# Question
Title: Is there a way to use Stockfish to see tactics that aren't necessarily great?
Basically - I want to utilize an engine to see tactics through the whole game, regardless of whether they're a good move or not. Sometimes, Stockfish may say a position is absolutely winning, but the opponent has a fork which loses the game - UNLESS you play an absolutely perfect sequence of 6, hard to find moves. So, it doesn't even tell you that there was a fork - because the engine assumes you play perfectly, so therefore you are absolutely winning. But, to beginners, it would not be so.

Is there some way to do this, using Stockfish or other?

---

**Edit:** Basically - it would be really cool to "filter" moves by a theme - pin, fork, discovered attack, etc. I think this is really the essence of my question. And then, theoretically, you could go beyond that make the engine have low depth, more lines, etc. But simply increasing the amount of lines it shows you isn't exactly what I'm looking for. (Sorry for my badly phrased question.)

# Answer
Created a script that will detect the following tactical themes.

* pins
* forks
* double check
* undermine

It will read the games in the pgn file. Visit each position in the game and run stockfish at multipv 10 to find non-losing move that generates the said tactics.

Note the code is not optimized.

# Code

```
"""Find pin, fork, double check and underminig moves.

requirements:
    pip install chess
"""

import chess
import chess.pgn
import chess.engine

def detect_forks(init_epd, curmove, currank, curscore, board, wp, bp, event, date):
    """Find move the forks 2 or more pieces.

    Args:
        init_epd: The position in the game.
        curmove: The move from stockfish from multipv analysis.
        currank: The rank of the move from multipv analysis.
        board: The board after executing the curmove.
        wp: White player in the game.
        bp: Black player in the game.
        event: The event name.
        date: The date the event is held.

    Returns:
        A list of positions with fork.
    """
    forks = []

    # The to_square of the move that forks must not be attacked by enemy.
    move_attackers = board.attackers(board.turn, curmove.to_square)
    if len(move_attackers):
        return forks

    prev_board = chess.Board(init_epd)

    # Find the attacked squares from the move.
    attacked_sq = board.attacks(curmove.to_square)
    legal_attacked_sq = []

    # Number of attacked squares must be 2 or more.
    if len(attacked_sq) >= 2:
        # Scan all the squares and pieces on the board.
        for square, piece in board.piece_map().items():
            # If this square is not in the attacked squares, skip.
            if square not in attacked_sq:
                continue

            # If the color of this square is not an enemy color, skip.
            if piece.color != board.turn:
                continue

            # The attacked square should not be defended.
            defenders = board.attackers(board.turn, square)

            # If there is defender, skip.
            if len(defenders):
                continue

            # Store the legal attacked square.
            legal_attacked_sq.append(square)

        # Check if all the legal attacked squares are two or more.
        if len(legal_attacked_sq) >= 2:
            forks.append([init_epd, prev_board.san(curmove), currank, curscore, "fork"])
            forked_sq = []
            for s in legal_attacked_sq:
                forked_sq.append(chess.square_name(s))
            print(f'initepd: {init_epd}, move: {prev_board.san(curmove)}, rank: {currank}, score: {curscore}, forked_sq: {forked_sq}, white: "{wp}", black: "{bp}", event: "{event}", date: {date}')

    return forks

def double_check(init_epd, curmove, currank, curscore, board, wp, bp, event, date):
    """Find move that attacks the enemy king twice."""
    dchecks = []

    prev_board = chess.Board(init_epd)

    # If the to_square of curmove does not check, skip.
    if board.is_check() and len(board.attackers(not board.turn, board.king(board.turn))) > 1:
        dchecks.append([init_epd, prev_board.san(curmove), currank, curscore, "double check"])
        print(f'initepd: {init_epd}, move: {prev_board.san(curmove)}, rank: {currank}, score: {curscore}, checked_sq: {board.king(board.turn)}, white: "{wp}", black: "{bp}", event: "{event}", date: {date}')

    return dchecks

def undermine(init_epd, curmove, currank, curscore, board, pv, wp, bp, event, date):
    """
    Check if curmove is an undermining move.

    curmove, oppmove, oppmovereply ------ pv sequence
    The curmove captures the enemy piece.
    oppmove captures the piece from curmove
    The piece captured by curmove is a defender_pc.
    oppmovereply captures a piece that is defended by defender_pc.
    """
    undermines = []

    if len(pv) < 3:
        return undermines

    pv = pv[:3]  # starts from init_epd

    prev_board = chess.Board(init_epd)

    is_capture = prev_board.is_capture(curmove)
    if not is_capture:
        return undermines

    # Walk the pv starting from prev_board.
    bt1 = prev_board.copy()
    b1 = bt1.copy()
    m1 = curmove

    bt1.push(m1)
    b2 = bt1.copy()
    m2 = pv[1]

    bt1.push(m2)
    b3 = bt1.copy()
    m3 = pv[2]

    # The last move should be a capture.
    if not b3.is_capture(m3):
        return undermines

    if m1.to_square == m2.to_square:
        # The piece captured by m1 is a defender.
        defended_sq = b1.attacks(m1.to_square)
        if len(defended_sq):
            # Loop thru the defended sq, if one of it is captured by m3 then m1 is an undermining move.
            for s in defended_sq:
                if m3.to_square == s and m3.to_square != m1.to_square:
                    pv_san = b1.variation_san(pv)
                    undermines.append([init_epd, prev_board.san(curmove), currank, curscore, "undermine"])
                    print(f'initepd: {init_epd}, move: {prev_board.san(curmove)}, pv: {pv_san}, rank: {currank}, score: {curscore}, undermined_sq: {chess.square_name(m3.to_square)}, white: "{wp}", black: "{bp}", event: "{event}", date: {date}')
                    return undermines

    return undermines

def detect_good_pins(init_epd, curmove, currank, curscore, board, wp, bp, event, date):
    pins = []
    prev_board = chess.Board(init_epd)

    # Loop thru the squares and pieces on the current board.
    for square, piece in board.piece_map().items():

        # Detect a pinned piece of the side to move.
        # The pinned piece is not a king and not a pawn.
        if (piece.color == board.turn and
                piece.piece_type != chess.KING and
                piece.piece_type != chess.PAWN):

            # If this square is pinned by the side not to move.
            if board.is_pinned(board.turn, square):

                # Get the piece type that currently occupies the square, if this piece has no
                # legal move, then it is pinned.
                is_pin = True
                for move in board.legal_moves:
                    if move.from_square == square:
                        is_pin = False
                        break

                if is_pin:

                    # Is the last move pins the opponent?
                    # Takeback the move and check if the square is not pinned.
                    # If it is pinned, the move is not the cause of the pin.
                    # If it is not pinned, the move is the cause of the pin.
                    tmp_board = board.copy()
                    tmp_board.pop()

                    if not tmp_board.is_pinned(not tmp_board.turn, square):

                        # Save the info.
                        attackers = board.attackers(not board.turn, square)
                        defenders = board.attackers(board.turn, square)
                        if len(attackers) >= len(defenders):
                            pins.append([init_epd, prev_board.san(curmove), currank, curscore, "pin"])
                            print(f'initepd: {init_epd}, move: {prev_board.san(curmove)}, rank: {currank}, score: {curscore}, pinned_sq: {chess.square_name(square)}, white: "{wp}", black: "{bp}", event: "{event}", date: {date}')

    return pins

if __name__ == '__main__':
    fn = 'f:/project/pgn/tatamast23.pgn'
    fn = 'f:/project/pgn/2023-pro-chess-league-main-event-regular-season.pgn'
    gcnt = 0
    all_pins = []
    all_forks = []
    all_double_check = []
    all_undermines = []
    multipv = 10

    engine = chess.engine.SimpleEngine.popen_uci(
        r"F:\Chess\Engines\stockfish\stockfish_15.1_win_x64_popcnt\stockfish-windows-2022-x86-64-modern.exe"
    )
    engine.configure({'Hash': 128})

    with open(fn) as pgn:
        while True:
            game = chess.pgn.read_game(pgn)
            if game is None:
                break

            gcnt += 1
            print(f'game {gcnt}')

            wp = game.headers['White']
            bp = game.headers['Black']
            event = game.headers['Event']
            date = game.headers['Date']

            for node in game.mainline():
                board = node.parent.board()

                if board.ply() < 24:
                    continue

                # Analyze this board with the engine. Use multipv 10 to
                # increase the chance of detecting a move that generates
                # a dangerous pin.
                info = engine.analyse(board, chess.engine.Limit(time=0.5), multipv=multipv)

                for i in range(min(multipv, board.legal_moves.count())):
                    score = info[i]['score'].relative.score(mate_score=32000)
                    pv = info[i]['pv']
                    move = pv[0]

                    # The move score should not be lossing.
                    if score <= -200:
                        break

                    # Make the engine move on the board and check if this move pins an enemy piece.
                    tmp_board = board.copy()
                    tmp_board.push(move)

                    pins = detect_good_pins(board.epd(), move, i+1, score, tmp_board, wp, bp, event, date)
                    if len(pins):
                        all_pins.append(pins)

                    forks = detect_forks(board.epd(), move, i+1, score, tmp_board, wp, bp, event, date)
                    if len(forks):
                        all_forks.append(forks)

                    double_checks = double_check(board.epd(), move, i+1, score, tmp_board, wp, bp, event, date)
                    if len(double_checks):
                        all_double_check.append(double_checks)

                    undermines = undermine(board.epd(), move, i+1, score, tmp_board, pv, wp, bp, event, date)
                    if len(undermines):
                        all_undermines.append(undermines)

            if gcnt >= 1000000:
                break

    engine.quit()

    print('pins:')
    for pins in all_pins:
        for p in pins:
            print(p)

    print('forks:')
    for forks in all_forks:
        for f in forks:
            print(f)

    print('double checks:')
    for dc in all_double_check:
        for d in dc:
            print(d)

    print('undermines:')
    for un in all_undermines:
        for u in un:
            print(u)

```

## Sample pins

```
initepd: 3n2k1/p4r1p/1pR1p1p1/5q2/3P4/4QP2/P3N1P1/6K1 w - -, move: Rc8, rank: 2, score: 3, pinned_sq: d8, white: "Praggnanandhaa, R", black: "Erigaisi, Arjun", event: "85th Tata Steel Masters", date: 2023.01.14
initepd: 2Q5/p4nk1/1p4p1/3p2q1/3P3p/5P2/P3N1P1/5K2 w - -, move: Qc7, rank: 1, score: 0, pinned_sq: f7, white: "Praggnanandhaa, R", black: "Erigaisi, Arjun", event: "85th Tata Steel Masters", date: 2023.01.14
initepd: 2Q5/p4nk1/1p4p1/3p2q1/3P3p/5P2/P3N1P1/5K2 w - -, move: Qb7, rank: 2, score: -2, pinned_sq: f7, white: "Praggnanandhaa, R", black: "Erigaisi, Arjun", event: "85th Tata Steel Masters", date: 2023.01.14
initepd: 2Q5/p4nk1/1p4p1/3p2q1/3P3p/5P2/P3N1P1/5K2 w - -, move: Qd7, rank: 4, score: -39, pinned_sq: f7, white: "Praggnanandhaa, R", black: "Erigaisi, Arjun", event: "85th Tata Steel Masters", date: 2023.01.14
initepd: 8/Q4nk1/1p4p1/3p1q2/3P3p/5P2/P3N1P1/5K2 b - -, move: Qd3, rank: 7, score: -26, pinned_sq: e2, white: "Praggnanandhaa, R", black: "Erigaisi, Arjun", event: "85th Tata Steel Masters", date: 2023.01.14

```

The rank is the ranking of move based from stockfish. Rank 1 is the best move based from a given analysis time of 0.5 sec.

The first output line is this.

The move that pins the enemy is Rc8. This is only ranked at number 2 (I have not recorded the top 1 engine move and the actual game move, but this is possible by revising the script) with a score of 3 cp from the point of view of the side to move.

The pinned square is d8. The game is between white: "Praggnanandhaa, R", black: "Erigaisi, Arjun", event: "85th Tata Steel Masters", date: 2023.01.14.

Another line:

```
initepd: 6k1/1p3p2/1R3p1p/3pn3/8/2P1P3/r4PPP/1B2K3 b - -, move: Ra1, rank: 3, score: -108, pinned_sq: b1, white: "Abdusattorov, Nodirbek", black: "Caruana, Fabiano", event: "85th Tata Steel Masters", date: 2023.01.15

```

## Sample fork output

```
initepd: 1k1r3r/ppqb1pQp/2n5/1B6/8/B3PN2/P4PPP/2R3K1 b - -, move: Qa5, rank: 3, score: -28, forked_sq: ['b5', 'a3'], white: "Carlsen, Magnus", black: "Abdusattorov, Nodirbek", event: "85th Tata Steel Masters", date: 2023.01.19

```

The move Qa5 will forked a3 and b5.

## Sample double check

```
initepd: 5rk1/5pp1/8/7p/1QB2P2/1P2q2P/2P2nP1/4R1K1 b - -, move: Nxh3+, rank: 1, score: 0, checked_sq: 6, white: "Pranesh, M", black: "Dubov, Daniil", event: "Pro Chess League Main Event 2023 Regular Season", date: 2023.03.01

```

The move Nxh3 generates a double attacks to the white king.

## Sample undermine 1

```
initepd: 5rk1/2q1pp1p/pnPp1bp1/1p1B4/2r2P2/P1N1Q2P/1PP3P1/3RR1K1 b - -, move: Bxc3, pv: 1...Bxc3 2. bxc3 Nxd5, rank: 1, score: 282, undermined_sq: d5, white: "Foisor, Sabina-Francesca", black: "Deac, Bogdan-Daniel", event: "Pro Chess League Main Event 2023 Regular Season", date: 2023.02.17

```

```
pv: 1...Bxc3 2. bxc3 Nxd5, rank: 1, score: 282, undermined_sq: d5

```

## Sample undermine 2

```
initepd: 5rk1/2q2pp1/R1rp1n2/7p/1pBQ1P2/1P5P/2P3P1/3R2K1 w - -, move: Rxc6, pv: 1. Rxc6 Qxc6 2. Qxd6, rank: 1, score: 174, undermined_sq: d6, white: "Pranesh, M", black: "Dubov, Daniil", event: "Pro Chess League Main Event 2023 Regular Season", date: 2023.03.01

```

```
pv: 1. Rxc6 Qxc6 2. Qxd6, rank: 1, score: 174, undermined_sq: d6

```
> 4 votes

# Answer
If you use Stockfish via some sort of GUI, like Scid, Scid vs PC, Fritz or Chessbase, as most people do, then your GUI will have an option to show not just the best sequence of moves but the best n such. I normally have it set to 2 or 3.

If there are at least this number of legal moves then it will still show this number of alternatives even if only one move (say a queen recapture) is good and the other moves are blunders. If there is only one legal move then it just shows that one move.

I don't know what limit Stockfish places on the number of lines it will give you, but whatever number that is, if your bad but tempting move is in one of those lines then you can get it to show you.

If, say, Stockfish can return its best 10 lines and your bad move is number 9 then you can use this to see it. If your bad move is number 11 or worse then not.

> the opponent has a fork which loses the game - UNLESS you play an absolutely perfect sequence of 6, hard to find moves

In general this type of situation could be detected by setting the maximum depth for evaluation to a low figure.
> 10 votes

# Answer
No. Stockfish is designed to always assume optimal play, so it treats all the moves it finds "equally" without any consideration for difficulty. Keep in mind that engines are a tool to assist analysis, not a replacement for it. It gives you the answers, but you're still the one posing the questions.
> 4 votes

# Answer
Using the "top n lines" approach, one way of finding tactics that "almost" work is to look for moves that are at the same time:

1. Sacrifice material (a light officer or more)
2. Get a flat 0.00 evaluation from the engine.

These kind of moves should be interesting to look closer at, since giving up material should normally mean you are losing. Yet, the machine says you aren't. That means there must be some concrete tactic that works out for you in the future.

Ideally, what this reveals is an attack with you winning in almost every line except for a very accurate defence where the opponent holds the draw. Or the reverse situation, of course, with you defending.

In general, positions with unbalanced material that are still drawn with perfect play should be a perfect example of "tactics that aren't necessarily great". The engine helps you with the "still drawn with perfect play" identification part.
> 1 votes

# Answer
I found something pretty cool, which I guess doesn't answer my question, but it's pretty close in nature:

Lichess has a "Boris Trapsky" bot, in which it makes blunders, or sacs pieces that, if taken, lead to a major advantage, or mate. Doing this against an engine would of course be pointless as with correct play it's just a stupid blunder.

I guess in a perfect world you could somehow use this bot to analyze your own games and find those kinds of moves, which is pretty much what I'm looking for. So in the end, I think it is possible, but requires additional coding, and nothing offers this feature out of the box.

Here's the link: https://lichess.org/study/qDFa6puH
> 0 votes

---
Tags: engines, tactics, stockfish
---


title: Mate in One the Missing King

text:
# Question
Title: Mate in One the Missing King
The post "A mysterious mate in one" made me think of one of my last problems which is also a Mate-in-One with no black King:

```
    [Title "White to move and mate in one"]
    [FEN "1B1NB2K/P2RN3/8/1R6/1P5P/4P2Q/1PP2PP1/8 w KQkq - 0 1"]

```

All the white pieces are there but none of the black ones.
White (at the bottom) to move.
The position is legal, except that the Black King (and the Black King only) is not displayed. Find it - there is but one place.
Mate in one.

# Answer
> 8 votes
Your post is perfectly fine here, my friend. Chess problems and puzzles are on-topic here, and we do need more. All kinds of all sorts are welcome. We just need to bring them here!

I think that out of the 14 open squares on the board, only:

> placing the Black king on both a6 works!

This is because placement on the squares:

> a1, a2, a8, a4, b1, c1, c4, d1, d2, e1, e2, f1, f6, f8, g1, and h6 all result in an illegal position. This is due to the fact that Black either has no last legal move if it is White's turn, or it would've been impossible for the Black king to get around the current White pawn structure. Thus, they are not options at all. This explains the "retrograde-analysis" tag.

Therefore, remaining the square works:

> with the solution checkmate being 1. Rd6#.

# Answer
> -1 votes
8 solutions

1. Bf4#
2. Nf7#
3. Rd6#
4. Ng8#
5. Nf5#
6. Rb6#
7. Rh5#
8. Qe6#

---
Tags: checkmate, problems, puzzles, retrograde-analysis
---


# Question
Title: Petrosian's 9. ... Be7 10. ... Ng8 11. ... Bf8
I am amazed by Petrosian's manoeuvre 9. ... Be7 10. ... Ng8 11. ... Bf8 in the following game:

```
[Title "Benko - Petrosian, Curacao 1962"]
[fen ""]
[Startply "17"]

1. g3 d5 2. Nf3 c6 3. Bg2 Bf5 4. O-O e6 5. d3 Nf6 6. Nbd2 Nbd7 7. Qe1 h6 8. e4 Bh7 9. Qe2 Be7 10. e5 Ng8 11. Nb3 Bf8 12. c4 Ne7 13. Nfd4 Nf5 14. Nxf5 Bxf5 15. cxd5 cxd5 16. d4 a5 17. Be3 Be7 18. Rfc1 O-O 19. Qb5 a4 20. Nd2 Ra7 21. Nb1 Nb8 22. a3 Nc6 23. Nc3 Qa5 24. Bf1 f6 25. f4 fxe5 26. fxe5 Bg5 27. Bxg5 hxg5 28. Qxa5 Rxa5 29. Rd1 Raa8 30. Bb5 Na5 31. Bxa4 Nc4 32. b3 Nb2 33. Rdc1 Nxa4 34. Nxa4 Bh3 35. Ra2 Rf3 36. Rf2 Rxb3 37. Nc5 Rbxa3 38. Nxb7 Rd3 39. Nd6 Kh7 40. Nb5 Rb8 41. Rb2 Rf3 42. Rbb1 Bf5 43. Rb2 g4 0-1

```

These three moves (9. ... Be7 10. ... Ng8 11. ... Bf8) seem to violate a lot of opening principles and undevelop his pieces. Are they really good moves? What can we learn from them?

# Answer
> 6 votes
9 ... Be7 is a normal developing move preparing to castle next move.

10 ...Ng8 reflects a change in plan given white's change to the pawn structure. On f6 the black knight was doing a good job attacking the e4 pawn. When it moved to e5 attacking the knight, forcing it to move, that changed. The only two squares that don't lose the knight are h5 and g8. On h5 the knight has no moves and no prospects. That leaves just g8 but raises the problem where is the knight going to go?

11 ...Bf8 solves the problem of the knight. It allows the knight to relocate to the active square f5 via e7.

> What can we learn from them?

This is a classic example of a good player having the flexibility to change plans in response to the opponent's moves even at the cost of undeveloping one or two pieces. One of the most common mistakes of intermediate players is to play "formula" chess where the same opening moves are banged out regardless of the opponent's moves.

---
Tags: opening, development
---


# Question
Title: What would be some great books that clarify the positional concepts of the Queen's Indian Defence from the Black side?
I've been looking for some books that explain how to play the Queen's Indian Defence. These books don't have to be recent or anything.

# Answer
In my library I've "The Queen's Indian" by Yrjölä-Tella, Gambit Publications, 2003.

The lines showed might be outdated now but it seems to me that the authors have made an effort of explaing the various strategic motifs behind the various alternatives.
> 1 votes

---
Tags: opening, books, queens-indian
---


title: Brain fog when playing chess

text:
# Question
Title: Brain fog when playing chess
I've been playing chess from many years but started playing more from past few month. I only play 3 minute blitz games, have rating around 1350 in chess.com and 1700 in lichess, have played few thousand games till now.

I observed that sometimes my brain just doesn't seem to work and am unable to find even the simple moves fast. I won't be able to think few moves ahead. I keep losing games continuously till my rating goes down by 100s of points. This happens for days together. And sometimes, it magically happens that my brain works quick, analyses and find the best moves naturally without any strain.

Does anyone feel the same when playing blitz games? How do you bring yourself into 'that sweet spot' where the brain is active and quick?

# Answer
I think what you are experiencing is fairly common. I find that I have games that i feel like an absolute legend, able to come up with creative solutions and just not making any mistakes.... then there other games where i hang pieces , miscalculate large trades and just can't get things to click.

I think its partially due to fatigue though. If you are playing game after game after game, especially with blitz , theres little time to think and your brain starts to fatigue and you start making mistakes.

I think the best way to do deal with this just recognizing when you are starting to get fatigued and take a break. I find puzzles are really good for helping me with this. I usually do puzzles for half an hour, take my time try to calculate things out a little. then have a cup of tea, then good to go.
> 14 votes

# Answer
Fatigue is likely a factor. It's common in older players like myself and with playing a lot in a short time. I'm worst in the afternoon games 3 & 4 of a one-day tournament.

But it also may be akin to *stage fright*. I play best against familiar players in our club or online with friends. I miss many good shots in a tournament, against strangers or with players I'm supposed to beat ( because they're lower rated ). Your opponent may also be affected. Years ago I drew a game against our States previous Senior Champion. He was about 500 ELO better than me. I was relaxed with little expectation of winning. He seemed intense, made an impulsive move, and I won.
> 8 votes

# Answer
1700 on Lichess is good, but not amazing - it puts you in the top 45% of people who play blitz on Lichess. It's the sort of platform from which you can decide to dedicate time, effort, and hardship, to excel and maybe aim for a title one day, but it's also still very reasonable to chill out there and just enjoy yourself.

If you're not looking to reach for those heights yet, or at all, don't focus on the rating points. Play blitz until you're not having fun, or you need to go do the washing up/go to work. If you are winning and having fun, the points you're gaining aren't what matters. If you're losing and having fun, the points you're losing are irrelevant.

With that out of the way, I have personally found that it's mostly familiarity and sleep. For a period, I completely shirked bunch of responsibilities (don't do that) and played the heck outta bullet, used the "analyse your mistakes" feature on lichess, looked up openings, and slept whenever I felt tired, with no alarm to wake me up. During this time, not only did I have a great deal of fun, my rating went up quite a bit, and I think I improved (as my rating stayed there).

Now I've been playing mostly atomic for several months, and not spending nearly as much time playing standard chess, and sleeping in such a way to line up with a full time job which very much destroys me. My standard play feels very much like you describe your "brain fog".

So long as you've having fun, just stick to it, and make sure you're sleeping right. It's also worth making sure you're eating right, too, but I have no experience with poor diet's effect on my psychology 'cause I always eat reasonably well.
> 5 votes

# Answer
You might consider the possibility of a real illness. What you describe is a symptom of hypothyroidism, which means that you have an inactive thyroid gland. Another symptom of this condition is feeling cold and shivery. I speak from experience. It can be treated with thyroxine tablets.
> 4 votes

# Answer
Try playing blitz for 25 minutes and meditating for 5 minutes. This helps to make sure that your mind isn't overloaded and can rest. For more info check here.
> 0 votes

# Answer
"Brain fog" is very common. Especially when you put too much energy towards one thing and having strong desires and expectations of improvement. Basically, what's happening is you are just having a moment. You're brain is now in digesting mode and kind of taking in everything you have learned. Kind of like ...DOS mode.

Take advantage of that and just go do something else. You'll know when it's time to get back to it. Sometimes this can last a day or maybe a week but believe me, you won't forget a thing.
> 0 votes

---
Tags: psychology, blitz
---


title: Anti-Tactics Chess Puzzles?

text:
# Question
Title: Anti-Tactics Chess Puzzles?
Many websites (such as chess.com) provide chess tactic puzzles and I am wondering about the value of "anti-tactic" puzzles. By anti-tactic, I mean a position where if I make a careless move, then my opponent has a tactic to checkmate in a few moves or win some material forcefully. So my task is to find the best move that stops my opponent's ideas.

My questions:

1. Are these "anti-tactic" puzzles valuable?
2. Where can I find such puzzles?

# Answer
Dan Heisman wrote a book *Looking for Trouble : Recognizing and Meeting Threats in Chess*. I'd rate it as one of my better chess books & I believe it's still available as an ebook.
> 3 votes

---
Tags: tactics, puzzles, prophylaxis
---


# Question
Title: My opponent won despite his king having no legal moves
My opponent won despite his king having no legal moves. Why?

# Answer
this beginners question keeps being posted again and again (mods, please insert link here):

"Stalemate" is NOT "king has no legal move".

"Stalemate" is "stalemated king is not in check" AND "no piece of the stalemated side has a legal move".

In your case, it is true that your king is not in check and has no legal move, but your pawn on h6 (h7?) still can move.
> 4 votes

---
Tags: checkmate
---


title: Basics in chess programming

text:
# Question
Title: Basics in chess programming
I'd like to understand the basics behind chess programming. Would you please recommend any resource to start from? I have a good understanding of programming in C/C++ and Java. Thanks, Giulio

# Answer
> 1 votes
David N. Levy wrote/compiled several books on computer chess basics. They're a bit old, but as the basics don't change much, they are usually a good place to start. Those I remember in particular are

D. N. Levy & M. Newborn: How computers play chess

D. N. Levy: Computer Chess Compendium

www.bookfinder.com can be a good place to find out-of-print books.

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


# Question
Title: Is there fiction dealing with retrograde chess analysis?
I am interested in retrograde analysis problems, where the question usually is: 'What was the last move made?' or 'Where did the piece stand on the board before it fell from the table?' etc. Currently I know of only two occurrences of retrograde chess analysis to have found its way into fictional literature. One is Arturo Pérez-Reverte's "The Flanders Panel", the other is Raymond M. Smullyan's "Chess Mysteries of Sherlock Holmes". The latter is not even a real novel, but retrograde chess problems presented in story format, so I am not sure whether I should have included it in my list.

Do you know of any other fictional work using retrograde chess problems as an important element?

# Answer
> 22 votes
There's also *A Happy Solution* by Raymond Allen. It's a short story (under 6000 words), but quaint. It appeared in *The Strand Magazine* in 1916.

The puzzle featured in Allen's tale was posted here in Chess.com's forums:

```
[FEN "2BK3N/NP1P1PPb/P4P2/3p1q2/1Q1P1b2/1pB1p1p1/p1p2pp1/1kr4r w - - 0 1"]

```

While Chess.com's puzzle is set up for Black to force mate, it is also the board that Kenneth Dale did a retrograde analysis on. The game was between Sir James Winslay and Lord Churt. When a banknote was found to have been pilfered, Churt's secretary Gornay was remembered to have been watching the game, but no one could vouch for how long. Gornay's innocence appeared inviolate, as he was also remembered to have made several remarks on some of the past moves of the game at its conclusion:

> "If the play was rather eccentric sometimes, I must say it was bold and dashing enough on both sides," Gornay commented. "For instance, when Lord Churt gave up his knight for nothing, and when you gave him the choice of taking your queen with either of two pawns at your queen's knight's sixth." He turned to Churt. "Possibly you might have done better to take the queen with the bishop's pawn instead of with the rook's."

After this, the missing note was found in the wrong envelope, and Dale suspected that Gornay may have been the one who had moved the note, in order to frame Dale in case of the note's being found.

> "Was he in the library all the time you were playing?" Kenneth asked.
>
> "I can't say that," Churt replied. "I don't think he was. I didn't notice particularly. But I am positive that he did not enter or leave the room while I was standing looking at Winslade's move, and he must have been there when Winslade offered his queen and when I took it, because he was commenting on those very moves after the game was finished, and suggesting that I might have done better to take with the other pawn. You heard him yourself."

Dale later proved that Gornay could have figured out those previous moves simply by looking at the resigned game, and therefore had been free to leave the room and do his dirty work while the game was still underway.

# Answer
> 10 votes
There is also 'The Chess Mysteries of the Arabian Knights' by Raymond Smullyan which you probably already know.

# Answer
> 4 votes
There is *The Flanders Panel*, a crime novel written in 1990 by best-selling Spanish author Arturo Pérez-Reverte.

The plot revolves around an old painting, where a chess position between two players appears incidentally in the background. Upon close inspection the position reveals mysterious things that I won't spoil.

# Answer
> 4 votes
There is also a russian book by author Yuri Barskiy called "Eight Blind Witnesses" (original name "Восемь немых свидетелей"). It is a series of short Sherlock Holmes stories, each having Holmes solving an actual crime, with chess games playing the central role.

# Answer
> 3 votes
```
[TITLE "chess position from The Flanders Panel book"]
[FEN "1nb5/pp1p4/PRP5/pR6/k1K1P3/2P5/2qP1P2/1NrnQB2 w - - 0 1"]

```

For the retro logic in the "The Flanders Panel" to work, there are two assumptions required: (1) there were no promotions (2) the black queen was royal, i.e. could not have been left exposed to attack. The solvers also assume that it was Black who moved last: perhaps there is some clue in the painting (e.g. Ferdinand of Ostenburg pushing the chess clock :D). If you accept those conditions, then the retro logic works out OK, in what is a well-written & atmospheric historical thriller.

It is **so much better** than the corresponding composition in the movie of the book, renamed "Uncovered", and starring Kate Beckinsale. The diagram is:

```
[TITLE "chess position from Uncovered movie"]
[FEN "2n1r1k1/bQ2p1r1/p4p1q/6pp/1P5P/R5PK/2BR4/4N3 w - - 0 1"]

```

The retroanalysis is simply bonkers, but most of the analysis concerns the forward play, in what is initially a balanced position, but which is thrown away by the "expert" player representing White in a series of moves not much better than those in "Alice Through the Looking Glass".

The total blunder 1.Ra5? is played in the movie (Stockfish prefers 1.Qd7!) 1...g4+! 2.Kh2! Qxd2+! 3.Qg2? (3.Ng2!) 3...Qxb4? (3...Qxe1!) 4.Qc6? (4.Ra1!) and Stockfish rates the position -9.9.

In one of the chess scenes (in the park) the diagram position is actually wrong, with bKa8 instead of g8, and wQ missing!

Amazing that in a movie which is ostensibly about a chess position, that no-one bothered to invest $50 in a competent chess player to sort the thing out properly!

---
Tags: fiction, retrograde-analysis, studies
---


# Question
Title: In the Queen's Gambit Declined, why is 5.e3 so much more popular than 5.Nf3 after 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.Bg5 Be7?
To me it seems that both moves transpose into each other in almost all lines, so why is e3 so much more popular? Some statistics from the lichess masters database:

* 5. e3: 3,289 games (72.5%)
* 5. Nf3: 877 games (19.3%)

What is the meaningful difference between these two moves?

# Answer
> 5 votes
As the other answer points out 5. e3 is more flexible but there is a very concrete reason too; After 5. Nf3, Black can play h6 6. Bh4 dxc4 7. e3 c5 and now we are heading to an isolani type of position that tends to drawish positions and may not suit everybody's style:

```
[Title ""]
[fen ""]
[Startply "21"]

1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. Bg5 Be7 5. Nf3 h6 6. Bh4 dxc4 7. e3 c5 8. Bxc4 cxd4 9. exd4 (9. Nxd4 Bd7 10. O-O Nc6 11. Nf3 O-O 12. Rc1 Nh5 13. Bxe7 Qxe7) 9... Nc6 10. O-O O-O 11. a3 b6 12. Qd3 Bb7 13. Rad1 Nd5

```

Moreover, if Black instead of 6... dxc4 plays 6... 0-0, the main move for White is e3. This means that by altering the order (first Nf3 and then e3) White has to study the shown line above, whereas in 5. e3 Black has to study additional lines like 5... 0-0 6. Rc1 or 6. cxd5, so 5. e3 is a more pragmatic choice.

# Answer
> 0 votes
My notes indicate I wondered the same thing when studying the QGD. In his book *Playing 1. d4 d5* Ntirlis, for the **Bg5 QGD**, prefers move order 4. Nf3 Be7 5. Bg5 . This is simply his repertoire. Later, p 29, he discusses **Delaying Nf3 or e3** . "Against defensive schemes like the Tartakower and Lasker, it makes some sense for White not to develop his knight at f3 so soon." Soon he changes course and states "Another idea for White is to develop the knight while delaying e2-e3. This is known as the Uhlmann Variation." I'm not an openings guru, but my short answer is that 4. Bg5 Be7 5. e3 is the traditional line of the Lasker. ( Tradition = peer pressure from dead people.) *The art is long and life is short*.

---
Tags: opening, queens-gambit-declined
---


title: Examples of Computers failing

text:
# Question
Title: Examples of Computers failing
Are there any positions where computers would play a bad move, but we humans know of the existence of a better move?

By “computer” I mean standard engines such as Stockfish, at full power.

**Edit:** By a “bad” move I mean a move that changes the "shape" of the game.

# Answer
A good example is the following position from a study by William Rudolph (which is also in the posting linked to by ASTA):

```
3B4/1r2p3/r2p1p2/bkp1P1p1/1p1P1PPp/p1P4P/PPB1K3/8 w - - 0 1

1. Ba4+! Kxa4 2. b3+ Kb5 3. c4+ Kc6 4. d5+ Kd7 5. e6+ Kxd8 6. f5

```

The problem here is that White seems to be completely lost no matter what they do, but it is in fact possible for them to lock up the position by giving up even more material.

In general, fortresses are still difficult for standard top engines. It is not hard to come up with positions that current top engines do not understand. It is, however, very difficult to achieve such positions in real games with any reliability.

It is also worth noting that there are engines that have specialised fortress-detection code. For instance, the Stockfish fork *Crystal* solves the position given above in a matter of seconds. However, these engines are weaker than the top engines in normal positions.
> 8 votes

---
Tags: engines
---


title: Why is this a “Brilliant Move”?

text:
# Question
Title: Why is this a “Brilliant Move”?
I don’t understand why chess.com says this is a “Brilliant Move”? Can someone explain please?

# Answer
> 5 votes
Whites bishop on g5 is hanging, after Bxg5 Nxg5 Qxg5 black is up a piece. However this would remove the defense of the c7 pawn allowing for Nxc7 by white forking the king and the rook on a1 leading to the winning of the exchange. Chess.com grants brilliancies when a move loses material but either maintains or creates an advantage.

# Answer
> 0 votes
The move 8. e3 moves the pawn from e2 and allows the queen a clearer path to black's (undefended) knight on h5. Piggy-backing of Bansel's analysis 8... Bxg5 9. Nxg5 Qxg5, black is now open to the Nxc7 fork. However, if black doesn't play 9... Qxg5, the knight on h5 is now hanging because the queen on d1 has a clear path to h5. Even worse for black, That h5 knight has no square to retreat to, in part to the f4 square being defended by our hero pawn on e3.

In short, 8. e3 indirectly threatens the h5 knight and forces black to either concede it, or give up the fork/exchange.

---
Tags: engines, analysis
---


# Question
Title: In ChessBase, how can I force the deep analysis function to analyze a specific variation?
For example, say I want to run deep analysis on 1.d4, but I'd like to ensure 1.d4 h3 is looked at, how can I achieve this?

From the chessbase manual: "Variations that are in the notation at the start of the analysis are never deleted and are always analysed, unless they are the results of a previous Cloud Analysis."

I've tried starting the analysis with 1.d4 h3 in the notation, but as soon as I hit deep analysis, h3 is removed from the notation and not looked at (and no, it's not a result of a previous cloud analysis).

Does anyone know how to achieve the behavior I'm after?

I'm on ChessBase 17 with the latest update.

# Answer
> say I want to run deep analysis on 1.d4, but I'd like to ensure 1.d4 h3 is looked at, how can I achieve this?

In previous versions of Chessbase (I still use Chessbase 6) the way to achieve this kind of thing was to construct your own opening book containing only the opening lines you wanted it to look at and tell Chessbase to use this book.
> 2 votes

---
Tags: chessbase
---


# Question
Title: Who are the top 10 youngest players to reach a FIDE standard rating of 2200?
In age order of achieving the rating, who are the 10 youngest players to reach 2200 standard FIDE rating? Prag and Karjakin obviously feature, but who else?

# Answer
> 7 votes
Chess by numbers posted this on twitter earlier today: https://twitter.com/ChessNumbers/status/1638634335480995841

---
Tags: rating, statistics, records
---


# Question
Title: Material that doesn't actually hang (Training)
(One of) My chess kiddie (U8!) is an aspiring grandmaster (I would lean that much out of the window), but we are just a small club. Still, I'm a life long chess kiddie trainer and want to give him the appropriate training to keep him from running away to the local big club as long as possible.

Methinks he plays a bit greedy. Maybe a good trait on his age level where his opponents hang pieces left and right, but I want to give him some training material "Think before you grab". A typical tactic from this area is the "Bxh2, g3, oopsie" manouvre, even Fischer fell for that. Or the Qxb2-and-you-get-disowned.

Can you give me a reference specialized to this theme, be it book or online? (For example, I'm thinking of the chapter "Greed" in Rowson's "7 Deadly Sins" book.)

EDIT: Here is an example I made myself, devoted to LxB-and-gets-jailed.

# Answer
To "*keep him from running away to the local big club as long as possible*" is morally wrong.

Forwarding him to another learning environment is **not** an oopsie Bxh2 and g3 wins your student. Such a view is wrong.

It is instead much better to see yourself as "*the material that doesn't hang*".

Ask yourself, are you material that doesn't actually hang? Will a "*life long chess trainer*" still be there for him, should this student leave for another club?

"*Think before you grab!*"

By all means, support him joining and enjoying as many training opportunities as he likes, support his family, offer to cooperate with all his agents, find solutions that are designed to help his case, etc, over years. This is where you shine. Granting motivation and options. No laudations in return.

You just continue to not hang.

As for referrence, indeed, the chapter "Greed" in Rowson's "7 Deadly Sins".
> 2 votes

# Answer
You could create any puzzle that lures a piece (rook?) away to back-rank mate. Similarly, you could also create one that, if taken, loses protection for any other piece in the Mid-game and Opening. This could lead to thinking before taking any piece at all.

Make sure you play a few games with him to create this type of situation, and see if this is actually *applied* to any chess games they play.

This is an example (FEN):

```
1r4k1/5ppp/8/8/4B3/4R1P1/5P1P/6K1 w - - 0 1

```

https://lichess.org/editor/1r4k1/5ppp/8/8/4B3/4R1P1/5P1P/6K1\_w\_-\_-\_0\_1?color=black

White does Bb7. If Rook Takes Rxb7, white can back-rank mate with Re8, and loses the win of 7 points.

```
2kr2nr/ppp3pp/q4pb1/3P4/5n2/NNQ2B2/PPP2PPP/R3R1K1 w - - 0 1

```

https://lichess.org/editor/2kr2nr/ppp3pp/qb3pb1/8/4Bn2/NNQ1P3/PPP3PP/R3R1K1\_w\_-\_-\_0\_1?color=black

In this puzzle, White plays Nc5, attacking the queen at a6. Black plays Rd1. It seems like Black is giving a free rook. If Rxd1 happens, Black will do Ne2+, forking a king and queen. After taking the queen Nxc3, the checkmate threat will be ended.
> 0 votes

---
Tags: tactics, training, reference-request
---


# Question
Title: What are qualitative differences between different engines playstyles, and also human playstyles?
I remember GM Daniel Naroditsky commented that you can tell that you're playing a computer if you do calculations and none of your plans work because specific moves that were done 3-4 moves ago start mattering a lot (can't find the reference).

Does this statement apply to all modern top engines?

Are there other ways one can distinguish between different engines and humans (multi-way comparison)?

I'm only interested in differences that can be detected by a (possibly superGM) human, especially during a game.

I am particularly interested in differences between different engines. This includes (but is not limited to) differences that don't distinguish them from human players.

# Answer
First of all, the phrasing "you can tell" is **far** too assertive, because it is very hard to convict somebody based on his play in a single game. Think of the recent cheating accusations of Magnus Carlsen against Hans Niemann. There was extensive analysis and thousands of people investigated this single game by multiple means - and while there are some clues (e.g. (un-)likelihood, suspicious interviews, ...) there is no proof that Hans Niemann really cheated instead of having superb opening preparation and a really great day, playing at his best.

Magnus Carlsen had exactly the same feeling that GM Naroditsky described: **Getting outplayed**. You would have the same feeling when playing against GMs (without them cheating, of course). They understand the position better and look deeper into the variations and therefore appreciate nuances in the position (moving to square x instead of square y, because in some obscure variation, it might take away some of your options or give them more). The important part is, that the playing strength differential must be very large in order for it to happen that a player gets the feeling that he doesn't get **any** play **at all**. As GM Naroditsky is a very strong player who wouldn't easily allow others to take all his options from him, he would always have some ideas against other human players (who, playing not perfectly, would leave him at least some of them in the majority of the games).

Of course, every engine that clearly is above human level (3300+) is capable of outplaying even the strongest GMs; it is not a question of 'style'. And if that happens, they become suspicious (even though it happens occasionally in clean tournament games too, of course).

Other indications that humans can use to substantiate suspicion are

* people taking the same amount of time for every move (most likely 'beginner cheaters' / kids entering the moves into a program).
* frequently playing top (~3) engine moves (even non-obvious or "non-human" ones, as judged by the strong player), but occasionally playing serious inaccuracies not matching the previous quality of play (that even much weaker players would likely not make) or not matching the plan (most likely 'post-beginner' cheaters who try to conceal themselves by playing on their own for a few moves or deliberately making mistakes in order to impede detection).
* thinking on very obvious moves (e.g. recaptures, only moves, follow-up-moves)
* people playing pretty meekly suddenly recovering from a completely lost position by generating enormous piece activity and counterplay
* people first outplaying their opponents and obtaining a winning position, but struggling to convert even trivially won games (e.g. massive material advantage without technical difficulties) in time trouble.

All that being said, human observations are almost never enough to justify a cheating accusation. Big platforms like chess.com or lichess use sophisticated machine learning algorithms to discover cheating, that capture much more complex features and patterns than those that can be judged by humans without assistance. Such features include technical parameters (e.g. mouse movement, active browser windows, ...). And even then, usually, multiple cheating games are needed to turn suspicion into "certainty".
> 1 votes

---
Tags: engines, style, super-grandmaster, chessmaster
---


# Question
Title: Can you suggest book references on chess theory?
as stated in the title I am looking for structured textbooks on chess. I have followed chess.com lessons and I have a rough idea of tactics (forks, pins, skewers, sacrifices, etc) but I feel like I am missing something.

Is there any book that seriously expose the theory of chess, like an academic text would do?

# Answer
Almost, every book of chess is about chess theory. There are millions!

One fantastic collection is Yusupov Complete Series: https://www.qualitychess.co.uk/products/13/195/yusupov\_complete\_series\_in\_hardcover/

Arthur Yusupov is one of the greatest chess players of all time. Moreover, this collection won several prizes for its high quality.

My advise would be to start with book#1: ***Build up your Chess 1.***

The same collection is available on Chessable that is a website that uses a very friendly format. Also, you can access it in any part of the world immediately. Additionally, www.chessable.com gives you a 30 day trial: https://www.chessable.com/the-fundamentals-1-build-up-your-chess/course/19145/

I have returned several books that I did not like without a problem.

If you prefer the classic format, the editorial of Yusupov gives you an exceprt. You can find it in this link: https://www.qualitychess.co.uk/ebooks/Build-up-Your-Chess-1-exceprt.pdf

https://www.qualitychess.co.uk/products/2/16/build\_up\_your\_chess\_1\_-\_artur\_yusupov/

Good luck in your chess journey!
> 2 votes

---
Tags: theory, books, mathematics, recommendations, reference-request
---


# Question
Title: Who was Wright, purportedly the best player in the Australian prison system?
I read a true crime book by Mark "Chopper". It states the best player in the Australian prison system was named Wright. Does anyone have any more information on this person, such as their first name?

# Answer
> 4 votes
His name was Robert Wright, a convicted murderer who died in a 1987 prison fire.

---
Tags: history, books
---


# Question
Title: Who is the oldest player ever to beat a reigning world champion?
Per title. I'm interested in all time controls. This record isn't in the Wikipedia list of Chess records.

Related: Youngest Player to beat a reigning World Champion? which asks for the youngest player.

# Answer
> 5 votes
The best I could find:

* Former World Champion Emanuel Lasker at 67 years, 8 months, 1 day defeating Max Euwe in Nottingham (1936).

---
Tags: records, world-championship, trivia
---


title: Opening Theory in Hexagonal Chess?

text:
# Question
Title: Opening Theory in Hexagonal Chess?
Is there any opening theory in Glinski's hexagonal chess (rules here)? If so what are some standard openings?

# Answer
I tracked down a book, *First Theories of Hexagonal Chess* by W Glinski published by Hexagonal Chess Publications in 1974 and managed to buy a second hand copy. That lists several openings:

1. King's Gambit Accepted
2. King's Gambit Declined
3. King's Knight Opening
4. Rook's Opening
5. Queen's Flank Opening 6.King's Flank Opening
6. Four Pawn Opening
7. Centre Pawn Opening
8. Queen's Pawn Opening
9. Knight's Opening

Here are the moves given for:
**King's Gambit Accepted**

1. g6 fg 2. Nhf3 Be9 3. Nik5 Rig8 4. Bxk7
(2... h6 3. Bi6+ NxB (3... Bh8 4. BxB+ RxB 5. Qxk7) 4. QxN Bh8 5. Ql4 Rh9)
(2... Ng9 3. Bd4 e6 4. Nxg6)
(2... Bd6 3. Bi5 Ng9 4. Bl4 Rg8 5. Bxg6 Qd8)
(2... g5 3. fg Ng9 4. Bd4 e6 5. Rg3)
> 2 votes

---
Tags: opening, theory, chess-variants, hexagonal-chess
---


# Question
Title: Have any Australians played Carlsen OTB, other than Smerdon and Smirnov?
There was Smerdon vs. Carlsen (2016) 1/2-1/2, and now there is Smirnov vs. Carlsen (2022) 0-1. I'm not aware of any other games between Australian players and Carlsen.

**Question**: Have any Australians played Carlsen OTB, other than Smerdon and Smirnov?

ABC News suggests there have been other games:

> Queensland Grandmaster David Smerdon is **one of the few Australians to have faced Carlsen over the board**, holding him to a draw at the 2016 Chess Olympiad in Azerbaijan.
> ABC News, 2021.

I'm guessing people might be downvoting because it's basically impossible to eliminate the possibility that there were Carlsen vs. Australian-player undocumented games played e.g. in a bar. I'm mostly just interested in what's available in databases. I personally don't own a database, and I'm not sure of an efficient method to check online databases for "Australian player". The answer might very well be "there are no others recorded" (cmgchess's comment seems to suggest this), but I don't know.

# Answer
> 3 votes
Zhao Zong-Yuan played Carlsen in the first round of the 2007 World Cup, losing both games.

---
Tags: history, master-games, carlsen, otb-chess
---


title: Can the White King capture the bishop?

text:
# Question
Title: Can the White King capture the bishop?
Here is the satuation Black: King(b7), rook (a8), Bishop (e8,b4), pawn (c7,e6,f7,g7) White: King(c4), rook (g4), Knight (f3), pawn (b2,c2,f2,g3)

It is white to move.

```
r3b3/1kp2pp1/4p3/8/1bK3R1/5NP1/1PP2P2/8 w - - 0 1

```

In this case, can the white king (c4) capture the black Bishop (b4)?

# Answer
A more complete answer:

* Is it legal? Yes, it's a legal king move and the king is not in check afterwards.
* Is it good? No, as after Ra4+ followed by Rxg4 White is a whole rook down instead of a light piece.
* Is it relevant? Hardly, Black simply keeps a large winning advantage (after best move Rxg7) anyway, so you can as well take on b4 and pray to Caissa to strike your opponent with chess blindness :-)
> 11 votes

# Answer
The problem of course is the Ra4+ and the x-ray attack on the white rook, resulting in its loss, so that would be a bad move.

Depending who you play, you may be able to play white pawn B3. If ignored, then the Ra4+ will either not be played, or will result in the loss the of the black rook as it moves to A4.
> 1 votes

# Answer
The black bishop on b4 is unprotected, so it's free for the taking.

Unfortunately, that's not the best move according to Stockfish.
> -1 votes

---
Tags: advantage
---


title: Who is this quote from?

text:
# Question
Title: Who is this quote from?
My memory tells me that this quote:

> Whenever someone says that he is better than me, I checkmate him

is from Capablanca. But I haven't been able to find it. So maybe it isn't from him or that quote never existed.

Do you know this or a very similar quote like this one and who said it?

# Answer
This is a quote by Emanuel Lasker. I found the source to be The Adventure of Chess, a 1950 book published by Edward Lasker. The quote given is:

> In mathematics, if I find a new approach to a problem, another mathematician might claim that he has a better, more elegant solution. In chess, if anybody claims he is better than I, I can checkmate him

Edward says Emanuel once told him this.
> 5 votes

---
Tags: identify-this, quotations
---


# Question
Title: Is there any positional assessment that includes a factor for how difficult it is to play the correct moves?
As I understand it, current positional assessments by computers evaluate a position based on optimal play by both players from this point.

i.e. a trap moves that bait an opponent into making a mistake (even a really subtle one!) have no additional value because the computer assesses the position on the assumption that the opponent *doesn't* make that mistake.

That seems reasonable; playing in the hope that the opponent makes bad moves isn't strong tactical play.

But I assume that means that the converse is also true:

If I have a single winning line full of incredibly obscure counter-intuitive moves, that only a GM would have any hope of finding, and any deviation from that line leads to the whole thing immediately collapsing ... then that position is evaluated as winning.

Are there any evaluation programs/frameworks that attempt to account for that "you're ahead but only if you make a series of very specific moves" concept? Essentially "you're ahead, but you've made the position *very* unstable, and thus hard to play".

# Answer
When it's hard for humans to find a very specific series of moves, it's simply because they lack strength in tactical aspect of chess. There is no such thing as *"you're ahead, but you've made the position very unstable, and thus hard to play"*.

That being said, if I understand what you are saying, you want to understand when it's hard for humans to play. To find the answer, we need to understand how humans generally think in chess.

Humans mostly evaluate positions based on material imbalance and King safety. There are also other factors which may influence a human's understanding of a position, such as the amount of space being controlled, bishop pair, passed pawns/connected passed pawns, isolated pawns, doubled/tripled pawns, minor piece activity, how well the rooks are positioned, etc. When it's hard for humans to understand a position is when none (or barely any) of these imbalances are present despite one side being significantly better (based on computers). This situation arises when one side simply has no useful moves. In such positions, if the winning side fails to understand how helpless his opponent is, he may fail to punish his opponent. I believe this case relates to the strategical aspect of chess.

To finally answer your question, no, there are no tools that detect how hard it is for humans to properly evaluate a position (it would be very interesting to see this functionality by chess engines, though!)

In regard to tactical pattern difficulty, I'm not aware of any tool that has the capability to understand how hard the moves are to find for a human. Chess.com has an interesting algorithm that highlights hard-to-find moves with blue exclamation marks, but I don't know how relevant or helpful that would be for you, and we have no access to the code of this algorithm as chess.com is not open-source, so we can't know exactly how it works.
> 1 votes

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Tags: positional-play, evaluation
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# Question
Title: Why had T. Petrosian never used Hippopotamus Defence?
The Hippopotamus Defence is considered one of the most solid defences and GM Tigran Petrosian is considered one of the most defensive players. Apparently, Petrosian knows about Hippopotamus, but why did he never use this super-defensive defence? I thought this opening suits his playing style perfectly.

# Answer
> 4 votes
The Hippo is passive, but definitely not solid.. Black is allowing White to set up the way they like without posing any real challenge.

There are simply too many ways for White to get a lasting advantage, and given that time controls in Petrosian's time were longer than today, I can't think of any situation where it'd be worth it to play the Hippo.

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Tags: opening, grandmaster, defense
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# Question
Title: Can I become a GM by playing 100 games per day without studying books, strategy, etc?
Some things in life you learn by simply doing, not just doing it, but doing it a lot. Practice makes perfection. I don't believe no-one is born a GM. Even Kasparov had to practice a lot.

So has anyone have experience with just playing many, many games to practice? Did it help you improve or it just cannot work that way?

# Answer
> 6 votes
By spending that much time on something per day, you will inevitably become very good at what you practice!

Unfortunately, what you'll be practicing is moving pieces around on a chess board, based on the kind of thinking process you have at the moment. You'll be great at doing exactly that.

What it's very bad for, is *changing* how you do something. And that's what's needed to improve in chess -- figuring out what you're doing wrong, and then figuring out how to stop doing that. Having repeated the same wrong thought pattern thousands of times will make it much harder to get rid of the bad habit.

As of the time I'm writing this, user "german11" on Lichess has played 531,069 games there. Most of them (about 414k) are bullet games. His bullet rating is 1104 right now.

Note that the learning science discussions about "10,000 hours of practice to become an expert" and so on are about *deliberate* practice. Not just any kind of rote repetition will work.

# Answer
> 4 votes
# You *can*, but you probably won‘t.

First of all, becoming a master or getting even a 2000+ (ELO-) rating, is a very hard task and most chess players never achieve that – and some of them play and study a lot, so at least playing a lot of games cannot be a recipe to become a GM. Well, but maybe you are kind of a genius and are able to master lots of skills to become a master only by playing.

There are most certainly better methods of getting better, at the very least you should analyse your games and find your mistakes – if able do that with a better player, not with a machine. I would also recommend playing less games which a larger time control. Doing lots of tactics, studying pawn formations and attacking schemes, typical positions arising from the openings you play, endgame positions etc. could also pay off.

Furthermore, by only playing I doubt you will master opening and endgame skills very well. The theory there is totally complicated and it should be vary hard to learn it just by playing (without even analysing the games!). (While tactics and typical play in "your openings" can be – to some extent – learnt by "just playing").

# Answer
> 4 votes
Let me play devil's advocate here (since everyone seems to take the negative position) and say **yes, you absolutely can.**

But, and this is a big but (no pun intended) the games you play have to be "good" games, and it will not be enough to simply play them, but rigorous analysis must also be done on each game that is played.

The absolute truth of the matter is that any student, with enough motivation, a cheap computer with a decent processor, some (free) chess software and either a lot of talent or a lot of time, can become an IM or even GM. This is something not many players will admit, because it seems to subvert all the chess-related purchases they might have made.

In the past, it was necessary to hire a tutor, or read books and other chess literature, to keep up-to-date on opening theory and to learn chess. Today, with the advent of powerful chess engines and game databases, much of this is obsolete. Furthermore, I would argue that chess books are not only outdated, but outright inefficient when compared to the alternatives. These are bold claims, so let me try and support them with a plan of action which is bereft of any chess literature and focuses only on games.

**The Plan**

1. **Don't play 100 short games a day**, this is a waste of time. **Play 1 long game (90 minutes or more)** against a moderately strong computer engine and spend the rest of the time doing analysis
2. You will lose pretty much every game you play (if the computer is set to its highest level) but **you must not get discouraged** or change your style of play to beat the computer (i.e don't play closed positions solely for the reason that computers are bad with them). This is where motivation and discipline will determine whether you really benefit from this method.
3. In every game, **focus on a single thing and try to improve it**. Initially the biggest problem might be gross blunders, hence you should do a blunder check on every move you play to prevent such blunders from occurring.
4. You should **try to create a thinking algorithm**, a step-by-step process or checklist which helps you to make decisions over-the-board and then use this algorithm for every move (until it becomes habitual and automatic). Steps might include things like the blunder-check above, or deciding whether the position is tactical (requires intensive calculation) or positional (requires sound planning and positional understanding). This is the only thing where it might be faster (not necessarily better) to read up on, instead of building it yourself, since efficient thinking systems already exist that were created by very successful players (Capablanca, Nimzovitch, Tal etc.).
5. Analysis of your games should be done to **figure out weaknesses or lapses in understanding**. The easiest way to do this is to look at positions **where you spent the most amount of time**. A computer must be used to keep yourself objective and grounded in the concrete, but is used only to *check* your analysis, not to **replace** it. (Most computer engines have the option to analyze your annotations and almost all give a point score for every move, take advantage of these options).
6. **Play in tournaments and OTB games**, record them, and analyze them the same as your other games. These games are more valuable, because you can actually win them once in a while and because they are games outside of a controlled environment (i.e not in the comfort of your home).
7. You will undoubtedly improve the most by **focusing on your own games**, but for a change of pace you might want to **analyze a collection of games by a strong GM or favorite player**. You should do this by playing guess-the-move from the winning side, making annotations for moves you guess (correctly or incorrectly). Then check the game with a computer engine (you'd be surprised with how many mistakes you find, both in your own analysis and in the moves of the GM's). You can also use these games to figure out the thinking algorithms of the masters.

If you actually stick to the above recommendations, I really think you'd make significant progress. Much more so than if you spend an equivalent amount of time reading a book. The reason is because passively reading something is very inefficient, compared to actively learning through difficult training games. Why is reading/chess literature still popular? Mostly because it gives a false sense of accomplishment and because its enjoyable. Ask yourself if the last chess book you read gave you a significant boost to your rating or chess understanding. Ask yourself how much you actually *remember* from the book, whether the concepts or games or annotations, and how much of it has actually influenced your OTB play.

The method above is not merely my own conjecture but is inspired by the training system developed by Botvinnik (there is a portion I left out, concerning physical exercise, but I think that's self-evident), who emphasized long-time-control training games and thorough analysis for chess improvement. The emphasis on thinking algorithims comes from the research done by de Groot.

Ultimately the final verdict, is yes, you can improve in chess through just games. But few have the dedication, discipline and motivation to do so.

# Answer
> 1 votes
Of course you will improve from just playing, however getting to GM level without studying 1 book is almost unheard of, maybe some world geniuses but otherwise not possible. There are things in chess you can not learn or realize they exist without getting taught about them.

However... You can get to Master level with a lot of playing, I played chess for 2 years straight and all I did was play it 8 hours a day... Achieved master level with minimum learning from books (mainly openings only and some tactics explained by Daniel King). However, I had to research a lot more to achieve a higher (which I haven't yet, got college :( )

Overall, you can get to Master level, anything like IM and GM level require some legit learning.

# Answer
> 1 votes
Anecdotally I know a few people who have reached 1800-2000 level without serious dedicated study, just by being smart people who already have strong talent in logical thinking in other areas like math, programming, logic puzzles, etc and knowing very basic tactics and concepts like control of the center, pawn chains, basic endgame strategies, etc. This is a far cry from GM level but it is pretty impressive nonetheless.

However there is no point in not doing training to improve seriously. Before this century you had to pay a chess coach and read books to get strong analysis, but nowadays everyone has access to computer engines and tons of free lessons online. All you need is a smartphone and internet connection, and it doesn't even have to be a powerful smartphone. This is probably why so many strong younger players who spend lots of time on a computer have appeared.

# Answer
> 1 votes
It seems impossible in my view.

Books, videos and other learning material contain methods and conclusions that have taken hundreds of years to discover, understand and present.

It seems highly unlikely you will arrive at similar conclusions by playing your own games.

Also, to become a GM, you have to meet the current GM requirements. That will take a lot of effort and you will meet hard competition.

It is one thing to know something in theory. It is another thing to put it into practice during a real game, over the board, against a human opponent.

How to play a tournament is a whole challenge in itself, on top of playing chess.

You will probably learn something from your games. But you will learn way faster and better if you know what you are trying to do and how to put the outcome in a bigger context.

There is another element to this. In life, there are many different mountains you can try to climb. Becoming a chess GM is one of them. If you don't know, from deep within, why you are climbing this mountain and feel a deep drive in your entire being, then you will likely give up.

What is GM? It is a title. It is a reward for something, but what is that something? What are you doing and why?

I did not try to become a GM. I tried to become a player that makes anyone worried across the board. From the library player to the world champion. Once I got to that point, it seemed good enough.

Nowadays, I am no longer interested in competition. I want collaboration. To build something together. To meet and share ideas and insights.

Peace,

Rauan

# Answer
> 0 votes
As it turns out, you *can* become better than a GM purely from playing games. That's what AlphaZero did - it learned completely from self-play.

The caveat, of course, is that you have to play a **lot** more than 100 games a day. To get an idea of the number of games required, the AlphaZero derivative Leela Chess Zero is one of the strongest chess engines around, plays roughly a million games a day, and has played ~1.5 billion games against itself.

100 games/day is not nearly sufficient to become a GM.

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Tags: grandmaster, best-practice
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# Question
Title: What are the most popular Russian-language chess community websites?
What are the most popular Russian-language chess community websites for high-level chess discussion?

# Answer
> 1 votes
ChessPro is the most popular. Chess.com is next. Chess24 is third.

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Tags: online-chess, websites
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# Question
Title: How are FIDE rating changes calculated for a tournament across rating periods?
If I play a FIDE-rated tournament with games from the April 30th to May 2nd, will the ELO changes be calculated using my April rating, my May rating, or April in April and May in May?

# Answer
> 1 votes
The rating is calculated using all his results as if they were played with your starting rating.

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Tags: fide, rating
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# Question
Title: How to set custom start position in GNU Chess?
I could not find this in the GNU Chess manual by searching, although I might be overlooking it, under a different name.

What I am seeking to do with GNU Chess is quite simple: Specifying the position of every single piece on the board, for both players, and deciding who starts after that. I'm currently reading a beginner's book on Chess, as I know nearly nothing about it, and would like to follow the tutorials, which suggest to start with particular positions with a chess computer or advanced player, and figure out how to survive.

The optimal feature would be having the possibility to keep those starting positions in text files, so that I can reuse them and modify them.

# Answer
> 3 votes
The manual can be found on GNU Chess's website. To set a custom position, use the setboard command followed by the FEN string of the game position.

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Tags: engines
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# Question
Title: Is better to lose a knight or a bishop when taking a queen/rook
I don't completely understand how knights and bishops (according to chess.com) have the same "piece value." If I were to be taking a queen (or rook), should I give up my knight or bishop? So in conclusion, is a knight or bishop more important?

# Answer
> 8 votes
Knights and bishops have very similar value so it's not possible to make a general assessment of which one is better. The specifics of the position will always dictate which piece to prefer. You may want to learn about strategic themes like good/bad bishops (specially in endgames).

Either way, since rooks and queens are almost always stronger than knights and bishops, it won't matter much and the trade will be worth it no matter what. The difficult question is when to trade a bishop for a knight and vice-versa.

# Answer
> 2 votes
It depends on what portion of the game. Towards the beginning, when there are many pieces, the knight is better as it can hop over pieces. Towards the end, when there are less pieces, the bishop is better as it has a larger range than the knight (can move more squares in one direction). This is a general rule, keep in mind that this isn't always the case.

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Tags: strategy, knights, bishops
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# Question
Title: Black beginning (specifically, the Immortal)
By CPT (or better: the Chess version thereof) if a game is opened by Black, you can transpose it to the standard version (by swapping board, colors and move rights) and there is no visible difference. I somewhere read that the Immortal indeed was played this way. I googled a bit, it seems that the convention that White begins was first proposed by master Löwenthal, i.e. is not *that* old at all!

Can a historian help out about a) when "White moves first" was canonized worldwide (pre-1st version of FIDE rules?) and b) if the Immortal indeed was played with Black moving first?

# Answer
> 2 votes
This is only a partial answer to your first question. It was common practice, but not a rule, by 1862. It appears that the first time this was made a rule in a major tournament was the year 1880.

# Answer
> 2 votes
Partial answer:

In Staunton's Chessplayer Handbook, published in 1847, the rules section (Chapter V, The Laws of the Game, starting p35) describes many nuances, even about odds games or the consequences of failing to say "check", but omits to say which side should play first.

However, all the games are presented with White playing first. This seems like a form of evidence for Staunton, who writes at the beginning of the first example (chapter IX, p51-52):

> In this game, as in all the analyses that follow, the reader will be supposed to play the White Pieces and to have the first move, although, as it has been before remarked, it is advisable for you to accustom yourself to play with either Black or White (...).

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Tags: rules, history, famous-games
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# Question
Title: What Are Some Good Tools for Learning Chess Openings?
I have an online rating of 1900, and about 30% of my lost games have been lost because I clearly messed up in the opening, so I want to focus on my openings to improve my rating further.

I am looking for any specialized tools that would help me study and learn openings (preferably free ones). I know about Chessable, but I'm not a big fan of that website, because I don't particularly like the way MoveTrainer works (I find it boringly repetitive), and the courses are rather expensive. I'm looking for a tool that is more compact/simpler, that is specifically made to learn openings. I love Lichess studies, but there are only a limited amount of community studies available, and most of them don't go too much into details.

Are there any websites/programs you would recommend that would help me learn openings? Are there any specialized tools available for this task, or should I simply get into Chessbase and make my own studies/databases with it? I should note that I am aiming for an online rating of 2200.

# Answer
Chess.com and liChess have extensive opening libraries which you can use for study, but if you're looking for more detailed explanations of the ideas in the openings and not just moves, you should look to opening books. The FCO (Fundamental Chess Openings) book is a good one for a more shallow look at the openings, but if you want to go in depth on a particular opening there are individual books specific to nearly every opening. Beyond this, the youtube channel "hanging pawns" has a lot of higher level opening videos.
> 2 votes

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Tags: opening, training, study
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# Question
Title: What are the normal hourly rates for coaching with a National Master (US)?
As a National Master offering private chess lessons to individuals in the United States, what are the normal hourly rates?

# Answer
> 1 votes
It seems that a good answer to your question is that the fee depends on the instructor.

In my perspective, fees for chess lessons are between $0 and $500 per hour. Instructors who charge $0 are volunteers who love to do something good for humankind and do NOT need the money. Instructors who charge $500 are teachers in high demand, have a big number of customers, and have access to very rich people.

Some instructors charge $5 because they live in countries with low living costs. Moreover, they are from non-English speaking countries. Additionally, if they charge $5 per hour because they do not have too many customers. A more common fee for online instructors from non-English speaking countries is $15-25.

Instructors who live in the United States usually charge $50-100 per hour. This has a lot of sense because in some areas of the United States if you work in the fast-food industry, you start with $17 per hour. A good guess is that to make a living in the USA as a chess instructor, you need to charge $100 per hour and have enough customers who have the financial resources, and the willingness to consider lessons from that instructor a good investment. Only people with an excellent income can afford to pay $100 per hour. That is the reason why books and videos are so popular as an alternative, or as a complement, to chess tutoring that is expensive.

Lichess.org and chess.com have a section for instructors. You can find several names there. Also, if you are looking for someone in your area, look into craiglist.org. In addition to that, there are many websites that offer teaching services, just Google it.

Something interesting is that a national master and even a instructor without a chess title can charge the same or more than a grand master. The logic behind this is that a grand master will play better but not necessarily will be a better instructor. One excellent example is Steve Giddins, who is not a grandmaster, but he is a formidable writer and lecturer. One of his former students is grandmaster Matthew Sadler. Steve Giddins is a FIDE master.

Good luck in your chess journey!

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Tags: online-chess
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title: Why do people play a/h3?

text:
# Question
Title: Why do people play a/h3?
I am very low rated in chess (900 chess.com rapid) and when I play against higher rated players I often see moves like h3, a3 from white, and the equivalent from black. I don't understand why someone would play these moves, as it doesn't exactly take the centre or develop pieces, threaten pieces etc. I often see it in the opening as well, when you are supposed to treat the tempo valuably and not throw it away with useless pawn moves.

# Answer
> 6 votes
@OP: Newcomers have a tendency to overgeneralize sensible hints.

a3/h3 is bad if

* it wastes time (*main reason*)
* it gives a hook for a pawn storm
* it generally weakens your castling position
* thousand other reasons having nothing to do with the general hint.

a3/h3 may be good if

* the reasons in the other answer
* it makes luft for the castled king
* thousand other reasons having nothing to do with the general hint.

# Answer
> 2 votes
Some reasons why this might be done (answer assumes h3, flip it all for a3):

1. To prevent Bg4
2. To prevent Ng4 and allow stabily for a bishop on e3
3. To keep more pieces and cram the opponent
4. To prepare for g4

# Answer
> 1 votes
You say

> I don't understand why someone would play these moves, as it doesn't exactly take the centre

These moves may be played to control the center.

For example, h3 may be play to prevent a Bishop landing on g4 which would pin a Knight on f3 weakening the knight's control of the center.

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Tags: opening, middlegame
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# Question
Title: Has simultaneous partial queen pinning, besides mutual queen pins, happened in a master game?
In a 3+0 blitz game, this humorous position arose. Have such mutual partial pins, wherein both players pin the others queen to their king, occurred in master games?

```
[FEN "r3k2r/1ppb1ppp/p2bqn2/2p5/8/2NN1QP1/PPPP1PKP/R1B4R w kq - 0 1"]

1. Re1 Bc6

```

# Answer
Yes, many times. I won't list them all as that would be far too long, but here are 2:

1. The game between Mikhail Tal and Bent Larsen at the 1965 Candidates Tournament. In this game, both players had their queens partially pinned, with Tal's queen pinned to his king by Larsen's bishop on g7, and Larsen's queen pinned to his rook on d8 by Tal's queen on d5. The game continued with both players trying to find ways to break the pin and improve their position.
2. The game between Anatoly Karpov and Viktor Korchnoi at the 1974 Candidates Tournament. In this game, both players had their queens partially pinned, with Karpov's queen pinned to his king by Korchnoi's bishop on b7, and Korchnoi's queen pinned to his knight on d7 by Karpov's bishop on g4. The game continued with both players trying to maneuver their pieces to break the pin and gain an advantage.
> 2 votes

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Tags: history, famous-games, queens, master-games, pins
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