (each node being a potential position or board), on my pc it takes a few seconds to generate that amount of nodes. Also 20 minutes is almost certainly still going to be more consideration time than stockfish 15 needs to beat any human even just being run on a phone. Stockfish would probably have to be limited to a very small amount of time or a relatively small number of nodes before it becomes beatable by any human, but given a small enough limit it *will* become beatable.

---
Tags: engines, grandmaster, time-management, super-grandmaster
---


title: What unusual engines do we have?

text:
# Question
Title: What unusual engines do we have?
Almost all current engines are similar and built for the same tasks (stockfish, lc0, slowchess, comodo...). And I only heard about a few unusual engines

Crystal: based on Stockfish but used for problem solving

SimpleEval: as I know also built on Stockfish, uses only material counting (1, 3, 3, 5, 9) as evaluation

Boris-Trapsky: plays not the strongest position, but position in which a person is likely to make a mistake

Maia: try to play like human

There are also different game modes in Komodo, but they are not free.

From serious and large projects, I heard only about this. I would like to know if there are similar engines, it is not necessary that the engine plays very well or was created by a large company, the main thing is that it is not ordinary.

# Answer
> 2 votes
Dr Tom Murphy examines 30 interesting chess algorithms in a joke paper for SIGBOVIK 2019, which can be read here:

http://tom7.org/chess/weak.pdf

Among them are strategies such as:

* "worstfish", which plays the worst move according to Stockfish
* Various neural networks strategies, some of which are given modified views of the board
* A strategy that plays the move that minimises the number of resulting legal moves for the opponent
* "equalizer", which prefers to move pieces that have been moved the fewest times
* Less popular classical chess engines such as Topple and ChessMaster for the NES

A video version of the paper is also available: https://www.youtube.com/watch?v=DpXy041BIlA

# Answer
> 3 votes
One that is different is CorChess. CorChess was designed having correspondence chess in mind. Later it has been adapted to be competitive in any kind of time control. It is 100% free. Here is the link: https://chess.massimilianogoi.com/download/corchess/

Lichess uses Stockfish, but something interesting is that level 1 makes mistakes on purpose. So, it is like a Stockfish reversed! People who just learned the rules of chess can defeat it! In the following link, you need to select play against the computer, and then select level 1: https://lichess.org/

About your comment that all engines are equal... I am not an expert, but as far as I know Stockfish tries to search and calculate all the possibilities but Leela Chess Zero (LC0) uses a different system, using probabilities and neural networks.

If you love to learn more about chess engines, my favorite website is https://chessengines.blogspot.com/

They also have a weekly free magazine that I highly recommend to you.

P.S. Even though the last version of Komodo is not free, they have been sharing previous versions for free. At this time, the latest version that is free is Komodo 13. You can download it here: https://komodochess.com/

---
Tags: engines, programming, computer-chess
---


# Question
Title: What is the deepest Stockfish evaluation of the standard initial position that has ever been done?
Letting Stockfish (14+ NNUE) run for several minutes with lichess' analysis tool on the initial position of a standard chess board lets it reach depths beyond 30 moves, I suppose letting it run for many hours or days would result in an even deeper evaluation.

What is the deepest evaluation ever done of this kind?

# Answer
> 22 votes
In the chessbase cloud, this depth 79 evaluation is displayed:

Which means someone used Chessbase to get their Stockfish 12 engine to calculate to depth 79, and they had an internet connection at the time so it was able to be stored on the cloud. However, there are some caveats:

1. We don't know the engine settings that this person was using -- although I doubt this matters much though for the calculation time required, relatively speaking.
2. There could have been a deeper search done by someone, who either wasn't connected to the cloud at the time, or maybe wasn't even using Chessbase at all.
3. Chessbase might have an even higher depth evaluation stored in its cloud for Stockfish, but they just choose to show this depth 79 one (I don't know how this works).

But all in all, depth 79 seems like a good ballpark at the very least.

Also as @TonyK mentioned, Stockfish depth is in plies (so depth 79 refers to roughly 40 moves). Also Stockfish does very aggressive pruning. An exhaustive depth 79 search would involve something on the order of 30^79 nodes.

# Answer
> 16 votes
Don't for one minute imagine that Stockfish has analysed all lines out to 30 plies (yes, that's plies, not moves). It has analysed *some* lines up to 30 plies, but most lines have been discarded well below that depth as being unproductive. Occasionally it will erroneously discard productive lines, but Stockfish being Stockfish, this doesn't happen very often.

---
Tags: engines, analysis, solving
---


title: Detecting traps in chess

text:
# Question
Title: Detecting traps in chess
Are there any ways to detect if the opponent is setting a trap, without explicitly just "knowing" the position?

# Answer
The most important thing to have is a sense of tactical danger, and this comes about as a combination of tactical intuition, and calculation ability. Intuition comes from playing *lots* of games, winning about half and losing about half --- from the losses, many of those will be from tactical blunders, which will train your brain emotionally to be averse to such blunders, and eventually it enters your subconscious and becomes intuition. Calculation ability can be trained by similarly playing lots of games, but also specific tactical training e.g. solving puzzles, analysing complicated middlegame positions or solving studies, etc.

Concretely, it is helpful to be aware of the idea of "compensation". If your opponent is giving away pawns or pieces in the opening, you should always be on high alert and ask yourself: did they just blunder that, or do they have a plan? If they have a follow-up plan, is it good? This follow-up might be in the form of a 1-move tactic that wins back the material, or it might be some kind of "long term compensation", meaning e.g. a strong mating attack.

```
    [title ""]
    [fen ""]

    1.e4 e5 2.Nf3 Nc6 3. Nc3 Nf6 4. Bc4 Nxe4

```

This is a mild example of a "trap" that happens very often in beginner games, where 4.Bc4 is already an inaccuracy because of 4...Nxe4 seemingly giving up a piece. The "trap" is that after 5. Nxe4, black has 5...d5 to win back the piece, and black is already equal and white is not better. So, if you have a good sense of tactical danger, you will know to avoid this "center fork trick" and not play 4.Bc4. (This line is playable, and apparently has even been played by Wesley So in a rapid game, but it is really not good for White.)

But even more serious are the traps that lead to a losing position for one side.

```
    [title ""]
    [fen ""]
    1. d4 e5 2. dxe5 Nc6 3. Nf3 Qe7 4. Bf4 Qb4+ 5. Bd2 Qxb2 6. Bc3 Bb4 7. Qd2 Bxc3 8. Qxc3 Qc1#

```

For example there is this famous trap in the Englund gambit. How to avoid falling for such things? Well, you should first notice as White the existence of the forcing move Qb4+ forking the bishop and the pawn on b2. (A lot of people at beginner level would play a move like 5.Nbd2 hanging the bishop.) Then, you should notice that 6.Nc3 is the only move, because this line with 6...Bb4 is losing, given the pin to your king.

There is obviously no one size fits all solution to never ever fall into an opening trap again. Famously, GM Elshan Moradiabadi lost in 10 moves against GM Lenier Dominguez Perez in the US Championships 2022!

```
[title "Dominguez vs Moradiabadi, US Champs 2022"]
[fen ""]
1. e4 e5 2. Nf3 Nf6 3. Nxe5 d6 4. Nf3 Nxe4 5. d4 d5 6. Bd3 Be7 7. O-O Bf5
8. c4 O-O 9. cxd5 Qxd5 10. Bxe4 1-0

```

The big mistake was 8...O-O and the game was well and truly lost after 9...Qxd5. Black resigned because Re1 is coming to pick up the hanging bishop on e7, either on the next move if Qxe4, or two moves later after Nc3, queen moves, and Nxe4.

The only advice that can be given is to strengthen your tactical sense of danger, so that you are more aware to traps like these. Another point is to simply keep playing chess, and after thousands of painful losses, you will eventually learn so many traps that you are unlikely to fall into those again. Once you're strong enough, maybe 2000+, it could be worth the energy to invest time into studying openings specifically as well, which will further improve your opening play so you don't lose to such traps again. However, as we have seen from the previous example, you will never stop making blunders, you can only seek to decrease their frequency. :)
> 3 votes

# Answer
You might not have alluded to Possibility B, but I add it for completeness: If you know the opponent good enough, you can scan for "Poker tells".

I give no warranties though, as this little story proves:

I played a dude in the chess club. Selfsame dude was...well, a certified jerk. Pet theory: The more jerkish you are, the better you can "read" the opponent (evolution at work). I was the stronger player, but I stood abysmal and tried a last trap: Played my move and *ohbotherthatwasalousyoneimsuchapatzer*-ed. He looked into the position - man, what a lame trap. Of course he immediately looked through my body language and played another move.

Which was actually far worse than accepting the "trap", which would have royally backfired if calculating a bit deeper. Or in one word:
> 1 votes

---
Tags: analysis, opening-traps
---


# Question
Title: History of this queen sacrifice in the 4 Knights
Arbiting an IM norm tournament last week I came across this position in one of the games. Both White's queen and bishop on a4 were en prise and it was Black's move!

My initial reaction was that I must have missed a touch-move violation which the players had sorted out themselves. Next I wondered why White hadn't just resigned. Finally, when I saw that Black was deep in thought, I wondered why he didn't just whip the queen off immediately.

```
[Title "Jonah Willow vs Neil Berry 4th EJCOA IM 2022"]
[fen ""]
[Startply "19"]

1. Nc3 Nf6 2. e4 e5 3. Nf3 Nc6 4. Bb5 Nd4 5. Ba4 c6 6. Nxe5 d6 7. Nf3 Bg4 8. d3 Bh5 9. Rg1 b5 10. Nxd4 Bxd1 11. Nxc6 Qc8 12. Bxb5 Nd7 13. Kxd1 Qb7 14. Be3 Be7 15. e5 a6 16. Ba4 Bd8 17. Ne4 O-O 18. Nxd6 Qxb2 19. Bd4 Qa3 20. Bb3 Nxe5 21. Bxe5 Qc5 22. Ba4 Qxf2 23. Bd4 Qf4 24. Ne4 f5 25. Nd2 Bf6 26. Nf3 Bxd4 27. Ncxd4 Qd6 28. Re1 Kh8 29. Rb1 Rab8 30. Rxb8 Rxb8 31. Bb3 g6 32. Re6 Qf4 33. g3 Qg4 34. Kd2 Rd8 35. Kc3 Rc8+ 36. Bc4 Qh3 37. Re7 Qh5 38. Ne5 Rb8 39. Ndf3 f4 40. g4 1-0

```

As you can see, White went on to win. Overhearing the postmortem, Qc8 was a mistake. Qd7! would have been better and, according to the white player, the computer gives a long line ending with an evaluation of 0.00. Quite remarkable.

What is the history of this stunning queen sacrifice?

# Answer
> 10 votes
Seems to be a relatively unknown sacrifice - the chessbase online database gives me three games after 10.Nxd4, all of which were correspondence and within the last decade. The root game is M.Dos Santos-A.Dutra, correspondence 2014. So it appears the game you mentioned will be the first OTB game featuring this sacrifice.

Somewhat interestingly, none of the moves after 4.Bb5 are rare themselves - they are all either the most common or second most common choice. The second most popular moves are: 4...Nd4, 5...c6, 8...Bh5, 9.Rg1, and 10.Nxd4.

---
Tags: opening, history, sacrifice, four-knights, queen-sacrifice
---


title: Mac Desktop Client for FICS

text:
# Question
Title: Mac Desktop Client for FICS
What are good chess clients for Mac, that allow playing on FICS. Nice-to-haves are an opening book, plug-and-play engines, and scoring of chess positions.

EDIT: For completeness, note that Jin does not allow you to save games. FICS can email them to you if you turn on a setting, but no way to recover guest games with Jin. I think this is a complete deal breaker.

# Answer
You have choices:

i. Kibitz, implemented features are

* Playing and observing chess games on FICS
* Observing multiple games
* Chat with other users on FICS
* Support for chess variants including "Bughouse" and "Crazyhouse"

ii. Raptor, FICS desktop client for Mac

iii. Jin, which is Java based and can be executed on a Mac also.

iv. XBoard, a multi platform solution!

and such a pity that you can't try BabasChess (maybe you can use a emulator to execute it on your Mac)
> 2 votes

# Answer
When I switched to OSX I noticed that Babaschess would not run. Since I am a developer I started creating my own client.. Please, have a look and let me know what you think. It doesn't support chess engines to analyze positions, but saves your games as pgn.

http://www.macbeth-ficsclient.com/
> 1 votes

# Answer
If you want something very simple to start with, try LightFICS: http://lightfics.brrm.ru/

It's a native Mac OS X FICS client. It has no dependencies, is extremely easy to install and use. It doesn't have any nice-to-haves, but you can save games as PGN and use other tools to analyse openings with engines.
> 1 votes

# Answer
I don't have a mac, and i'm not a FICS user, here's what i found by googliing

http://sourceforge.net/projects/kibitz.berlios/

http://chesshive.com/2011/08/raptor-chess-fics-desktop-client-for-mac/

http://www.reddit.com/r/chess/comments/18kbm9/what\_software\_do\_you\_use\_with\_fics\_on\_mac\_osx/

http://www.chesscircle.net/forums/showthread.php?2420-Macintosh-ICC-FICS-client
> 0 votes

# Answer
ChessX is phenomenal. I can confirm it works under Mac OS Ventura:

https://chessx.sourceforge.io
> 0 votes

---
Tags: macos
---


# Question
Title: What's a line for black in the Sicilian that has good piece activity?
I'm looking to learn the Sicilian for black. There seem to be a hundred different variations. It's easy enough to look them up, but it's hard to get a feel for what kind of games they lead to.

Can anyone recommend a line in the Sicilian that leads to somewhat open positions, with lots of piece activity, and doesn't tend to lead to lots of trades?

# Answer
> 3 votes
Broadly speaking, the Najdorf and Sveshnikov are probably the best, as far as getting an active game while being objectively sound. Another option is the Dragon, which is often even sharper (while somehow having less theory than the aforementioned two). However, the downside is that objectively, White should be pressing a little. The Dragon's still in better theoretical standing than a number of other Sicilians though, it's just not quite on the level of the Najdorf and Sveshnikov.

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


# Question
Title: Can white survive from this position that Stockfish rates even but where every line seems to lose?
I played this game against Stockfish level 4. I am not a good player. I reached a complex midgame and blundered with 34. Qf3, swiftly losing thereafter.

Depicted below is the position just prior to the blunder, which Stockfish rates as exactly even. However, every line I try from here, including Stockfish's suggestions, inevitably leads to a black win. Can white survive from this position and if so, how?

```
[fen ""]
[StartPly "66"]

1. e4 c6 2. d4 d5 3. e5 Bf5 4. Nf3 e6 5. c3 c5 6. Bb5+ Nc6 7. Qa4 Qc8 8. b3 h5 9. Bf4 h4 10. h3 Ne7 11. g4 Bg6 12. Bg5 Ng8 13. Nxh4 Bh7 14. Nd2 f6 15. Bf4 g5 16. Bxg5 fxg5 17. Nhf3 Be7 18. c4 Kf8 19. cxd5 exd5 20. Rc1 Kg7 21. dxc5 a5 22. h4 Nf6 23. hxg5 Nxg4 24. Rh4 Ncxe5 25. Nxe5 Nxe5 26. Qd4 Qe6 27. Be2 Bxg5 28. Rh5 Qf6 29. Qxd5 Rad8 30. Qxb7+ Rd7 31. Qg2 Nd3+ 32. Bxd3 Bxd3 33. Rxg5+ Kf7 34. Qf3??? Re7+ 35. Kd1 Be2+ 36. Qxe2 Rh1+ 37. Kc2 Rxc1+ 38. Kxc1 Qa1+ 39. Nb1 Rxe2 40. c6 Qb2+ 41. Kd1 Qc2#

```

# Answer
> 10 votes
The reason why Stockfish gives this as 0.0 is because of the following engine line that ends in a perpetual.

```
[Title ""]
[FEN "7r/3r1k2/5q2/p1P3R1/8/1P1b4/P2N1PQ1/2R1K3 w - - 0 1"]

1. Rg3 Bb5 2. c6 Rxd2 3. Rg7+ Kf8 4. Kxd2 Qd4+ 5. Ke1 Qb4+ 6. Kd1 Qd4+ 7. Ke1 Qd3 8. Re7 Kxe7 9. Qg7+ Ke6 10. Qg4+ Ke5 11. Qg7+ Ke6 12. Qg4+ Kf6 13. Qf4+ Ke7 14. Qe5+ Kf7 15. Qf4+ Ke8 16. Qb8+ Kf7 17. Qf4+

```

This is quite difficult to find for a human, I think, because of the moves 3.Rg7+ and 8.Re7, seemingly hanging the rook on both occasions. Nevertheless, these moves seem to draw the game according to the engine due to the vulnerability of the black king to checks. Note that black cannot play a move like 10...Qf5 to stop the perpetual because in that line white takes the queen followed by Rc5+, picking up the bishop, and white actually wins.

---
Tags: analysis
---


# Question
Title: Do any unique proof games feature an en-passant capture?
Most positions that could be reached, in a specified number of moves, after an *en passant* capture could be reached just as well without one, suggesting that such positions could not occur in unique proof games. It is, however, possible to have a pair of positions in which the unique shortest sequence of moves to get from one to the other would require an *en passant* capture. For example:

```
[Title "Goal: Black king on b6 and both pawns gone, in two moves"]
[FEN "8/1p/k/8/2P/8/8/5BK w - - 0 0"]

1. c5+ b5 2. cxb6+ Kxb6

```

There would be no way for White's pawn to disappear in only two moves without leaving a black pawn on the c file unless it was captured by Black's king at b6, and the only way for White's pawn to get there in two moves would be by first moving to c5 delivering check. Black's first move could not be b6, because that would leave Black in check from the bishop. If Black's first move didn't push the b pawn, however, it could not get captured on white's second move. Thus, the only possible first move for Black to reach the target position would be b5, followed by White playing cxb6, allowing Kxb6. Note that while Black would have legal first moves other than b6, none of them could yield the target position after only one additional move.

If one chooses a non-standard starting position, it's thus clearly possible for a unique sequence of moves to reach a specified other position to include an *en-passant* capture. Do any unique proof games that use the standard starting position have this interesting property?

# Answer
There are plenty! There are currently 158 currently in the Die Schwalbe Chess Problem Database.

For example, here is one with three consecutive en passants!

```
[Title "Thierry Le Gleuher, R028c Probleemblad 01/1999, 2. Preis ex aequo, Proof Game In 17.0 Moves"]
[FEN ""]

1. e4 d5 2. e5 Kd7 3. e6+ Kc6 4. exf7 e5 5. Ke2 Qf6 6. Kd3 Be7 7. f8=Q Be6 8. Qxb8 b5 9. Qxa8+ Kb6 10. Qe8 c5 11. Qg6 hxg6 12. Kc3 e4+ 13. d4 exd3+ 14. Kb3 d4+ 15. c4 dxc3+ 16. Ka3 c4+ 17. b4 cxb3#

```
> 10 votes

---
Tags: problems, retrograde-analysis, forced-move
---


# Question
Title: Point distribution of an "average" tournament
Maybe this is a bit too much towards math, but we have Noam :-)

If you view the final point standings of any tournament, you'll probably see many players with an average number of points, but few with a very high or low score. For Swiss this is almost by construction, but for a round robin (easier to analyze) it also resembles a Gaussian distribution.

My question is whether it is actually one, or something only similar, assuming some simplifications:

* n players play a round robin with n-1 rounds. n is assumed to be a very large number (ideally infinite).
* Each player is assumed to have equal strength.
* Thus the result of each game is (independently) 1, 1/2, 0 with probability p,1-2\*p,p with p in \[0,1/2\].

This should be homework for a statistics student...and I can immediately claim the mean of the score distribution is (n-1)/2 in any case.

# Answer
> 1 votes
It depends which quantities you are interested in; the whole distribution is a complex concept to describe.

Statistics that look at the score of a single player (mean, variance, etc.) are easy to compute, because they are the sum of independent game outcomes. It is essentially (up to rescaling) a multinomial distribution with k=3. So average scores, standard deviations, etc. are easy to compute. And the central limit theorem predicts that the limit for n to infinity is a Gaussian distribution with mean and variance that are easy to compute.

The trickier part is finding out quantities that involve the joint distribution of 2 or more player scores, since these scores are not independent: for instance, no two players can both score 0 in a round-robin tournament. So probabilities like "the probability that 5 different players score at least m points" are more complicated.

---
Tags: statistics, round-robin
---


# Question
Title: Why does stockfish make these strange recommendations?
The FEN is:

```
r2qk1r1/ppp2p1p/2n1bn1Q/4p1B1/8/2P4P/PP1NpKP1/R5NR b kq - 0 1

```

Clearly black is winning because the white bishop can be captured (with a discovery available if white recaptures). However, the stockfish eval seems strange - why would it suggest that playing an intermediate Rg6 is better? The continuation is Qh4 Rxg5 Qxg5 anyway, which is just a slower way to do the same thing. Wouldn't it be better to play the most direct move Rxg5?

Then I am also confused about the 3rd recommendation of e1=B+, why would it suggest to underpromote there?

# Answer
I think that in the case of the immediate ...Rxg5, Stockfish has seen one move deeper than in the version with ...Rg6 first. As a result the evaluation is slightly different - 0.1 less, in this case. So it ranks ...Rg6 first. It doesn't really matter either way, it's just an artifact of how engines work.

Same for ...e1=B+. It gets captured immediately, so it's effectively the same move as ...e1=Q+ that would also be captured immediately. Which one it happens to show is essentially random, it doesn't have a builtin preference for promoting to a queen in cases where it doesn't matter at all.
> 3 votes

# Answer
No particular reason. Note the scores, `-8.9` and `-8.8`, practically indistinguishable. Stockfish simply saw the same sequence of tactical response with and without the move `...Rg6`. The line `...Rg6` came first due to random fluctuation.
> 7 votes

---
Tags: stockfish, evaluation, pawn-promotion
---


title: Cheating Protocols

text:
# Question
Title: Cheating Protocols
Does FIDE (or any national federations) have any set protocols regarding detection of cheating? Or maybe a formal process for adjudicating suspicion? From what I can tell, the arbiter at St. Louis installed some screening and was in touch with Ken Regan, who has considerable experience in the field, but is that sort of thing standard? Because otherwise, I am seeing just a lot of opinion, i.e. GMs saying moves look "weird" and "not human" but such claims can be misleading and are hardly conclusive.

From what I can tell, screening measures on-site and detection re Regan's methods are hardly foolproof.

It seems like there should be a formal way to deal with suspicion that isn't "either have ironclad proof or shut up" but maybe I'm being naive?

# Answer
> 1 votes
The FIDE Handbook compiles all the FIDE regulations. There is a section about this topic: https://handbook.fide.com/chapter/AntiCheatingRegulations This looks like the same link that is in the comments... But, it is not!

However, the guideline in FIDE has been to allow the tournament director to use his/her good judgement. Not everything can be written.

Also, not all the tournaments are equal. There are tournaments with a big budget, and others with "zero" budget. If your budget is limited, it would be impossible to use some protocols.

In my perspective, without a clear evidence that a player is cheating, it is almost impossible that a tournament director changes a result.

---
Tags: rules, fide, cheating
---


# Question
Title: Comparative Advantage of Engine Improvements
I am implementing a chess engine in Python for the first time. Right now, my engine uses a standard alpha-beta search with fixed depth and a simple evaluation function that uses the weighted average of material for both sides. I have access to multiple cores, but I have not implemented any parallelization yet. I unfortunately have a limited time (just over a week) to make improvements before high stakes matches against a human and other engines. I've done a fair amount of research on engines, but I am not sure where to start in terms of making changes that actually improve the engine's strength. Which set of the following improvements might give me the best return on investment?

* Smarter move ordering for alpha-beta based on iterative deepening; *this is pretty much a given*
* Better evaluation function (piece-square table, time, other positional considerations)
* Naive parallelization (running minimax where each parallel search explore one path from the root at a time--this would not allow alpha-beta pruning)
* Search improvements (simple iterative deepening/aspiration windows, killer moves)
* Different search algorithm (PVS, MTD, Lazy SMP, YBW)
* Managing time and determining search depth dynamically (the game will be a blitz game)
* Transposition table
* Using opening books
* Porting the python code to c++
* Something else!

# Answer
> 3 votes
Caveat: my experience with minimax engines involves coding a Connect Four engine over a few years, and working a bit with Stockfish (partly as a user, partly with the code). I haven't actually coded a chess engine by myself. That said, I'd recommend the following (not in any particular order, though some features enable others):

* As Kevin said, C++ should give you a big speedup.
* A transposition table seems like one of the easiest things to do on your list, and it should give you a good speedup.
* Managing time definitely seems good, especially if it will be a blitz game.
* For determining the search depth, I'd recommend iterative deepening search. This will help you with a few things:
    + Dynamic time/search depth management (after each iterative deepening step, you can just check if a certain time has been exceeded; if so, stop searching and make a move).
    + Move ordering. The data you get from a depth n search can then inform your engine on which moves to consider first in the depth n+1 search. For this, the transposition table would be helpful and needed. For the info you store in the TT for each node, you could also store (in addition to the evaluation) which moves the engine currently thinks are best, in order. This can be used and updated by future nodes at higher iterative deepening stages.

# Answer
> 2 votes
If your code is doing the bulk of its work in python, you can probably get a 5x or 10x speedup by porting to C++.

---
Tags: engines, programming
---


# Question
Title: Chess middle game puzzle online for free
Recently, I was looking for a website where I can find only middle game puzzles. I found the website, I had solved most of the puzzles in less than a minute (If I get enough time, I can solve any puzzles between 0-1700 (If I rush little bit I make mistakes even in 700, for that reason I am gonna call myself not-speedy-player)). Anyway, I was thinking of improving "my thinking knowledge", by doing chess puzzles as I did for tactics. When I play a game in online, I feel like, my opponent is playing too fast, so I have to unless I will lose on time. That's why I am planning to play middle game puzzles. And when I read Silman's book, sometimes I feel like I am at 1800+ rated player (There's also another reason, I can beat upto 2000 rating bot in chess.com average time). But, I am too lazy to memorize more than 8 moves (using Board also works, but I read it at night in dark room).

**Is there a website where I can freely play middle game puzzles?** There's currently two sites I know, lichess and chess.com. I already have 2000 ratings in puzzle in an account in chess.com but the fact is I can't afford membership. There's also a reason why I can't play puzzles in lichess. Default puzzles rating is too low and I can solve them but I get tired after getting around 100 ratings and lose 200 ratings. And I don't get that much of time to solve tactics. But I will be happy if I can do 5-10 puzzles in a day. FYI, I had found a website around 5-6 months ago where I could choose options for different type (openings, middle-game, endgame). I was bad at tactics that's why I stopped solving problem there. And after reinstallation of my OS I lost that history. That's why I am sure that there's an website on middle-game puzzle (the website's design was poorly developed so it's not SEO. I can't find by quick internet search)

# Answer
> 3 votes
Lichess is completely free and offers middlegame puzzles: https://lichess.org/training/middlegame .

# Answer
> 2 votes
The site you used was most likely Chesstempo, one of the greatest sites for training. It's even one of the most innovative (see endgame puzzles or technology similar to chessables Move-Trainer), despite its design, which looks like it was from 15 years ago... You get unlimited free chess tactics, but only 2 free endgame puzzles in a day.

---
Tags: strategy, puzzles, middlegame, websites
---


# Question
Title: Why does Stockfish evaluates the trade of a B vs N that bad, while the trade has the King in the open and doubles pawns?
In this position (White to play)

<sub>(Picture credits to the chess compass extension that analyzes a chess.com game after it ended)</sub>

The current Stockfish evaluation (before White plays) is ~0.0.

But SF would give a -0.8 (+0.8 for Black) if Bg5 takes Nf6 (playing around with SF, the rating goes from -0.9 \[picture\] to a max at -0.3). Next, SF recommends to take the B, gxf6.

Why would that be?

* Is it because a B is usually worth more than a N?
* or in this particular position B had better opportunities rather than take the N?

# Answer
You seem to have made some random repetition moves Ra1-Re1 and Ra8-Rb8 before this position, so that Ra1 would be a draw as indicated by your graphic. This makes no sense otherwise, because Ra1 hangs the knight on e2. If not for the previous moves that lead to threefold repetition, the real evaluation of this position is that **black is much better** (more than -1 advantage, possibly winning) even though **Bxf6 is the best move**.

Why is Bxf6 the best move? This is an endgame (or late middlegame), and Bxf6 doubles blacks pawns and isolates the h pawn, both of which can become weaknesses for you to attack. Possibly even more important than this is that the black knight has prospects to jump to e4 or d5 and wreak havoc on white's position, while the white bishop is awkwardly placed blocked by white's own pawn on f4. Thus, this is a trade of a bad bishop for a good knight which is a good idea for white.

Nevertheless, white is still worse because black has the bishop pair and more space on the queenside. White's pieces are placed somewhat awkwardly, especially the b3 knight which is trapped by black's pawns and unable to advance forward. The knight on e2 blocks white's control of the e file, but cannot easily be moved without hanging the f4 pawn. The piece coordination is nonexistent in white's camp, but perfectly harmonious for black.
> 2 votes

---
Tags: analysis, stockfish, trading, king-safety
---


# Question
Title: Why do all e4-c5 variations only have a single name (Sicilian Defence)?
I was wondering why e4-e5 openings have different names depending on the next move, but Sicilian Defence continuations are all just variations of the Sicilian Defence. Is that because they are frequently transposed into one another, or is there another reason?

For me personally they do differ a lot. The Accelerated Dragon variation and the Najdorf have different piece coordination and have a lot of theory for a simple "variation."

# Answer
Back in the day where most openings got their names, 1...e5 was much more popular than the Sicilian, so it made sense to distinguish between the King's Gambit, the Italian and so on as those were the openings everyone was playing.

The Sicilian however, was much more obscure until the 20th century, so people felt no need to be more specific about it.

It's a bit similar to the distribution of ECO codes, where openings that were popular at the time they were established get a wider range of entries.
> 15 votes

# Answer
Your premise is wrong, in my opinion.

1.e4 e5 *does* have its own name that the rest are variations of -- it's the Open Game (although most people just refer to it as "1...e5", but that's still refering to the opening as a whole). And lines within the Sicilian do have their own names, you mention the Najdorf and the Accelerated Dragon, comparable to say the Ruy Lopez and the Italian.

So I don't see a real difference.
> 7 votes

---
Tags: opening, sicilian-defense, terminology
---


title: Shocking queen sacrifices?

text:
# Question
Title: Shocking queen sacrifices?
I am a chess beginner and I find queen sacrifices are the most shocking moves I have ever seen.

Please, can you provide me with some shocking examples of queen sacrifices. It need not be a big list, a handful would work just fine.

# Answer
My favourite is this one, it has a nice anecdote attached to it, too. *Supposedly*, in the situation shown on the board, due to his overwhelming advantage, the white player has kindly asked his rival on which square he would like to receive the checkmate. The black player responded:

> g1 (as this he thought least likely within the foreseeable future)

```
[White "Edward Lasker"]
[Black "George Alan Thomas"]
[FEN "rn3rk1/pbppq1pp/1p2pb2/4N2Q/3PN3/3B4/PPP2PPP/R3K2R w KQ - 0 1"]

1. Qxh7+ Kxh7 2. Nxf6++ Kh6 3. Neg4+ Kg5 4. h4+ Kf4 5. g3+ Kf3 6. Be2+ Kg2 7. Rh2+ Kg1 8. Kd2# {Some sources say 8. 0-0-0#} 1-0

```

Another shocking queen sacrifice comes from this game, which is by some called the most beautiful in the history of chess. The result of the sacrifice is an instant resignation.

```
[Event "18th DSB Kongress"]
[Site "Breslau GER"]
[Date "1912.07.20"]
[EventDate "1912.07.15"]
[Round "6"]
[Result "0-1"]
[White "Stefan Levitsky"]
[Black "Frank James Marshall"]
[fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1.d4 e6 2.e4 d5 3.Nc3 c5 4.Nf3 Nc6 5.exd5 exd5 6.Be2 Nf6 7.O-O Be7 8.Bg5 O-O 9.dxc5 Be6 10.Nd4 Bxc5 11.Nxe6 fxe6 12.Bg4 Qd6 13.Bh3 Rae8 14.Qd2 Bb4 15.Bxf6 Rxf6 16.Rad1 Qc5 17.Qe2 Bxc3 18.bxc3 Qxc3 19.Rxd5 Nd4 20.Qh5 Ref8 21.Re5 Rh6 22.Qg5 Rxh3 23.Rc5 Qg3 0-1

```

Fischer's "Game of Century" - played by him when he was only 13 years old!

```
[Event "Third Rosenwald Trophy"]
[Site "New York, NY USA"]
[Date "1956.10.17"]
[EventDate "1956.10.07"]
[Round "8"]
[Result "0-1"]
[White "Donald Byrne"]
[Black "Robert James Fischer"]
[fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1. Nf3 Nf6 2. c4 g6 3. Nc3 Bg7 4. d4 O-O 5. Bf4 d5 6. Qb3 dxc4 7. Qxc4 c6 8. e4 Nbd7 9. Rd1 Nb6 10. Qc5 Bg4 11. Bg5 Na4 12. Qa3 Nxc3 13. bxc3 Nxe4 14. Bxe7 Qb6 15. Bc4 Nxc3 16. Bc5 Rfe8+ 17. Kf1 Be6 18. Bxb6 Bxc4+ 19. Kg1 Ne2+ 20. Kf1 Nxd4+ 21. Kg1 Ne2+ 22. Kf1 Nc3+ 23. Kg1 axb6 24. Qb4 Ra4 25. Qxb6 Nxd1 26. h3 Rxa2 27. Kh2 Nxf2 28. Re1 Rxe1 29. Qd8+ Bf8 30. Nxe1 Bd5 31. Nf3 Ne4 32. Qb8 b5 33. h4 h5 34. Ne5 Kg7 35. Kg1 Bc5+ 36. Kf1 Ng3+ 37. Ke1 Bb4+ 38. Kd1 Bb3+ 39. Kc1 Ne2+ 40. Kb1 Nc3+ 41. Kc1 Rc2# 0-1

```

The "Swindle of the Century" game. Perhaps not very spectacular, but how shocking it must have been to the black player!

```
[Result "1/2-1/2"]
[White "Larry Melvyn Evans"]
[Black "Samuel Reshevsky"]
[fen "2Q5/5Rpk/8/1p2p1qp/1P2Pn2/4rPPP/7K/8 w - - 0 1"]

1. h4 Re2+ 2. Kh1 Qxg3 3. Qg8+ Kxg8 4. Rxg7+ 1/2-1/2

```

The "Immortal Draw" game:

```
[Event "Vienna"]
[Site "Vienna"]
[Result "1/2-1/2"]
[White "Carl Hamppe"]
[Black "Philipp Meitner"]
[fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1. e4 e5 2. Nc3 Bc5 3. Na4 Bxf2+ 4. Kxf2 Qh4+ 5. Ke3 Qf4+ 6. Kd3 d5 7. Kc3 Qxe4 8. Kb3 Na6 9. a3 Qxa4+ 10. Kxa4 Nc5+ 11. Kb4 a5+ 12. Kxc5 Ne7 13. Bb5+ Kd8 14. Bc6 b6+ 15. Kb5 Nxc6 16. Kxc6 Bb7+ 17. Kb5 Ba6+ 18. Kc6 Bb7+ 1/2-1/2

```

You can find many more in these game collections:
> 14 votes

# Answer
Here one of the craziest queen sacrifices that I have ever seen:

```
[Event "Hoogovens"]
[Site "Wijk aan Zee NED"]
[Date "1996.01.16"]
[EventDate "1996.01.13"]
[Round "3"]
[Result "1-0"]
[White "Vassily Ivanchuk"]
[Black "Alexey Shirov"]
[ECO "D44"]
[WhiteElo "?"]
[BlackElo "?"]
[PlyCount "69"]
[fen ""]
[Startply "41"]

1.d4 d5 2.c4 c6 3.Nc3 Nf6 4.Nf3 e6 5.Bg5 dxc4 6.e4 b5 7.e5 h6
8.Bh4 g5 9.Nxg5 hxg5 10.Bxg5 Nbd7 11.exf6 Bb7 12.g3 c5 13.d5
Qb6 14.Bg2 O-O-O 15.O-O b4 16.Na4 Qb5 17.a3 exd5 18.axb4 cxb4
19.Be3 Nc5 20.Qg4+ Rd7 21.Qg7 Bxg7 22.fxg7 Rg8 23.Nxc5 d4
24.Bxb7+ Rxb7 25.Nxb7 Qb6 26.Bxd4 Qxd4 27.Rfd1 Qxb2 28.Nd6+
Kb8 29.Rdb1 Qxg7 30.Rxb4+ Kc7 31.Ra6 Rb8 32.Rxa7+ Kxd6 33.Rxb8
Qg4 34.Rd8+ Kc6 35.Ra1 1-0

```
> 5 votes

# Answer
Nakamura in 2007: Michal Krasenkow vs Hikaru Nakamura

```
[Event "Casino de Barcelona"]
[Site "Barcelona ESP"]
[Date "2007.10.19"]
[EventDate "2007.10.18"]
[Round "2"]
[Result "0-1"]
[White "Michal Krasenkow"]
[Black "Hikaru Nakamura"]
[ECO "A14"]
[WhiteElo "2668"]
[BlackElo "2648"]
[PlyCount "56"]
[fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1. Nf3 Nf6 2. c4 e6 3. g3 d5 4. Bg2 Be7 5. O-O O-O 6. b3 a5
7. Nc3 c6 8. d4 Nbd7 9. Qc2 b6 10. e4 Ba6 11. Nd2 c5 12. exd5
cxd4 13. Nb5 exd5 14. Nxd4 Rc8 15. Re1 b5 16. Bb2 Re8 17. Qd1
bxc4 18. bxc4 Qb6 19. Rb1 dxc4 20. Nc6 Rxc6 21. Bxf6 Qxf2+
22. Kxf2 Bc5+ 23. Kf3 Rxf6+ 24. Kg4 Ne5+ 25. Kg5 Rg6+ 26. Kh5
f6 27. Rxe5 Rxe5+ 28. Kh4 Bc8 0-1

```
> 5 votes

# Answer
There are so many games to choose from! The following queen sacrifice was quite shocking, at least the opponent didn't anticipate it.

```
[FEN ""]
[Event "Zurich Candidates"]
[Date "1953.09.23"]
[Round "14"]
[Result "0-1"]
[White "Yuri Averbakh"]
[Black "Alexander Kotov"]
[StartPly "59"]

1.d4 Nf6 2.c4 d6 3.Nf3 Nbd7 4.Nc3 e5 5.e4 Be7 6.Be2 O-O 7.O-O
c6 8.Qc2 Re8 9.Rd1 Bf8 10.Rb1 a5 11.d5 Nc5 12.Be3 Qc7 13.h3
Bd7 14.Rbc1 g6 15.Nd2 Rab8 16.Nb3 Nxb3 17.Qxb3 c5 18.Kh2 Kh8
19.Qc2 Ng8 20.Bg4 Nh6 21.Bxd7 Qxd7 22.Qd2 Ng8 23.g4 f5 24.f3
Be7 25.Rg1 Rf8 26.Rcf1 Rf7 27.gxf5 gxf5 28.Rg2 f4 29.Bf2 Rf6
30.Ne2 Qxh3+ 31.Kxh3 Rh6+ 32.Kg4 Nf6+ 33.Kf5 Nd7 34.Rg5 Rf8+
35.Kg4 Nf6+ 36.Kf5 Ng8+ 37.Kg4 Nf6+ 38.Kf5 Nxd5+ 39.Kg4 Nf6+
40.Kf5 Ng8+ 41.Kg4 Bxg5 42.Kxg5 Rf7 43.Bh4 Rg6+ 44.Kh5 Rfg7
45.Bg5 Rxg5+ 46.Kh4 Nf6 47.Ng3 Rxg3 48.Qxd6 R3g6 49.Qb8+ Rg8
0-1

```
> 3 votes

# Answer
The earliest sound positional sacrifice of the queen is:

```
[fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1.d4 d6 2.e4 Nc6 3.Nf3 Bg4 4.d5 Ne5? 5.Nxe5! Bxd1 6.Bb5+ c6 7.dxc6 Qa5+ 8. Nc3 O-O-O 9. Nc4 Qb4 10.a3 Qc5 11.Be3 Qh5 12.Rxd1

```

This leads to a position where white has two pieces, a pawn and fantastic positional compensation for the queen.
> 3 votes

# Answer
The 'immortal game' has a queen sacrifice, followed by two rook sacrifices. White went on to win, mating with two knights, a bishop and a pawn.
> 2 votes

# Answer
Lilienthal-Capablanca 1935: See http://www.chessgames.com/perl/chessgame?gid=1090860.

Lilienthal said in an interview in New In Chess that Bobby Fischer introduced himself to him with "e takes f6".
> 2 votes

# Answer
Kramnik v. Kasparov in Munich, 1994. Kasparov sacrificed his queen on move 12!

```
[Event "Munich (Germany)"]
[Site "http://lichess.org/ZmQyTtlz"]
[Date "1994"]
[White "Vladimir Kramnik"]
[Black "Garry Kasparov"]
[Result "0-1"]
[PlyCount "78"]
[ECO "E92"]
[Opening "King's Indian Defense: Petrosian Variation, Stein Defense"]
[Termination "Normal"]
[fen "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"]

1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 O-O 6. Be2 e5 7. d5 a5
8. Bg5 h6 9. Bh4 Na6 10. O-O Bd7 11. Nd2 Nc5 12. b3 Nfxe4
13. Bxd8 Nxc3 14. Qe1 Rfxd8 15. Rc1 Nxa2 16. Ra1 Nb4 17. Bd1 e4
18. Rb1 Re8 19. Qe3 f5 20. h4 Rf8 21. g3 Rae8 22. Kg2 Nbd3
23. Rg1 f4 24. gxf4 Rxf4 25. h5 g5 26. Rf1 Rh4 27. Rh1 Rf4
28. Rf1 Ref8 29. f3 Rh4 30. fxe4 Nf4+ 31. Kg1 Ncd3 32. e5 Nxe5
33. Rc1 Rh3 34. Nf3 g4 35. Nxe5 Rxe3 36. Nxd7 Nh3+ 37. Kg2 Rxf1
38. Kxf1 g3 39. Kg2 Nf4+ 0-1

```
> 2 votes

# Answer
This is the most shocking queen sacrifice I've seen. I saw it live and struggled to believe it.

```
[Title "Jonah Willow vs Neil Berry 4th EJCOA IM 2022"]
[fen ""]
[Startply "19"]

1. Nc3 Nf6 2. e4 e5 3. Nf3 Nc6 4. Bb5 Nd4 5. Ba4 c6 6. Nxe5 d6 7. Nf3 Bg4 8. d3 Bh5 9. Rg1 b5 10. Nxd4 Bxd1 11. Nxc6 Qc8 12. Bxb5 Nd7 13. Kxd1 Qb7 14. Be3 Be7 15. e5 a6 16. Ba4 Bd8 17. Ne4 O-O 18. Nxd6 Qxb2 19. Bd4 Qa3 20. Bb3 Nxe5 21. Bxe5 Qc5 22. Ba4 Qxf2 23. Bd4 Qf4 24. Ne4 f5 25. Nd2 Bf6 26. Nf3 Bxd4 27. Ncxd4 Qd6 28. Re1 Kh8 29. Rb1 Rab8 30. Rxb8 Rxb8 31. Bb3 g6 32. Re6 Qf4 33. g3 Qg4 34. Kd2 Rd8 35. Kc3 Rc8+ 36. Bc4 Qh3 37. Re7 Qh5 38. Ne5 Rb8 39. Ndf3 f4 40. g4 1-0

```
> 2 votes

# Answer
I post this answer in case the OP or anyone else is here for information to help their own play. Either to learn how they might offer their queen to try to trap their opponent, or how taking their opponent's queen might turn out to fall into their opponent's trap. One such trap is Légall's mate. Positions amenable to setting this trap can be reached in a number of ways. Here's one example, where Black plays the Petrov, sacs their queen and traps White:

```
[Title "Black traps White in the Petrov"]
[FEN ""]

1. e4 e5 2. Nf3 Nf6 3. Nxe5 Nc6?! {The Stafford Gambit. d6 is best.} 4. Nxc6 dxc6 5. d3 Bc5 6. Bg5? {h3/f3/Qf3 are best} Nxe4! 7. Bxd8? Bxf2+ 8. Ke2 Bg4#

```
> 1 votes

---
Tags: tactics, sacrifice, queens, queen-sacrifice
---


# Question
Title: Position where neither player can force an *exact* outcome
There are three possible outcomes of a game of chess: white wins, black wins, or the players draw.

Typically, we consider a win better than a draw, so when we say "white can force a draw" from a given position, usually we mean "white can force a draw *or better* (a win)". For the purposes of this question, consider the three possible results of a game as entirely separate possibilities. For example, in this question, a position is given where

* white cannot force a win nor a draw (remember, *exactly* a draw),
* black cannot force a win, nor a draw, nor a loss, but
* white can force a loss.

(This is interesting because "neither player can force a win nor \[exactly\] a draw".) Is something more extreme possible? Is there a position where

* white cannot force a win, nor a draw, nor a loss, and
* black cannot force a win, nor a draw, nor a loss?

For example, this would mean that if white attempts to force a white loss, then they cannot because black can force that either white wins or the players draw (but without actually being able to choose which).

# Answer
Such a position must be a draw with best play. Here's one where either player can make a winning threat that can only be parried by giving checkmate:

```
[Title "Neither player can force an exact outcome"]
[FEN "2n4k/2P3pP/6P1/8/8/6p1/2p3Pp/2N4K w - - 0 0"]

1. Nd3 Nd6 2. Ne5?!?

```

Best play is for White and Black to keep moving their Knights back to c1 and c8 respectively. But either player can prevent a drawn outcome by threatening mate in at most two moves with Ne5 or ...Ne4, forcing the opponent to either mate in 1 (by promoting to Q or R) or get mated.
> 11 votes

# Answer
> Is there a position where white cannot force a win, nor a draw, nor a loss, and black cannot force a win, nor a draw, nor a loss?

Of course there is. It's a position we are all very familiar with. Here it is:

```
[fen ""]

```
> 2 votes

---
Tags: problems
---


# Question
Title: What explains self destructive behaviour?
I was recently playing chess and lost a few games back to back. I don't know why but I played several games after that and lost all of them deliberately. Making it extremely easy for the opponent to defeat me. (eg: handing over all my pieces to be killed). I lost 100 Elo rating points which I had worked hard to attain. Has anybody else been in this mental zone where you just go into ultimate self destructive mode? or have you come across a player like that?

# Answer
People do this all the time when they are frustrated, not just in chess. The term is called tilting. I've fallen victim to this state many times. https://en.wikipedia.org/wiki/Tilt\_(poker)

A notable example of a top player tilting is Duda in his match against Nakamura in the recent Chess.com Global Championship Finals, where Nakamura was leading 3-0 in their 4 game match, and Duda began the final game with 1.e3? and 2. Ke2?!

Nakamura went on to win their match that day 4-0.
> 3 votes

# Answer
It would be a wonder if not (therefore I suggest to rephrase your question a bit, forist surely will make helpful suggestions how).

I myself most definitely am an example, for fuzzy values of "deliberately". It just happened in this years German seniors championship. I come into the venue in the 6th round, and the arbiter tells me that the opponent forfeited due to sickness.§ This put me into a mental state of "Even if I should win this tournament, I don't deserve it, and Karma will be evened by WW3 starting. Or suchlike. Has happened before." Consequently, I played much worse for the rest of the tournament and literally got my posterior handed to me the last round.

§Which is always a danger in a senior tournament with Swiss and overnight pairings. Happened again in the Hamburg ch, but there I was the high favorite anyway, thus didn't fell into this trap and won big time. (And yet, WWIII still hasn't started.)
> 1 votes

---
Tags: psychology
---


# Question
Title: Comments and advice on a game that I played against 1.h4
I was playing a game with the Black pieces the other day against 1. h4. The reason why I wanna discuss this game with you is that during the game I always felt that my position is not stable, and at some point I was up by a pawn, but white had a lot of files to attack me and I needed to defend and it was uncomfortable. The engine gives an evaluation of -2.7 at the end but to me it was so unclear. I would really appreciate your feedback about the game in general in order for me to understand the position better so that next time I can evaluate the position better during the game and not be worried that I might be worse (although the engine says that I'm much better by -2.7). Moreover, I read somewhere that if your opponent plays 1.h4, then it's good to respond with 1...d5 opening the light-square bishop, and if your opponent plays 1.a4, then it's good to respond with 1...e5 opening the dark-square bishop. What do you think about this general tip? Also when your opponent plays 2. h5, do you prefer to play 2...h6, or do you continue occupying the center and fast development?

```
[FEN ""]
 1. h4 d5 2. h5 h6 3. Nf3 c5 4. d3 Nf6 5. Nbd2 Nc6 6. e4 Bg4 7. Be2 e6 8. Nh2 Bxe2 9. Qxe2
 Bd6 10. Nhf3 Be7 11. e5 Nd7 12. Nf1 O-O 13. g4 Qa5+ 14. Bd2 Qc7 15. O-O-O Ndxe5 16. Nxe5
 Qxe5 17. Qxe5 Nxe5 18. Nh2 Nc6 19. f4 e5 20. fxe5 Nxe5 21. Rde1 Bd6 22. Reg1 Rae8 23. g5
 hxg5 24. Rxg5

```

# Answer
When playing through this game, at no time did I think that Black was losing.

I don't like 2...h6 myself. What are you doing? Preventing 3.h6? Why would you want to prevent that?

The other move I don't like is 12...O-O. The center is closed and it doesn't seem like your king is particularly unsafe in the middle or queenside. Your opponent has already spent two moves advancing the h-pawn; it's rather obvious that if you castle over there, they're going to play O-O-O and advance the g-pawn. Your h6 pawn makes a nice target. And it seems like it's difficult for your knights to get over to defend right away because of the e5 pawn. I wouldn't say it's a *bad* move, but it's very foreseeable that it would lead to you being on the defensive.
> 10 votes

# Answer
Just answering the comment from D M's answer.

1. Following general principles, control the center. e5 and d5 are both good moves. In response to h6, you could capture and make white waste time trying to regain the material, or just play g6 and show that it's more of a weakness than a strength.
2. I would play Bg4 with the intent of capturing on h5. There's also nothing wrong with e5 and a plan similar to any KID.
3. On move 10, Be7 is correct due to the fork threat. The queen is good on c7 and b6. You can castle on either side safely, but white has to tend to their h5 weakness, so queenside is better for both. The space gained by c5 actually protects your king well.
> 4 votes

# Answer
When I saw the position, my first impression was, g pawn is so sad cause if opponent double his rook on g file, it will be harder to safe it. So I immediately thought I have save it.

h file is also open from black's view but not in the chess board. Your king is safe on h and g file.

I am going to show two move I immediately thought of, 24..... f6 and 24.... Kh7.

Let's start with a variation for the second move.

24.... Kh7 25. h6 Hoping for gxh6 that way g and h file will be open from white's perspective. (more info will be added at last). But g6 saves the game and you got your advantage g pawn "well" protected and h file is also protected by opponents pawn if it was open, you will be trouble. Stockfish doesn't like the 24.... Kh7 also doesn't hate it. So it's playable.

Why does Stockfish loves f6 instead of Kh7?

It's simple. When you play f6, there will be tempo on opponents rook so you get "an extra move" and also opens up the possibility to save g pawn by Rf7 and Re7. If there was instantly an attack on the g pawn then I will consider going with Rf7 cause it tells bishop to go to f8 to save g pawn and Rook is superior so it will do it's job. Whereas Re7 will block the diagonal of the bishop.

So just think that, you gotta play a move which will tell another piece what to do. That's the simple strategic plan. Also it is said that you don't have calculate 20 lines. **Make short plan, cause in middle you don't know what your opponent is gonna do** unless your opponent is Stockfish.

If I were said to play the position, I will consider playing both of the moves I mentioned above, also everytime I will look for better ones if there is. Where Stockfish will play f6 forever.

Let's go to :

# Why are you safe in the position?

You castled kingside, so the safest file for your king is h and g. You are safe unless the files are from white's perspective.

##### What do I mean by open file from white's perspective?

Take your position as example. g file is open from white's perspective cause there's no white's pawn to stop white's attack. Whereas if white had doubled his rook on h file then it would be useless cause there's no attack white got no way to open up the h file unless you are willing to do so. So white will try to take full control of the g file cause there's "no way black can stop the attack" unless you are wise enough.

---

As I said earlier, you gotta use superior piece for attacking and minor piece for defending (if necessary) so use your bishop for defending g pawn and use rook to attack.

Let's look at Stockfish's move for the position you gave.

24... f4 (talked about it). 24 .... Kh7 (also talked about it) (it's recommended by Stockfish as 3rd move at 20th depth).

24... Re7 followed by f6 if white doubles rook on g file, I don't know why stockfish loves it more than Kh7. cause it takes diagonal of the dark squared bishop.

24... Re6 at first sight I thought it's shitty moves cause it gives away the g pawn. Let's look at the variation 25. Rg1 Kh8. 26. Rxg7 Ng6! (great move giving away the knight and taking a rook). Let's look at another variation: 25. Rg1 g6 26. hxg6 fxg6. I don't like the variation cause all kingside files are open. But Stockfish likes it cause there's no threat g pawn is well protected by the rook and knight. King is also coming to protect. But as a human I may make mistake later in the game for that reason, I don't like it. Also, first variation tricks the opponent.

When you play a game, ask yourself, the files are open but is there attack? Can he attack? If so, can I defend? If there's a way to defend, you are safe. If there's no attack, start your attack so opponent can't start his. He will spend rest of the game defending. **But don't overrush.**

General Philosophy behind h4 and a4 :

If someone starts with h4 it means, he is likely start his attack on the kingside. and for a4 queenside attack. You don't have to worry about it in the beginning. But in middle-game. In some particular positions instead of castling I will put my king on the f7 and pawn on f6 and e6 if possible. In response to a4 and h4, you can play d4 and e4 whatever you are more familiar with. But b4 has theory. You can learn b4's theory if you like to surprise people. If you like to counterattack then start your attack queenside after developing all your pieces including queen but not rook. If you had put Qc7 then you could confuse your opponent by which way you will castle so his attack might become useless as kingside is already weak for white. You could bring your pieces there faster and start attack there if he had castled kingside and if he castled queenside your pawns will say "Hi" to the opponent's king.

Let your pieces speak for themselves.
> 2 votes

---
Tags: analysis, strategy
---


title: Definition of opposition

text:
# Question
Title: Definition of opposition
This just came up in my youth chess training.

A very general definition of "having the opposition", including even rare cases, is

* A: All corners of the (axis-parallel) rectangle spanned by the two kings have the same color, the opponent has the move.

A more "operational" description of "having the opposition" is

* B: Regardless how the opponent king walks out of opposition, you can walk in again.

Prove A=\>B. (Danger, the board has edges, so you have to include in your proof that the mobility of your king may be limited!)

EDIT: Of course, see comment below, it is assumed that the board is empty except the two kings. Otherwise "opposition" might be meaningless due to inaccessibility of squares to the kings, and the more general theory of "corresponding squares" sets in.

# Answer
Although not a mathematician, my answer is the following. Consider the chessboard as having Cartesian coordinates, such as columns 0 to 7 and rows 0 to 7. Similar reasoning applies if 1 to 8 is chosen. The position of a king can be represented by a two item tuple, column first then row. Kings on opposite ends of a long diagonal would be W(0,0) and B(7,7) . In the above formulation the kings will be in opposition if the differences between their corresponding tuple items are both even. Consider zero as even and both differences being zero is prohibited as they cannot occupy the same square. This meets the definition A in the query. For example with W(0,0) & B(2,4) and it's Black's move, White ( side not to move ) has the opposition. If the Black king moves he must change either item by one or both. White simple changes the corresponding item ( coordinate ) or both. If the White king is in a corner he can still change each coordinate, or both, by one. This satisfies B in the query. The other king can always walk back into opposition.
> 2 votes

# Answer
Two kings are in **direct opposition** if they're on the same row or column separated by just one square. Two kings are in **diagonal opposition** if they're facing each other diagonally with one square in between. In both cases the player not having the turn has the opposition.

**Indirect opposition** is harder to define because different people will mean different things depending on context. The most practical definition is probably "a player has the indirect opposition if he can force his opponent to concede the opposition.

As you say in the question, the rectangle rule can give us a hint but squares defended by pawns can make a player lose this type of opposition.
> 1 votes

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Tags: mathematics, opposition
---


# Question
Title: How does White “waste” a tempo in the Botvinnik-Carls defence in the Caro-Kann?
In this Hanging Pawns video, Mr. Tomic around 1:40, makes a statement, “White actually wasted three tempi to play e4, d4 and e5 so this takes away a tempo for White in exchange for a sacrificed pawn…” I don’t understand. Why are the tempi wasted? Like, White has good control over d6 and more space even though the centre is damaged. In general, I had thought that a series of moves like Bf5 and then Bc8 was what losing a tempo meant. Can someone help me here?

# Answer
> Why are the tempi wasted?

They were not strictly speaking wasted, they were spent and when White played dc they were exchanged. It is tempting to suggest that Tomic's mother tongue is not English and that he misspoke. However I think he is making a subtle point.

White has spent 3 tempi (e4, d4, e5) on building an impressive center. When Black plays c5 White has a choice. Play something like c3 and preserve the center or take the free pawn when the previously impressive center crumbles away to almost nothing.

This is the sense in which Tomic is saying the moves were "wasted". The impressive center those moves built has gone. However in return White has an extra pawn. They weren't so much wasted as the strong center was exchanged for an extra pawn.
> 5 votes

# Answer
Normally we say a player is losing a tempo in the opening when he's doing a move doesn't help development. Most players wouldn't call those moves "wasted" tempi, since they do indeed help with development. They're not development moves themselves so that's probably where the author is coming from, but they open up options for the bishops.

The only move which could perhaps be considered a wasted tempo is e5, but it still helps White get more space. Note that Black's moves weren't developping moves either

Anyway I wouldn't overthink it too much. How the position was reached or what the current "tempo count" doesn't really matter (specially with this kind of locked central structure). We should focus instead on the resulting position and the plans available for each side. The effectiveness of those plans and the actions the opponent can take against them is what will determine the evaluation of the position.
> 2 votes

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Tags: caro-kann, tempo
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# Question
Title: Does having played the actual game make it easier to spot a tactic?
So, I looked at a tactic quiz for my kiddies. I needed whopping five seconds to see that a fork (yes, that was given too!) could be applied on a square that wasn't really protected due to a pin. (I'm a big pin-overlooker, shame on me.)

Now, assume I had actually played that game. This pin surely was existent through numerous moves before, and probably at least one calculation had involved it, so I guess I had seen the move in a fraction of a second.

Thus: I assume that having actually played the game will make finding tactics easier due to "priming". This might be tested by splitting into two groups, one just gets the position, one shall replay the game move for move and "look for tactics". (Details of the methodics must be worked on still.)

**In seeking a factual, cited, non-opinion-based answer: Has anyone already tried that? (If yes: Is my offhand theory correct?)**

(I expect an even larger priming effect on finding good strategic moves.)

# Answer
It depends.

Sometimes you set up tactics during games (Example: Pinning a pawn to threaten a piece, which is now undefended due to the pin), and this of course makes it really easy to spot tactics when your opponent overlooks them.

However, sometimes during games, you are maybe focused on one part of the board and not paying that much attention to the other. This can cause you to overlook tactics on the opposite side. As an onlooker, you will scan the entire board, which makes you more likely to spot the tactic.
> 5 votes

# Answer
I'm a very, very, very amateur player, so advice others have given is probably better for you, but if it's got a list of the moves in the game to get to that point, I think I'd actually place the pieces on the board, and make the moves, to see how things develop to get to that point, and analyze it from both sides.
> 2 votes

# Answer
* Our brain mostly works on habits everyday whether one is aware of it or not. So one can be good at an activity based on how many repetitions/ frequency he has performed that apart from one's own intelligence.
* By playing many games it is much easier for the brain to sort the previous pattern from memory and tell you the best move in the position. This can be easily verified by the online game vs offline game. If you have played thousands of chess games online and solved many puzzle rushs and then you play a offline game for the first time, then you won't be finding the best move or forks immediately because those visuals are new to the brain although not the game itself. That is why players are prepared for both the offline and online games depending on what platform they are playing.
* It depends on other factors such as mood, environmental factors which in turn can affect one's game.
> 1 votes

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Tags: tactics, psychology
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# Question
Title: Adding "summary" comments to an analysis
When I analyze my chess games for studying, I like to write a high level summary or action items.

For example, a summary of a game might include some positive feedback for myself, as well as constructive action items:

> 1. Good job managing my time. I stayed ahead on the clock the whole game.
> 2. I need to review how to punish ...Nc6.
> 3. I could have mated in fewer moves. Review King/Rook mating pattern again.

These are distinct from per-move analysis comments, because they apply to the entire game.

Is there a standard practice for storing this type of information? It would be great if I could store it in a PGN so that I have all my analysis and game data in one file, but I haven't seen something like this described in any of the PGN specifications.

# Answer
> 3 votes
You can put comments, contained within {}, almost anywhere in your pgn file. The obvious place to put summary comments is in between the header information, e.g. {White "name"\], \[Black "another name"\], and the first move.

# Answer
> 3 votes
There is nothing like that for PGN. You can, thus, do almost what you like, and what your particular PGN software allows you to do.

You should be aware that comments are poorly defined by the PGN standard, especially in context where exchange of PGN files are concerned. One point is that long comments inside the movetext area must be split to fit into 80-character lines (section 8.2.1), and that can cause the first or last character of a line to contain a space character. PGN does not allow that. This is one of the things the PGN Standard author refers to in chapter 5 when he mentions that further work is needed for comments.)

This also means that as the standard is unclear, there's no guarantee that software X will treat comments in the same way as software Y. If you ever need to change software you might run into problems. But as long as you only write for yourself, and keep using the same software, it will probably work without problems.

You probably want to be able to search for text inside your comments: make sure your software allows you to do so, when you place the comment where you want it. Some software (admittedly long ago) failed to search for text in comments that were placed after the final "1-0" / "0-1" / etc. marker of a PGN game.

# Answer
> 0 votes
There's no universal standard, but everyone would expect a regular comment before White's first move to be a summary of the game (since there isn't too much to comment on move 1)

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Tags: analysis, pgn, study
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# Question
Title: Technique for drawing this king and multiple pawns endgame
Given this position with king and multiple pawns per side (white to move):

```
3k4/p4ppp/1p2p3/8/8/1P4P1/P3PPKP/8 w - - 0 26

```

Engines give a 0.0 evaluation. Assuming your opponent plays best moves, my understanding is that it should be reasonably easy also for humans to draw this game. But what's the technique? I know that you need to bring your king to the center, and it also involves opposition, zugzwang and preventing the opponent's king to get behind your lines. Is there a proper, formal way of doing it? I mean something like counting how many pawn moves either side has "before contact".

# Answer
This endgame is not easy at all and indeed Black has to be very careful. As White life is a bit easier since we have a better chance to activate our king, but there's still a game of chess to be played here. Even with few pieces on the board chess is an extremely complicated game. For example, I once maanged to win the following position (as Black, Black to move) to a 1700-rated opponent in a 90+30 game:

8/p4p2/3kp1p1/1p5p/3P4/PP2KPPP/8/8 b - - 0 40

Step 1 of our plan should be moving our king to the 4th rank and keeping it stable there. **1.Kf3 Kd7 2.Ke4 Kd6** could be a reasonable continuation.

Depending on how Black sets up, we'll probably need some pawn moves like a4 or f4 to stop the enemy pawns from kicking our king our of the 4th row. For example Black pawns on b5, e5 and f5 at the same time **could** be bad news In most cases we also want to avoid making unnecessary pawn moves so we can **1**: avoid turning them into weaknesses and **2**: have some tempi to waste in case we reach a potential zugzwang situation. Think of something like the "e" pawns getting traded, Black pawns on f5 and b5, White pawns on b4 and f4, Kings on d6 and d4, and the a, g and h pawns still alive in some square.

But it's hard to define a general "technique" or "method" to guarantee a draw. Instead, each of Black moves will generate several lines where we must calculate precisely. For example Black can try to attack our queenside with something like **1.Kf3 Kd7 2.Ke4 Kc6**. Now White has to choose between a3, Ke5 or Kd4 and I don't think we can come up with a rule to help us decide other than calculate each line as deep our ability lets us (specially since in practical play we won't probably just be trying to hold a draw but also punish Black's most ambitious attempts)
> 1 votes

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Tags: endgame, pawn-endgame, zugzwang, opposition
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# Question
Title: How to avoid the Sicilian after 1.e4 d6 2.Nf3?
I am learning the Pirc Defense as black. I am a bit confused when after 1.e4 d6 white plays 2.Nf3. Are they forcing me to transpose into a Sicilian with 2... c5? I kind of like the Sicilian Dragon, so I guess I could play that (if they play 3.d4). But I am still curious what is the best way to avoid the Sicilian?

```
[FEN ""]

1. e4 d6 2. Nf3

```

# Answer
> 4 votes
White can't force you to play the Sicilian. That is completely your choice. After 1. e4 d6 2. Nf3 there is no reason whatsoever that you cannot continue with the Pirc if you so wish by playing 2...g6.

A more flexible second move for Black would be 2...Nf6 attacking the e4 pawn.

How is White going to defend it? If White plays 3. Nc3 then you can continue with 3...g6 and your Pirc or you can play 3...e5 aiming for a Philidor.

If White defends the e4 pawn with 3. d3 then it looks like White wants to play the Kings Indian Attack. You can't stop this and so you would do well to have some plans what to do against this as it can be quite tricky.

# Answer
> 0 votes
Once you play 2.Nf3 you can't stop Black from going 2...c5 and transposing. You can avoid an Open Sicilian by going for 3.c3, 3.Nc3 or some other alternative.

Why do you need to play 2.Nf3 though? Would 2.d4 work with your repertoire?

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Tags: opening, sicilian-defense, transpositions, pirc-defense
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# Question
Title: What real world benefits are there to playing chess?
What are possible real world benefits to be gained by playing chess? Has this been studied?

# Answer
I think people rapidly bring up the intellectual aspect of the game -- the obvious benefits of studying and improving which should be applicable in other areas, also.

But what is very clear to me, having played as youngster in the days where unbelievably I was able to check into a hotel without even a driver's license and even fly to another city -- my understanding is that an unaccompanied minor would have trouble today doing this -- is how valuable not just learning how to travel at a young age but much more useful was being 15 and interacting with much older people in an adult manner.

Chess provides one of the few situations where people of extremely diverse backgrounds learn to deal with each other in a civilized way.

Without chess, the shocks I experienced upon leaving college to enter the workforce would have been much harder to deal with. Many grads have only dealt with people their own age, professors, and of course their older adult relatives -- a kid who had been to chess tournaments had interacted with multiple adults probably and not always in simply a friendly manner -- there are occasionally problems that anyone who has played live chess would know what I mean -- there are misunderstandings, arguments, even rare fights and knowing how to deal like an adult with such issues means that when they are later encountered at, for example, work, you are at least not completely intimidated.
> 8 votes

# Answer
If you can read French, the former French minister, deputy and mayor of Lyon Michel Noir has written a thesis on exactly that subject in 2002. It is available here.

Its title is :

> Le développement des habiletés cognitives de l’enfant par la pratique du jeu d’échecs : essai de modélisation d’une didactique du transfert.

Tentative translation :

> Development of children's cognitive capabilities by chess practice : an attempt at modeling a didactic of transfer.

Even if you don't read French, its extensive and mostly english-based (but 20 years old) bibliography might be helpful.
> 6 votes

# Answer
The common answers to benefits of \[insert mental exercise here\] include patience, concentration, critical thinking, reduced Alzheimer's risk, etc.

But anecdotally, good chess players are usually viewed as having a higher mental intelligence by the general public, at least in the US (versus, say Rubik's speedcubers). This can be used to your benefit in various social encounters. I've heard cases where National Masters are preferred for non-chess related job openings over other applicants because of this positive stereotype.

Note that I am not arguing that good chess players *have* higher mental intelligence, only that American society tends to *view* chess players that way.
> 3 votes

# Answer
From my own perspective, and nothing more:

Chess teaches studying, patience, strategy, adaptation, spatial relations, perseverance, and more.
> 2 votes

# Answer
Chess or its variants play a major role in rational thinking and brain excercise.

Do a proper physical aerobic excercises and Dhyan Yog (meditation), and take seasonal fruits. It will help you a lot in improving the health and personality.

Play chess and even its variants as a passion and understand the importance of all these pieces in real life. War is the last resort but equat these pieces with problematic entities in life. This can help to understand the meaning and purpose of planning and team management.

Every entity around us holds importance and we should respect this principle.

Chess evolved from Dashpada and new rules are added. It is becoming popular is Asia and even in Africa. Kids are getting benefitted.

Becoming GMs are very very rare and they are very special talented people. We all canot become GMs but can learn from implicit values from this game.
> -2 votes

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Tags: psychology, reference-request
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