# Question
Title: Quintuple repetition and the FIDE's 2014 rulebook revision
How does the new quintuple-repetition rule work, please?

To be clear: my question does not concern how likely the rule and its cases are to arise in practical play, but rather just what the rule is, in cases in which it might theoretically apply. Technically precise answers which (i) illuminate possible misunderstandings and (ii) consider edge cases merit extra appreciation.

Also, if you happen to know: Have authors, masters and/or tournament directors concurred (to the extent to which they care) in the meaning of the new quintuple-repetition rule? Or does the rule as written admit technical ambiguity?

References:

**UPDATE: EXAMPLE**

In light of @dfan's comment, an example:

```
[Title "White to move, illustrating sect. 9.6"]
[FEN "2b2rk1/5ppp/8/8/8/8/5PPP/2B2RK1 w - - 0 1"]

1. Bb2 Bb7 2. Bc1 Bc8 3. Ba3 Ba6 4. Bc1 Bc8 5. Bd2 Bd7 6. Bc1 Bc8 7. Be3 Be6 8. Bc1 Bc8

```

Drawn? Why or why not?

# Answer
> 3 votes
The commenters seem to agree unanimously—and please pardon the necessary formalism!—as follows: Quintuple repetition arises when, and only when, the position on the chessboard is the same after moves *n,* *n+2,* *n+4,* *n+6* and *n+8* for any nonnegative *n,* where *n* need not be an integer but *2n* is indeed an integer.

For example, quintuple repetition arises if the position is the same after 31.5, 33.5, 35.5, 37.5 and 39.5 moves—that is, if the position is the same after White's 32nd, 34th, 36th, 38th and 40th moves. Whether positions after 38, 38.5 and/or 39 moves happen also to repeat earlier positions is irrelevant to the rule.

The example given in the question is indeed a draw by quintuple repetition.

# Answer
> 4 votes
First note that your link to Geurt Gijssen. Arbiter's Notebook. is broken. ChessCafe.com have put almost all their stuff behind a paywall.

The purpose of this rule and of the related 75-move rule (after 75 moves with no captures or pawn moves the arbiter can / must step in and declare a draw) are for the benefit of arbiters. In summary they are the "I've got a home to go to and a warm bed waiting for me" rules. The key point here being that these two rules do not require a player to make a claim but instead the arbiter can intervene to stop the game.

Your example is not a draw under the rule. Here is how it works:

White's alternate moves must be identical. Black's alternate moves must be identical. For 5 consecutive, alternate White's turns the position must be identical. For 5 consecutive, alternate Black's turns the position must be identical.

If that gobbledygook sounds confusing here is an example of a drawn game under the new rule:

1) Nc3 Nc6 2) Nb1 Nb8 3) Nc3 Nc6 4) Nb1 Nb8 5) Nc3 Nc6 6) Nb1 Nb8 7) Nc3 Nc6 8) Nb1 Nb8 9) Nc3 Nc6 10) Nb1 Nb8 11) Nc3 Nc6

Note that after Black's 4th move White could have claimed a draw under the 3-fold repetition rule and after White's 5th move either player could claim a draw on their turn.

If either player deviates from the strict repetition then the conditions are not fulfilled. For instance if White's 3rd and 4th moves are Nf3 and Ng1 then the strict sequence required for the satisfaction of the rule is broken.

Note that the rule says "for at least five consecutive alternate moves by **each** player". If it said "either player" instead of "each player" then the position and sequence in question would be a draw. But the example fails because it is only identical before alternate White moves and not before alternate Black moves.

Since 3-fold repetition draws can only be claimed when the moves are recorded they cannot normally be claimed during rapid and blitz games. The new rules allow the arbiter to intervene and stop the game provided he has witnessed and noted the moves and continue with the next round or go home to bed.

30/12/2014: There were two International Arbiters at our club annual rapid championship last night. I asked one of them and he was very clear. The rule:

> the same position has appeared, as in 9.2b, for at least five consecutive alternate moves by each player.

according to him means that after 5 alternate white moves the position must be the same in the meaning of 9.2b and after 5 alternate black moves it must be the same in the meaning of 9.2b and that this sequence of moves must be consecutive i.e. the first repeating black position must come immediately before or immediately after the first repeating white position and not part way through the sequence.

PS It's probably worth noting the answer he gave to a supplementary question.

Question: What happens if after one player wins through resignation / checkmate / flag fall it is discovered that there was an earlier 5 fold repetition? Should the result be changed to a draw?

Answer: Emphatically no. Just as the 3 fold repetition rule is for the benefit of the players, they may choose to claim by it or not at the specific time the incident occurs, so is the 5 fold repetition rule for the benefit of the arbiter, he may choose to enforce it or not at the time the incident occurs. He may not enforce it retrospectively. The win stands.

Edit: Well, it seems that the IA I consulted was wrong. Hidden away in section 6.2a of the FIDE Handbook it says this

> A move is also completed if: 1.the move ends the game (see Articles 5.1.a, 5.2.a, 5.2.b, 5.2.c, 9.6a, 9.6b and 9.7)

9.6a and 9.6b are the two new draw rules, 5-fold repetition and 75 moves with no captures or pawn moves. So, they are elevated by this throw-away clause to the same level as checkmate, stalemate, resigns and agreed drawn. The arbiter has no more choice than he does with checkmate, etc.

# Answer
> 2 votes
During the FIDE refresher course for International Arbiters, it has been strongly recommended to apply this rule very strictly. Which means that IA are strongly encouraged to change an already signed result if it is later discovered that a quintuple repetition has occurred.

After a quintuple repetition, the game is drawn without any formality, no claim is required. The game is also implicitly over, meaning that all that happens after is irrelevant. For the 75 moves draw, if there is a mate, it will prevail.

If the result reported by the players is anything other then a draw, this means that both players have, wilfully or not, signed a wrong result. This situation is governed by Article 8.7

At the conclusion of the game both players shall sign both scoresheets, indicating the result of the game. Even if incorrect, this result shall stand, unless the arbiter decides otherwise.

# Answer
> 2 votes
In the Jan 2018 Laws (and indeed the previous version too, but that's history) the rule is replaced with:

> 9.6.1 \[The game is drawn if\] the same position has appeared, as in 9.2.2 \[Draw by Repetition\] at least five times.

And the game ends immediately, like mate, pat, dead position & 75 moves. So this issue is resolved. I do feel that, little by little, the FIDE Laws are improving.

# Answer
> 1 votes
The only question is whether the same position has occured ( = the FEN notation would be the same) multiple times ( = five different # of moves apply to the same position). Nothing is said about move sequences.

# Answer
> 0 votes
The rule is there to stop players playing on repeating the position ad infinitum. Threefold repetition has to be claimed by a player, an arbiter can step in to end the game in a draw after fivefold repetition.

# Answer
> -2 votes
this seems to be quite academical, because after 6... before intending Bc8 which would get into a threefold repition of position the black player may request a draw.

---
Tags: rules, fide, draw, fivefold-repetition
---


title: How good can I get just by playing?

text:
# Question
Title: How good can I get just by playing?
On blitz 3|2 I am rated around 1000. I love playing the game and usually I play with players around my level. I try to play against slightly better players. Assuming I am not reading chess books or otherwise get a training besides playing the game, how good should I expect to get?

# Answer
> 14 votes
And an interesting question you pose as to how good you could become playing 3|2.

The 3 min plus 2 second increment you play means roughly say a move rate overall of about say 6 seconds per move for an average game of 50 moves. You try to always play slightly stronger players, excellent idea, so assuming you are not getting trounced ie at least breaking even I think you will progress perhaps to 1200 to 1300. Games will be won or lost mostly by one or two move combinations or simple oversights by you or your opponent. Not an issue if you are playing mainly for the enjoyment of chess.

But if your real focus is to become a strong player this is a different matter. To put your question into perspective consider other endeavours. Would you expect a carpenter who only built small wooden boxes in five minutes to be able to build you a good house? A computer programmer who only spent six seconds on each line of code to become an excellent programmer without further study or deeper reflection?

If your main goal is to improve you need to start playing longer games and to play through master games that are annotated. You will notice a more rapid improvement in your games though it will require some dedicated work. Don't go overboard on opening theory, just aim to get a playable position out of the opening.

But it is in the end-game that playing strength really shows so make some serious effort in this phase of the game and you will improve dramatically. After studying endings you will find your middle game will start to improve as well because you now are aware of which endings to aim for and which to avoid.

Before the internet era I did not have much chance to play over-the-board so I played correspondence chess. This long style of chess forces you to carefully analyse your moves and to study openings and endgames otherwise you could be stuck with a bad position for a year or two! When I did get to play OTB I did regularly get behind on the clock but managed to bowl over quite a few strong players including some with titles.

# Answer
> 8 votes
My own belief is that you can't get good at chess without studying. There are millions of players stuck in the 1300-1400 range who play tens of thousands of games over the course of years but never improve.

# Answer
> 7 votes
Improving at chess for many people means obtaining a better understanding of different aspects of the game, such as: how to play different types of openings, different midgame plans and how to undertake them an defend against them, and how to play endgames well. Underpinning all of the strategies and knowledge is a level of competence in tactics. It is this wider understanding that stronger players draw on when playing blitz that enables them to make good moves quickly.

Playing blitz 3+2 is giving you plenty of practice in spotting tactics and ideas quickly. Unless you are spending some other time thinking about the games, you are limiting your potential to that single improvement method. And there is nothing wrong with that if you enjoy the games. However, if you want to achieve your full potential, it will almost certainly help to think about different aspects of the game for more time than you have per move at blitz. This might be by playing some games at a slow time where you can have a proper think about options, by reviewing some key positions with a friend or a computer program to understand how different choices might play out, or by some reading.

If you don't fancy the idea of any of that, there's nothing wrong with continuing to learn by doing. Choosing to play against people slightly better than yourself is sensible in that regard - on the occasions they beat you they will often use ideas that you can understand and learn from.

You asked in a comment above how to benefit from analysis of your own games. One way is just to notice the questions that you ask yourself during the game, and occasionally follow them up. For example, you may feel during a game that you have a great attack but the opponent wriggled out of it. Looking at it afterwards with a computer will either tell you how you could have closed in on checkmate, or confirm that the attack was unsound. Then you will have either some improved ideas about how to conclude an attack or a slightly improved feel for whether an attack is worth launching. Other common questions are "where did I go wrong in this game", or "how do I deal with this opening line that people keep beating me with"? But follow your own interest.

# Answer
> 3 votes
My rating was 1400 on chess.com three months ago. After that I stopped playing. But I got this rating by playing and analysing my games only. So you can get upto this level without reading or taking any training. About rating like 1700 or 1800 I don't know much about them as I never got upto that level.

Hope it helps.

# Answer
> 0 votes
I don't think there is a general answer to this that will fit everyone. A really astute individual or a savant will be better at spatial relations and interpreting the basis of the game than the general run of players. Players like Morphy or Capablanca, of whom it was said that chess was his native tongue, would fit that description. A keen observer would understand that the game is a dynamic balance that must be upset in one's favor to win. Tactics utilized to win material, basically spatial relations, may come more naturally to some than others. I taught myself to play as a youngster in 1948 but always attacked the king directly at the expense of material and didn't grasp the concept of gaining a material advantage first until I was given odds in a game with an Expert teacher. Then a light bulb went off in my head and I immediately understood that I had to win material before going after the king. Understanding of strategy took longer and relied mainly upon book learning from a manual. That's just a shortcut to avoid all the mistakes that would go into experiential learning, which for the normal person would take many, many games. I really don't think limiting yourself to quick play as you mention is going to let you understand some of the more profound aspects of the game either. Fischer said that blitz kills ideas. It's more reflex than understanding. I personally would suggest longer games for that purpose, along with some book study to shortcut your learning by trial and error. And playing stronger players is alway desirable for progress. If you're very clever, you could probably advance into the average ranks by play alone, but unless you're exceptionally gifted, going much further isn't likely to happen without some study.

# Answer
> 0 votes
As others have indicated, without extra work, you will hit a ceiling beyond which you won't move. Where the ceiling will be will depend on how smart you are. I've only been playing and watching GM games, some videos, never really seriously read any books and I've been stuck at about 2000-2100 for about a decade. But take Morphy, for example - he mostly relied on his natural ability (there was not much theory then) and experts agree that he played at a GM level.

# Answer
> 0 votes
It really is rather sad that nobody has mentioned going over the game with your opponent afterwards. Of course with so much chess being played online these days this is often difficult, but it forces you to try and explain what happened, and to invent your own theories that can be compared with what you find in books. Not everyone is able to learn from this. For some it is just a continuation of the combat. Avoid these people.

---
Tags: training, beginner
---


# Question
Title: Knowing when to play Nc6 vs Nbd7 in the Najdorf Sicilian as black?
I've been studying the Najdorf Sicilian for some time, and I generally have a good idea of where to develop my pieces to. My light and dark square bishops typically end up on e6 and e7, respectively. I'll castle short and my rook will ultimately end up on c8. One thing I struggle with, however, is deciding whether to play Nc6 or Nbd7, and what elements make one choice more attractive than the other.

I understand that each move has its own strengths and weaknesses. Nc6 gives the king knight the ability to retreat to d7 at some point with prospects of pushing the f-pawn. It however blocks off the semi-open c file that is typically pointing at the white king. Nbd7 supports the knight on f6, but also takes away its ability to retreat to d7. Another benefit is that it keeps the c file clear for black's rook. Nbd7 also blocks the queen's defense of the d pawn.

Consider the following position I faced against the obscure Adams attack variation: `rn1qkb1r/1p3pp1/p2pbn1p/4p3/4P1P1/2N4P/PPP1NPB1/R1BQK2R b KQkq - 1 9`

Engines slightly prefer Nbd7 in this position to Nc6, though my intuition would tell me to play Nc6 before considering Nbd7. How would you go about deciding whether to play Nc6 or Nbd7 in this situation? Also, are there any good games that are instructive on this subject?

# Answer
Well it all "depends" on the position, but in the given example, Nc6 is a better option as it has a possible outpost on d4 or b4 and with the rook on c8 it will also be doubly defended. It can even be re-routed to f6 if required which would be almost impossible from d7. Nbd7 does block the defense of the d6 pawn. BTW , I saw a study somewhere that countering the najdorf the d6 pawn is to be targeted therefore it is suggested not to make it a liability in the first place ( of course this might be valid in high level games only). Here is a study where majority games I saw played Nbd7 but I am not a GM and can't quite follow the reasoning. If your opponent castles long then definitely put the knight on d7.
> 3 votes

# Answer
A better answer might be neither.

Chess Tempo says nbd7 loses 100% for black nc6 will win you about 1/3 of the points available considering ties h5 comes out even in the end and b6 nets half but with more chances not to lose but less to win
> 0 votes

# Answer
@David Chopin

As I noted the first time both lines are inferior.

h5 would be better.

And to @Scounged - the games were played by 2200++ rated players and there were many more games than you say.

The results based on data based on GM play speaks for itself.

The real question is why play that line at all when 2Nc3 avoids it.
> 0 votes

# Answer
It all depends. There is no rule. What is your preferred strategic plan? Which move supports that best?

What is the opponent doing? Which move would best counter what they are doing?

If your intuition says one thing then do that until you see why it was not as good as an alternative.

If you are not at least IM if not GM level it really wont make any difference to the outcome of your games.

How often does this happen?
How many people let you play the najdorf at all?

In the grand scheme of things how often does this come up in your games and is that enough to obsess about such a minor choice?
> -1 votes

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


# Question
Title: Are there any cloud engine services solely 'pay per use'?
I'm looking for a chess cloud engine service where I only have to pay for the time I use.
I thought chessbase.com provides that, but you have to get a premium membership first (as far as I understand). Nextchessmove.com and chessify.me require subscription as well.
Is anybody aware of an alternative that just bills per time used?

# Answer
Lots of them let you pay zero per use.

Download your own program and you only pay once.
> 1 votes

---
Tags: engines
---


# Question
Title: Getting wrong results in perft stats with checks and mates
The perft count works well after testing with many positions from epd files from the web

Now I want to see some perft stats like this one: https://www.chessprogramming.org/Perft\_Results, from the initial position

But I'm getting bad results for checks and mates, in the wiki says in the initial position in the depth 4 there are 8 mates but I get that result in the depth 5, same for the the depth 5 in the wiki says 347 but I get that in the depth 6 and it should be 10828, what I'm doing wrong?

Here is the program output with perft to depth 6: https://pastebin.com/3DSVn9UZ

Here is the code:

```
typedef struct perft_stats_s {
    uint64_t captures;
    uint64_t en_passant;
    uint64_t castles;
    uint64_t promotions;
    uint64_t checks;
    uint64_t discovery_checks;
    uint64_t double_checks;
    uint64_t checkmates;
} perft_stats_s;

typedef struct perft_data_s {
    perft_stats_s stats[1];
    uint64_t nodes;
    uint64_t elapsed;
} perft_data_s;

void UpdateStats(move_t move, bool is_capture, bool in_check, board_s *board, perft_stats_s *stats)
{
    if (in_check)
    {
        uint64_t checks = attacksToKing(board);
        if (popCount(checks) == 1) {
            ++stats->checks;
            uint64_t to_sq = bb_sq(TO_SQ(move));
            if (to_sq != checks) {
                ++stats->discovery_checks;
            }
        }
        else {
            ++stats->double_checks;
        }
    }

    if (is_capture)
        ++stats->captures;
    if (MoveType(move) == MT_EP_CAPTURE) {
        ++stats->en_passant;
        ++stats->captures;
    }
    if (MoveType(move) == MT_CASTLE)
        ++stats->castles;
    if (MoveType(move) >= QUEEN_PROMOTE)
        ++stats->promotions;
}

uint64_t PerftStats(uint8_t depth, bool in_check, board_s *board, perft_stats_s *stats) {

    ASSERT(checkBoard(board));

    move_t list[MAX_MOVES];
    uint8_t count;

    if (in_check)
    {
        move_t *first = list;
        move_t *end = generateEvasion(board, list);
        count = end - first;
    }
    else
    {
        count = generateAllMoves(board, list);
    }

    uint64_t nodes = 0;
    uint8_t m;
    move_t move;
    bool is_capture;

    if (depth == 1)
    {
        for (m = 0; m < count; ++m)
        {
            move = list[m];
            is_capture = board->pieces[TO_SQ(move)] != EMPTY;
            if (!makeMove(board, move))  {
                continue;
            }
            bool inCheck = isInCheck(board);
            UpdateStats(move, is_capture, inCheck, board, stats);
            ++nodes;
            unmakeMove(board);
        }
        return nodes;
    }

    for (m = 0; m < count; ++m)
    {
        move = list[m];
        is_capture = board->pieces[TO_SQ(move)] != EMPTY;
        if (!makeMove(board, move))  {
            continue;
        }
        bool inCheck = isInCheck(board);
        uint64_t new_nodes = PerftStats(depth - 1, inCheck, board, stats);
        UpdateStats(move, is_capture, inCheck, board, stats);
        if (inCheck && new_nodes == 0) {
            ++stats->checkmates;
        } else
            nodes += new_nodes;
        unmakeMove(board);
    }
    return nodes;
}

void PerftStatsRoot(uint8_t depth, board_s *board)
{
    perft_data_s data[MAX_DEPTH];
    memset(data, 0, sizeof(perft_data_s) * MAX_DEPTH);

    perft_stats_s stats[1];
    memset(stats, 0, sizeof(perft_stats_s) * 1);

    uint64_t start = getTime();

    printf("\n");
    printf(" depth                 nodes    elapsed ms\n");

    uint64_t totalNodes = 0;
    uint8_t d;

    bool in_check = isInCheck(board);

    //for (d = 1; d <= depth; d++)
    for (d = depth; d > 0; --d)
    {
        uint64_t sp = getTime();
        uint64_t nodes = PerftStats(d, in_check, board, stats);
        totalNodes += nodes;

        memcpy(data[d].stats, stats, sizeof(perft_stats_s) * 1);
        data[d].nodes = nodes;
        data[d].elapsed = getTime() - sp;

        memset(stats, 0, sizeof(perft_stats_s) * 1);
    }

    for (d = depth; d > 0; --d)
    {
        perft_data_s *curr_data = &data[d];
        perft_data_s *prev_data = &data[d - 1];
        curr_data->stats->captures -= prev_data->stats->captures;
        curr_data->stats->en_passant -= prev_data->stats->en_passant;
        curr_data->stats->castles -= prev_data->stats->castles;
        curr_data->stats->promotions -= prev_data->stats->promotions;
        curr_data->stats->checks -= prev_data->stats->checks;
        curr_data->stats->discovery_checks -= prev_data->stats->discovery_checks;
        curr_data->stats->double_checks -= prev_data->stats->double_checks;
        curr_data->stats->checkmates -= prev_data->stats->checkmates;
    }

    for (d = 1; d <= depth; ++d)
    {
        perft_data_s *curr_data = &data[d];
        printf("%6d  %20s %10" PRIu64 "\n", d, formatNumber(curr_data->nodes), curr_data->elapsed);
        perft_stats_s *st = curr_data->stats;
        printf("    caps: %" PRIu64 "\n", st->captures);
        printf("    enpa: %" PRIu64 "\n", st->en_passant);
        printf("    cast: %" PRIu64 "\n", st->castles);
        printf("    prom: %" PRIu64 "\n", st->promotions);
        printf("    chec: %" PRIu64 "\n", st->checks);
        printf("    dich: %" PRIu64 "\n", st->discovery_checks);
        printf("    doch: %" PRIu64 "\n", st->double_checks);
        printf("    chmt: %" PRIu64 "\n", st->checkmates);
    }

    uint64_t elapsed = getTime() - start;
    uint64_t nps = NPS(elapsed, totalNodes);

    printf("\n");
    printf("depth       : %u\n", depth);
    printf("nodes       : %s\n", formatNumber(totalNodes));
    printf("nps         : %s\n", formatNumber(nps));
    printf("time        : %" PRIu64 "ms\n", elapsed);
}

```

I save the result in an array struct and after that I loop over the array to update the counters to show the correct counters, like this:

```
counter[depth] -= counter[depth - 1]

```

# Answer
> 1 votes
It doesn't look like you're counting mates at the leaves. Your `depth == 1` code is *almost* the same as the rest, except that counting mates is omitted. This would explain why your mate counts lag behind as you described.

My suggestion would be to get rid of the `depth == 1` block entirely (since to make it correct would require it to be exactly the same as the code immediately below it) and instead add a `if(depth <= 0) return 1` at the top of `PerftStats`

---
Tags: programming, statistics, perft
---


title: Games with consecutive en passants

text:
# Question
Title: Games with consecutive en passants
Games with consecutive en passants, that is one side makes two en passats captures in a row, are few and far between to my knowlegde. I only know of one example thanks to Tim Krabbe.

Kudrin-R Douven, 1989

Can anyone find more games that have this unique feature?

# Answer
> 2 votes
I searched through all of the 1 317 676 games in The Week in Chess found two that fit the criteria.

1. H Dang vs D H Nguyen, 2015
2. P Ponkratov vs V Fedoseev, 2016

# Answer
> 1 votes
Here's a game with *three* consecutive en passants. The catch is that it's a proof game composition, rather than an over the board event. But it's spectacular because there is a completely unique sequence of moves ending with Black's 17th move to reach the diagram. This is the only known sound proof game for this task. Even reaching *one* en passant is not trivial in a proof game - a lot harder than forcing castling! There are no famous players here, but the composer is the well-known French ex-fighter pilot Thierry Le Gleuher.

I have not included the game yet because some might enjoy solving it.

```
[Title "Thierry Le Gleuher - R028c Probleemblad 01/1999 - 2. Preis ex aequo "]
[fen "6nr/p3b1p1/1k2bqp1/1p6/8/Kppp4/P4PPP/RNBQ1BNR w - - 0 1"]

```

---
Tags: famous-games, en-passant
---


title: Material score in analysis report

text:
# Question
Title: Material score in analysis report
Is it possible to do an analysis using Scid vs PC or any other major chess program where it shows material score after each move in addition to showing the normal evaluation score? So for an endgame of let's say a king with 2 knights vs king with a bishop the material and evaluation scores would show (6-3 +0.0) on the last move of the game.

# Answer
Check the program pgn-extract (https://www.cs.kent.ac.uk/~djb/pgn-extract). It has what you probably need. Here I copy a fragment of its help:

> Include a position evaluation after each move (--evaluation)
>
> The --evaluation argument causes a comment to be appended to every move, which contains an evaluation of the position immediately following that move. The default evaluation is a simplified version of Shannon's board evaluation. In this case, the evaluation is the difference between the value of White's position and Black's, where the value of a position is a weighted sum of the pieces plus a multiplier (0.1) applied to the number of available moves for that player.
>
> I see this primarily as being a hook for people who wish to embed their own evaluations in the output. See the evaluate function in apply.c if you wish to write your own.
>
> However, an alternative approach to annotating games with engine analysis would be to consider using something like my UCI-analyser that can pass suitably formatted PGN files to a UCI-compatible engine. See, for instance, the section on obtaining annotated output in PGN format.

pgn-extract: A Portable Game Notation (PGN) Manipulator for Chess Games Version 19-04 by David J. Barnes (@kentdjb)
> 1 votes

# Answer
I found the following utility that seems to do the task in a very straightforward way:

http://www.lutanho.net/pgn/pgn2fen.html

So I ask, is it hard to code this? If so, why is it software programs don't offer this feature in their exporting options?
> 0 votes

---
Tags: engines, analysis, scid, material
---


# Question
Title: How to calculate percentage of accuracy of game-play based on the number of mistakes, blunders and inaccuracies?
For some time now, chess.com analysis suggests the accuracy of the gameplay based on the blunders, mistakes and inaccuracies, one committed during his/her gameplay. Now, my question is,

**Whether there is any formula to calculate the accuracy of gameplay based on the inaccuracies, blunders and mistakes during the game? If not, then what are the other factors, that act on the accuracy?**

# Answer
The gameplay accuracy is a scale from 0 to 100 and it is calculated based on the accuracy of each of your moves. Chess.com collects a lot of data from played games that they use to evaluate which moves are more important for the final accuracy.

The final accuracy is a weighted average and that explains when you play a game with two book moves and a blunder why you can get an accuracy of 0.7 and not 66.7.

The average of a single move is determined by how close the evaluation deviates from the top engine suggestion and how far is the evaluation rank placed. If the move played was the 2nd best but was -3 instead of best -1, then that is more accurate than if the same move had 9th rank.

Chess.com has released these two articles that give some insight on the analysis:
How is it measured?
How to use game analysis?

**Note:** Chess.com isn't open source and they haven't shared all the details of the calculation, so more explanation needs more speculation.
> 5 votes

# Answer
You cant. They are just a rough guide about how you did.

The only factor is who won/lost the game.
> -2 votes

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Tags: engines, analysis, online-chess
---


# Question
Title: What is the process for amending the rules of chess?
I read the whole document issued by FIDE containing the Laws of Chess, but nowhere does it say how (or even *if*) the rules of chess can be amended.

Is every change to the rules supposed to yield a new variant? But then, what about minuscule changes like allowing the king to castle out of check, or slight tweaks on how *en passant* works? If, for example, the double-advance rule for pawns had never been invented, would there really be no way of introducing it into chess now? Would we just end up with "standard" chess and "pawns-can-move-two-squares-forward-on-their-first-move" chess?

Plus, a way of changing the wording of the rules ***must*** exist—when the rules where amended to explicitly disallow vertical castling with a pawn that had just been promoted to a rook (which the rules accidentally allowed previously), someone did manually rewrite a portion of the rules in a way that was binding for everyone else.

So what is this way, and who can do so? Is it FIDE? Are there any meetings that take place according to a regular schedule where potential changes can be submitted and discussed? Who can submit these proposals, and once they are approved, are they binding for all national federations?

# Answer
> 15 votes
FIDE has a Rules Commission (https://rcc.fide.com) which reviews the Laws of Chess every four years according to their FAQ. I don't know about the process itself, but if I had to guess I'd say it involves lots of committee meetings and emails. :-) One interesting detail, though, is that they have a form you can fill out with suggested changes to the Laws: https://rcc.fide.com/form-of-loc-change-proposal/

But like the FAQ also says,

> Considerable changes were made in the 15th century. The scope of the queen and bishop in particular were increased then. This made it a much faster game. The Laws are reviewed every four years, but these are either just tidying up, or changes to the Tournament Rules.

So don't expect any changes to things like how the pieces move, other than possibly closing of loopholes like the one about vertical castling which you mentioned (are there any loopholes left? That's a separate question).

# Answer
> 11 votes
According to the FIDE Charter:

> 7.5 FIDE Ethics and Disciplinary Code, Electoral Rules, Financial Rules, **Rules on Laws of Chess** and Zonal Council Rules are approved and modified by the General Assembly, by simple majority, and cannot be superseded nor derogated by rules of an inferior level.

FIDE in general is run by a number of non-elected commissions which have individual responsibility for governing different areas and driving change in those areas. The commission in charge of updating the FIDE Laws of Chess is the Rules Commission.

Usually once every four years the Rules Commission draws up changes to the FIDE Laws of Chess which it recommends and presents them to the General Assembly for consideration. The next set of changes is due in 2021. In the run-up to the 2017 changes there was a call for FIDE members to email the commission with suggestions. I haven't seen that so far this time round but maybe it is still too early. The new commission also looks different under the new head of FIDE, Arkady Dvorkovitch, so no guarantee that it will work the same way.

> once they are approved, are they binding for all national federations?

According to the FIDE Charter:

> 7.10 Each FIDE organ can approve Internal Rules, concerning its functioning, by majority of its components. Internal Rules cannot supersede nor derogate other FIDE rules, in accordance with the hierarchy listed in 7.1.
> 7.11 All FIDE members, organs and officials must observe FIDE rules and regulations.
> 7.12 All FIDE members must include, in their statutes, the obligation for their members to observe FIDE rules and regulations

So, yes, this is quite tightly specified.

---
Tags: rules, fide
---


# Question
Title: How can I deal with frustration in not being able to solve puzzles in time?
I've been doing 1700-2000 puzzles for some days now. My problem is that when I cannot find a solution within 10 minutes, it literally kills me inside. I just get so frustrated and angry. Theh I just see the solution and then try to memorize it. Is there is any solution to this problem, or does it happen with everyone at some point?

# Answer
> 5 votes
It happens every day to a lot of players! Some problems are very hard and can be very frustrating.

My advice would be to try hard during "your 10 minutes", and if the problem is challenging to move on without seeing the solution. Come back to the puzzle after you've had a break and cleared your head. At least, that works great for me!

# Answer
> 5 votes
1700-2000 rated problems are generally going to be 2-3 moves or at the very least forcing combinations. They shouldn't take 10 minutes or anywhere near that. If you're spending that long on them that means you're lacking the pattern recognition of the simpler tactics that are the building blocks.

You need to work on solving simpler 1 and 2 move combinations and develop your pattern recognition. I used to take a simple tactics book and time myself for how long it took to go through the entire book.

Seeing simple tactics quickly is the building blocks for seeing the more advanced combinations.

Frustration is good to an extent because it means you aren't happy with the results you're getting. The solution is to change your approach because the way you're doing things isn't working.

# Answer
> 3 votes
You have to be honest with yourself at first. It is impossible that you gonna solve all the puzzles, you will ALWAYS be facing one or other that you can not solve in time. SO, use this to your advantage! Expect this one. Search for this one. Wait patiently for this one. And when it comes, laugh about it, because you was prepared for it. Also, obviusly, study why you can not solve this one, so MAYBE one day you solve it all.

"Pain is not there to hurt, but to make you aware."

*Probably some Buda*

# Answer
> 2 votes
You deal with frustration in many ways. If the self help books do not cure you then see a shrink.

If you meant to ask how do you learn to solve puzzles faster then it would depend on your ability. Everybody hits their limit at some point. Otherwise you need to study more first then solve puzzles of that type. Just doing random problems will not help you improve much.

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Tags: tactics, psychology, puzzles, time-management
---


title: The Vienna Game: Good, inferior or bad?

text:
# Question
Title: The Vienna Game: Good, inferior or bad?
I have been taking a look at 1.e4 2.e5 2.Nc3, which is known as the Vienna Game. At this point I have become familiarized with a substantial amount of variations and main lines. The principal bifurcation comes on 2...Nf6 or 2...Nc6 by Black, which provides two quite different "systems", since 2...Nf6 allows a strong 3.f4. Apart from this, I have studied quite a number of master games. My overall conclusion is that the Vienna Game is a sound, promising line for the 1.e4 player. It offers positional, strategical struggle in some lines, and sharp aggressive play on others, so players of all styles may find it enjoyable. Of course, Black has the chance to equalize if he knows what he's doing, but in what opening is this not the case?

I then want to ask the opinion of more experienced players than myself: do you consider the Vienna Game to be equally good to other 1.e4 lines, such as the Ruy Lopez or the Scotch? Inferior to them, but still god? Or not even good at all? My question comes from the fact that this opening is hardly ever seen in master play, and it is usually only played on blitz/rapid games as a surprise weapon.

# Answer
The International Master Gary Lane in his book about the Vienna game wrote in 2000 that this opening "has a long history and a bright future". He added

> "in these days of computer databases \[already 20 years ago!\], opening theory has become so intense that some variations have been analyzed to move 30. It is hardly surprising that some 'forgotten' opening variations have been revived by players to looking into unknown territory, and the Vienna is a perfect arena for this."

So, if Vienna suits you, if you like the obtained positions, if you know the main theme (e.g. which pieces to swap, which promising pawn structure to get, ...) go ahead!

Here are some stats about the Vienna game compared to others openings in a Big and a Masters database. In the Big one, the Vienna game is the second choice and compared to 2.Nf3 it offers a higher risk (more losses) but also a premium (more gains). The Vienna is the 3rd choice in the Masters database with also a higher variance.

---

In the Big database

##

In the Masters database
> 10 votes

# Answer
After **1.e4 e5 2.Nc3 Nf6 3.f4**, White has definitely a playable position, but it's not that "strong". Indeed, this is the main line and Black should be about equal with correct play. Other lines will most likely tranpose into other **1.e4 e5** positions (say **2...Nc6 3.Nf3 Nf6**)

So yes, the Vienna opening is indeed a playable one, probably not "the best", but the difference is not big enough to refuse to play it except maybe at the highest levels of play (if you are rated 2500 or below, you can play it with no problems, and indeed it can be a dangerous, surprising weapon)
> 5 votes

# Answer
At top level, the Vienna is certainly inferior. You can try checking the cloud analysis at Lichess. The position after 1.e4 e5 is about +0.3 in favor of White, but the position after 1.e4 e5 2.Nc3 is 0.0. In words, this means the Vienna is not as good as 2.Nf3 at fighting for an opening advantage.

However, if you aren't playing at top level (I doubt you are, simply because almost everyone on the planet isn't), then the Vienna is certainly viable. "Winning" in the opening is mostly a matter of reaching a playable position one is familiar with while the opponent isn't. At club level you can certainly expect opponents to know a *lot* more about 1.e4 e5 2.Nf3 Nc6 than they do about the Vienna. In fact it's entirely possible that your opponent is out of book after 1.e4 e5 2.Nc3 Nf6 3.f4. This move flips Stockfish's eval to negative, but if opponent has never seen this position before, will they even know that 3...d5 is the only move that doesn't lead to an advantage for White? I doubt it. They could very well react with 3...exf4 (after which 4. e5 Qe7 5. Qe2 forces Black to play 5...Ng8) or something even worse like 3...Nc6 (after which 4.fxe5 Nxe5 5. d4 pushes Black off the board). Wikipedia says as much:

> However, lines other than 3...d5 give White at least an edge, making this a good choice for aggressive play at lower levels, where opponents are unlikely to know that 3...d5 is best.

Of course if you keep playing against the same people they will quickly learn the nuances of the opening, and an opening edge becomes harder and harder to find. But until they develop as good a grasp of the Vienna as you, you will likely continue to score easy wins.

Viewed the above way, the Vienna is a great opening because it's easy to get. If you play 1.e4 there's a very good chance the opponent responds with 1...e5. This is in contrast to, say, the Scandinavian where you might prepare a line but never get the chance to use it.

**Summary:**

1. Against an opponent as booked up as you, don't play the Vienna.
2. Against everyone else, feel free!
> 2 votes

# Answer
The Vienna is one of the better openings below international level. Objectively it's probably equal but that's true of nearly every opening. There's only a few openings that can even try to claim a small advantage nowadays (Ruy, Queen's gambit)

What I like about the Vienna:

1. it cuts off a lot of black responses like the Petrov, Philidor, Latvian etc.
2. It's very flexible. There are a lot of ways to play the Vienna. You can play the standard Frankenstein–Dracula Variation or you can transpose to a four knights or you can play something like the Bishop's opening or you can look to transpose into a king's gambit or you can play a very system-like approach with Bc4, d3, f4, Nf3 etc. The Vienna gambit with an early f4 is also surprisingly sound.
3. It's somewhat unusual meaning most black players won't as prepared as they should be.
4. It narrows your opening rep. Aside from what I said in #1 you can play 2. Nc3 as an answer to 1...Nf6. Black's best reply is 2...e5 transposing to back to the vienna game main lines. You can also fall back on the Bc4, d3, f4, Nf3 formation if black throws something at you you don't know how to play. With black you can play the dutch and reach the same positions if white doesn't prevent e5.
> 1 votes

# Answer
It's great until you reach 2000. After that don't use it as a main repertoire. The main repertoire should be the main lines. Then along the way you can get creative.

Knowing why the main lines are in fact the best will greatly improve your play **after 2000**

Hope this short but sweet answer helps!
> 0 votes

---
Tags: opening, 1.e4, vienna-game
---


# Question
Title: Where can I find this game with a sacrifice followed by a long series of checks leading to a discovered mate?
I am looking for a chess game and frankly, I really know very little about it. I remember seeing it somewhere on the Internet.

The game goes something like this. A player (either White or Black) sacrifices their most important piece, probably the queen. This starts a continuous checking sequence. Check is continuously repeated 10-11 times with the opponent's king always having to play a forced move. The opponent's king is forced to move from their rank to the last one. Then the attacking player moves their king to expose the attack of a rook already there, checkmating the opponent.

I know this is near to no information. I have searched the Internet and this site to find this game. But, as I do not have any concrete information, I am not able to find it.

Can you please help me?

# Answer
I believe that the game you speak of is the extremely famous Lasker-Thomas match in which Lasker forces Black to accept his queen "sacrifice" on move 11. It is followed by a king hunt in which Black's king is forced to the last rank by White, who then finishes the game with the king giving a discovered check from the unmoved a8 rook. The game is notable because White could have chosen the exemplary move 18. 0-0-0#, which is exemplary because castling while also delivering checkmate has been a rare achievement in chess history, but Lasker instead chose the more mundane, in my opinion at the least, 18. Kd2#.

The checking sequence isn't quite 10-11 moves long, but otherwise it fits the bill perfectly, especially with the particular mating move that you described.

```
[Title "Edward Lasker-George Alan Thomas, London England, 10/29/1912"]
[FEN ""]
[startply "20"]

1. d4 e6 2. Nf3 f5 3. Nc3 Nf6 4. Bg5 Be7 5. Bxf6 Bxf6 6. e4 fxe4 7. Nxe4 b6 8. Ne5 O-O 9. Bd3 Bb7 10. Qh5 Qe7 11. Qxh7+ Kxh7 12. Nxf6+ Kh6 13. Neg4+ Kg5 14. h4+ Kf4 15. g3+ Kf3 16. Be2+ Kg2 17. Rh2+ Kg1 18. Kd2#

```
> 51 votes

---
Tags: endgame, tactics, sacrifice, famous-games, identify-this
---


title: What is this position called?

text:
# Question
Title: What is this position called?
I'm working on a problem for this cyber security camp, and we're doing a CTF right now. I have one problem left, and I'm almost certain in relates to chess, so I've come here for advice!

> Having determined the name of the bank, the FBI’s last step is to find Hax0r’s personal account. Strangely, when confronted with this question during interrogation, Hax0r agreed to tell us - but only if we played him in a game of chess. The FBI agreed, but when we got to the position on the board as shown below, Hax0r exclaimed, “You got it!” Can you figure it out what Hax0r meant? What is Hax0r’s account name in the offshore bank?

# Answer
The position doesn't make any sense.

But the pieces spell out several letters. Clockwise from the top left: o,t,o,r

Maybe that's helpful?
> 2 votes

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Tags: puzzles
---


# Question
Title: Do grandmasters practice blindfold chess or does it come naturally with practice?
Since grandmasters are good at calculation, do they practice blindfold for improving calculations, or does it come naturally over time by solving a lot of complex calculations?

# Answer
> 3 votes
My answer is, it comes naturally.

The more often you see the chessboard, the more it will internalize at some point. Even though I am only an IM, the ability to play blindfold came naturally to me at some point.

Often players who participate in a lot of tournaments write down the moves on a scoresheet at mentioned earlier. But also, in analysis with others we are constantly mentioning moves and internalizing the coordinates of the chessboard. It is hard to say though at which point it happens, but it does happen.

I am not sure how to explicitly practice this skill though. Reading chess games without a board will definitely increase the ability.

One other thing I have noticed is that an absolute topGM like Gelfand does not even look at the board anymore. He is often sitting with his head down, and flipping a pawn while contemplating. This has led me to believe that the actual position is can be unwanted background noise for some!

# Answer
> 13 votes
Your question is quite interesting. If you are new to blindfold, I think this thread will help you: Can playing blindfold chess be learned or is it a natural skill?

Now, back to your query. I have discussed this topic with a GM, who is one year senior at my college. According to him, playing *blindfold* is "NOT impossible", but it's fairly difficult. As they participate in lots of classical tournaments where they have to write the scoresheet by hand, it is easy for them to quickly visualize the board. Also, their training process helps them to calculate from certain positions without playing the moves. But, on the other hand, it is fairly difficult to keep up every possible move, visualize every possible position and that needs intense focus and concentration. But, since they are calculating and visualizing chess more often than normal people, it is comparatively easy for them to play blindfold chess after practising for some time.

In a nutshell: it doesn't come naturally over time without practice, even if you are a GM.

# Answer
> 3 votes
I discovered I could play blindfold by accident. I was playing a game online and the pieces didn't load onto the screen but I could still play. I (surprisingly) won the game fairly easily. I've played quite a few blindfold games since then. I still make some dumb mistakes but I can follow the game for the most part. I'm probably 1500-1600 blindfolded.

The longer the lines you can visualize and the more opening theory you know the easier it is. I like to sit quietly with my eyes closed and cut off all external stimuli as much as possible. To me, maintaining concentration is the hardest part.

If you pay long enough and get good enough you'll probably reach the point where you can play blindfold without much effort. On the other hand, you can practice it and get better too though just like anything else, although you'll always have a ceiling of where your normal chess ability is.

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


title: What is the idea behind this move?

text:
# Question
Title: What is the idea behind this move?
I was watching Nepomniachtchi - Liren match on Chess24 Legends Day 2. After having a pretty significant advantage \[+7.1 (Stockfish 11)\], White \[Nepo\] has played **g4**, and according to the engine, the game could be drawn by something sort of perpetual checks or three-fold repetition,

Since after g5+, Kh5; Black can make his king pretty safe in the pawn structure and also its active queen bishop combo can neutralize white's attack by giving perpetual checks; so my question is:

**What is the idea behind the move g4 in this situation?**

# Answer
> 4 votes
First of all, I do not think Black's king would be safe at all on h5. After Kh5 simply Rd4 would threaten Bf3#. Many other concrete threats also come to mind with the king on h5, but the idea is the same: the king is one check away from checkmate, since no squares are available for him. Of course all of this is ignoring the fact that Black can force a draw.

I believe g4 is simply an overlook (yes, they happen in the elite too). Nepo was probably too enthusiastic about the threat of g5+ with all the subsequent mate threats after Kh5 that he overlooked the forced draw. So to answer your question: I think the idea behind g4 is simply to create a mating net against the enemy king. A strange overlook by such a strong player anyway.

---
Tags: analysis, theory, tournament, online-chess, grandmaster
---


# Question
Title: How to play this endgame without consulting the tablebases
Recently I got this position in a game I played as Black with White to move.

```
 [FEN "8/8/8/R6p/4KP1P/6P1/pr6/1k6 w - - 0 1"]

```

Here, White captured with the move 1.Rxa2. It turns out that 1... Kxa2 is winning while 1... Rxa2 loses. Is there any way to see that Kxa2 must be played instead of Rxa2 without turning to the endgame tablebases? How do you judge such endgames?

# Answer
> 7 votes
In positions where the side with the Rook is trying to hold back the passed pawns it is often critical how quickly the King can scramble back to base, because the Rook will usually be easy. If for example the King must reach g8, then ..Kxa2 leaves the King with one rank less to cross and therefore (other things being equal) will save a tempo. Therefore my instinct would tend toward ..Kxa2 rather than ..Rxa2, even before attempting any analysis. The question whether other things truly are equal is the reason why endings in general need a lot of calculation. In this case they probably are.

However, why did White take the pawn before it promoted? 1.f5 waiting for 1..a1=Q 2. Rxa1 Kxa1. White would then be two tempi up compared to the game. He made Black spend a move on promoting, and also ensured that the Black King would have to cross all eight ranks.

---
Tags: analysis, endgame
---


# Question
Title: Does some GM or notable coach consistently employ "hand and brain" as a teaching tool?
I've seen some streamers do what they call "hand and brain", meaning that one person plays while the other chooses the kind of piece that they must move. All cases I've seen were intended for having fun. But it got me thinking about how effective would this be as a teaching tool.

My question, at heart, is: "Is playing hand and brain with a student an effective teaching tool?" Since this is probably too opinion-based, I only ask if there are cases of GM's/notable coaches that employ it as a teaching tool consistently. If there are references attesting to it being an effective teaching tool, those are of course appreciated.

# Answer
> 2 votes
As an IM and experienced chess coach I can say I only use it in play and for fun. Serious training should be learning concepts and solving a lot of puzzles.

The only time I do use it is when one person is clearly stronger than the other and the weaker side needs some help. Especially absolute beginners who completely mess up all my plans are my favorite partners!

In theory of course you could use it once in a while as a training exercise, the players can learn from the plans of the others, but other than that I do not see any big use. Sorry, I do think it's fun, but fun and use are different.

# Answer
> 1 votes
With the coach as "brain", it probably doesn't hurt, but I don't see it as an effective tool, since it'd be making most of the decision for the student (the exact opposite of what training should be like).

With the student as "brain", then it's the equivalent of playing a game of chess

# Answer
> -2 votes
Not at all effective.

In fact it would be counterproductive as a teaching tool intended to help a player improve.

---
Tags: learning, grandmaster, teaching
---


# Question
Title: Can I download early versions of Leela chess zero?
I want to play weaker versions of Leela. It would be good to play some really early versions of the net. Is there a repository available where I can download them?

# Answer
> 4 votes
For early versions, the lczero project's download page refers you to the lc0 releases available on GitHub. For versions from 2018, you can go the lczero repository on GitHub.

Note that while the downloads from from the former repository (lc0) provide both Windows builds and source code, the older releases from 2018 (lczero) give you only source code that you need to compile by yourself.

---
Tags: training, leela, human-versus-machine, chess-ai
---


# Question
Title: Why is the French defence not played at the highest level?
I am a French defence player and I enjoy playing almost all the lines (Tarrasch, Winawer, advance variation, ...) because I think the play that follows the opening suits my style and I feel very comfortable. I am a club player (~1800).

I have realized lately that at the very top level the French is not played. Most of the games that start with **1. e4** end up being Sicilian defences, Berlin Walls (or some other lines of the Ruy Lopez) or even some Caro-Kann (I recall at least a game or two of Giri playing this).

If we don't consider just the very top level (which I consider to be the top 20 players in the world more or less) we can find some 2700 rated players who have played the French (I recall some game from Vallejo now).

So I wonder why is the French not played more often. **Which is the line for white that gives the greatest advantage?** **Could anyone point me to a reference explaining how to "refute" the French with white?**

# Answer
> Why is the French defence not played at the highest level?

If you consider any statistically small (~20) sample of chess players, regardless of standard, then you will get clustering of openings chosen. This has very little to do with soundness or otherwise and much to do with fashion and temperament. Just look at someone like Nakamura.

> So I wonder why is the French not played more often.

Normally when black chooses to play the French he wants an unbalanced position with double edged play. However white does not have to agree with this. If white just wants a draw then he can always play the exchange variation when the whole nature of the position changes and a draw becomes much more likely. This is usually not what black wants.

> Which is the line for white that gives the greatest advantage?

It is the line where black makes the worst mistake ;-). Seriously, no line gives white a big advantage with best play on both sides.

The Tarrasch is more popular at higher levels but this has nothing to do with size of advantage. I think it has much more to do with flexibility. Other lines commit white earlier to a particular route while the Tarrasch generally lets white keep more options open for longer.

Interestingly the Advance variation is more popular at lower levels because it reduces the flexibility ;-). After this black can no longer play the Rubinstein with ed4 and nor can he put a knight on f6. Of course he can put a pawn on f6 attacking the front of the pawn chain and perhaps this is part of the reason it is less popular at higher levels.

> Could anyone point me to a reference explaining how to "refute" the French with white?

No, they won't be able to because there is no way to refute the French with white. There can be some scary lines for black, for instance in the Winawer where white plays Qg4, but if black knows the theory he should be fine (unless white has a novelty!).

Now, if you were asking about the Benoni ...
> 25 votes

# Answer
Peter Svidler answered this in a recent video for Chess24:

> **Why do the majority of GMs and almost all super-GMs play 1…e5 or 1…c5 in answer to 1.e4 rather than the French Defence (1…e6)?**
>
> Peter: I think the answer is twofold. Firstly, both the Spanish and the Sicilian offer you a much broader scope to choose from. If you play 1…e5 you’re not really limited to one structure, let alone one line. That’s not necessarily to say the French is one structure and one line, but it does limit Black’s opportunities more than the Spanish or the Sicilian. But I think the bigger issue with the French is, at least for me, that it was always a very, very difficult opening to understand. I didn’t do that badly in terms of practical results, but actually understanding what’s going on in the opening is another matter – even from the white side, and it’s generally accepted that the white side is the more comfortable side of the French Defence.
>
> That brings me to my second point. This was mainly to do with the fact that I played French games almost exclusively with Alexander Morozevich, who put a tremendous amount of work and imagination into building his French repertoire. If you do that it becomes a very attractive option against 1.e4, because people don’t encounter it that often these days. People are no longer very convinced with their choices and I think it’s very playable and also a very sharp opening that you could argue definitely gives you more counterchances than the Spanish. If the white player would prefer a quiet life he will find it harder to find a quiet life in the French than in the Spanish.
> 44 votes

# Answer
I'm a French Defense player. As Peter Svidler opined in his interview on Chess24, "If the white player would prefer a quiet life he will find it harder to find a quiet life in the French than in the Spanish \[Ruy Lopez\]".

The main reason it *isn't* played is that it is harder for Black to play the French Defense than it is for White to play against it. He accepts the following limitations:

1. He is facing a White pawn at e5 for much of the game in many of the variations
2. As a result, his king's knight rarely gets to sit comfortably on f6
3. As a result, White's queen often goes raiding on the kingside
4. As a result, Black often can't castle safely on the kingside.

These are not problems that most players are comfortable having.

But I play it because:

* It's relatively easy to get the game into areas where I'm better prepared (and in more familiary territory) than White, which is unnerving to a lot of players of White
* It's a fighting defence, with a few traps, clever stratagems, and ways to knock White into burning a lot of time on his clock
* It shows you have nerve, and and that you have probably put a fair amount of effort into learning how to play a defence that can be tricky to handle. This can be intimidating by itself.

Obviously, at the GM and Super-GM levels, the players stay pretty booked-up, and you have to be really adventurous to suprise them (think Sveshnikov/Pelikan Sicilian, Scotch Game, King's Gambit, and so on, which were considered either unplayable or too quiet to be useful when they resurfaced in the latter half of the last century, typically with great success). Many of these players are now starting to try unorthodox ideas in the older established openings, like the Italian Game (Giuoco Piano). The French may get another day in the sun.

In the meantime, it *is* getting played by the likes of Carlsen, Caruana, Nakamura, Anand, Radjabov, Morozevich, Ivanchuk, So, Giri, Karpov, Grischuk, Harikrishna, Gelfand, Leko, Mamedyarov, Topalov, Wang Hao, Ponomariov and others.

So, while it's not getting played as much as the Spanish and Sicilian by the highest-level players, they certainly are playing it from time to time, even in blitz!
> 13 votes

# Answer
No source, and I understand you're not asking about this, but I'm writing this anyway because I suspect you'll be interested.

I'm told at the highest level (correspondence chess), 1. e4 e6 is *at best* a draw for Black. In other words, if you play the French defense as Black, you are playing for a draw - actually even worse than that, since you'll be suffering for a draw as opposed to making a relatively easy draw with a line such as the Berlin, or possibly even fighting for an advantage with the Sicilian. The correspondence chess players I talked to didn't go into details why the French is so bad, but I'm guessing it's because Black suffers from a chronic lack of space on the kingside, which is very dangerous against strong opposition.

Ironically, 1...e6 is one of the most common replies that Stockfish will play if left to its own devices. As a result, I had one correspondence chess player tell me that if opponent plays 1. e4, the best thing you can do to help your engine is to not play 1...e6.
> 7 votes

# Answer
The French Defense requires a lot of sharp, tactical play. It is "like" the Sicilian insofar as it tries to avoid e5 as a response to e4, and take away the initiative from White. But although "tactical," the Sicilian offers more of a positional game than the French. (I play both, but prefer the Sicilian.)

The French Defense was quite popular in the middle of the 20th century with tactical players such as Alexander Alekhine, Mikhail Botvinnik, and Vasily Smyslov. And before them "lesser" lights such as Rudolph Spielmann, and Mikhail Chigorin.

But today's grandmasters are more positional players. On the other hand, with "top 20," you're dealing with a small sample size, so in another half century, you might see the French Defense popular with the then-prevailing group.
> 5 votes

# Answer
The French is played at the highest levels today. For example, the number # ranked player in the world Caruana uses it. There is no refutation of the French. It's a sound opening. However, it may not be well suited for certain situations. For example, the exchange variation is considered vary drawish if White wants a draw. It is true that the current top twenty players seem obsessed with the Najdorf and Ruy Lopez (Berlin Defense) lines as Black because currently it seems that Black can equalize with these lines.
> 5 votes

---
Tags: opening, french-defense, refuted
---


# Question
Title: What does this paragraph about Stockfish's regression tests mean?
Source

Point 5:

> Elo estimates of single patches (SPRT runs) typically come with large error bars. Take this into account when adding Elo estimates. **Furthermore, Elo estimates of passing patches are biased. The SPRT Elo estimates are only unbiased if one takes all patches into account, both passed and non-passed ones.** As a result, the Elo gain measured by a regression test will typically be less than the sum of the estimated Elo gains of the individual patches since the previous regression test.

I don't understand the highlighted sentences. Can someone explain?

# Answer
What this means is that if you assume every test has some noise, if you only look at the tests that turned out well, some of the reason they turned out well was likely that noise was in their favor. As such, you expect regression to the mean if you were to re-test only the passing patches. They would appear less good, because "passing test" is a biased sample.
> 7 votes

---
Tags: stockfish
---


title: Mac - Chess App

text:
# Question
Title: Mac - Chess App
I was trying to play chess on the included chess app on mac, and after the computer's turn, it will not allow me to make any move at all, and I am 100% sure I am not in check as the game just started, still I cannot move a single piece. It does this everytime, has anyone ever experienced it? or knows how to fix it? Here is a screen shot of the app, I am whites and it will not let me move anything.

# Answer
I think that when you started a new game you accidentally choose the Variant "Suicide" or "Losers". (It might be preselected now that you have selected it once.)

### Why would this explain the situation?

In these Variations of chess (you might know them as *antichess*, *the losing game*, *giveaway chess*, *suicide chess*, *killer chess*, *must-kill*, *take-all chess*, *capture chess* or *losums* (according to wikipedia)) you win by having all your pieces captured. The trick is that you *have* to take every piece that you can take and may not make other moves as long as you can capture anything.

In this position black has offered you a pawn on b5 and you will have to take it with your bishop. All other moves are illegal.

### Why I think this is what happened

My guess is based on the position: The computer wouldn't normally just throw away so many pieces (including it's queen). It's pretty hard to come up with a way the game might have gone to end up in this position if the black wasn't pruning it's pieces on purpose.

Also when you selected a variation once, then it will be preselected for the next games until you change it.

### What to do about it?

(If you still have the game open, try capturing the pawn with your bishop. If this is possible then you will have confirmed that this was the problem.)

When starting a new game, select the variant "Regular". You will be able to make normal moves now. (You might notice that the computer is much stronger now and not throwing away it's pieces so easily. Consider adjusting how much the computer thinks ahead in the "new game" menue)
> 4 votes

---
Tags: engines, software, computer-chess, macos
---


# Question
Title: Can't a pawn capture onto the last rank to promote?
I do not play chess much. Recently a friend reached out to play some online games. We ran into an odd situation that I cannot find a rule on.

His White pawn was at **g2** and my Rook was still at **h1**. He planned to take the rook with his pawn to promote it, but the game would not allow him to make the move and we couldn't figure out why.

Is there something illegal about that move? There were no underlying issues with the pawn movement that would leave the king in check or something similar.

Addendum-Per the answer below, I asked him about popups getting blocked. He said he had no problem getting the promotion going forward, but was being blocked from taking the rook.

# Answer
> 8 votes
Black plays from 7th and 8th rank, his king starting from e8, so the white pawn is on b7.

There is no (FIDE) rule that forbids a combination of taking and promotion. b7xa8Q (or whatever) is a legal move.

When playing online at some minor platform, you will often find that the rules of chess are badly implemented. I know of no single platform that plays strictly FIDE rules. So you might find some surprises in future games.

# Answer
> 7 votes
Since the board is mirrored, the pawn is on b7 and the rook on a8. But b7xa8 promoting to a piece is a valid move.

I'm not sure which program/website this is, but it could be that a popup is asking to which piece White wants to promote, and something/your browser is blocking this popup, and your friend cannot complete the move.

# Answer
> 3 votes
The move is legal.

If it were blacks move the computer would block it. If White were in check the computer would too.

LIke @Glorfindel said the popup probably asked for which piece so blocking it stopped the move. But in that case you should still not have been able to push straight instead of capturing.

Do tell us what program/website that was! I do not recognize the board colors but I do not visit all the sites.

---
Tags: rules, pawn-promotion
---


title: Suggestions about books to read

text:
# Question
Title: Suggestions about books to read
I am a beginner player and I am studying the game on some classical books: I began with "A primer of chess" by Capablanca. I would like to continue with these 3 books:

* "Chess Fundamentals" (Capablanca)
* "My System" (Nimzowitsch)
* "Hypermodern chess" (Alekhine)

In which order would you suggest to study these books? Could you also suggest to me something else to study?

# Answer
> 4 votes
Capa's books are very good for your level especially the one you mentioned.

My System is probably too advanced for where you're at. It's a great book but probably better for someone around 1800. Beginners should focus on not making huge tactical mistakes. Positional play like My System teaches you how to plan what to do when you can play a game without making huge mistakes.

I don't know the other one but judging by the title I would say it's way too advanced. You won't be able to understand hypermodern chess until you have a crystal clear understanding of classical centers. Few players below 1800 have any clue what they're doing in the center.

As far what I would recommend-

I really like the book Learn Chess: A Complete Course by C. H. O'D. Alexander. I admit the book can be a little hard to read but it covers every aspect of the game and includes hundreds of tactical puzzles. The chapters on attacking are the best I've seen outside of Vukovic and are targeted towards beginner players.

Silman's Complete Endgame Course: Yes, it's an endgame book but you will learn exactly what you need to know for the level you're at. Endgames are also good for beginners because you break the game down into smaller parts and learn to use the pieces individually.

How to Play Good Opening Moves by Mednis- The book is small but i promise you you can reach 2000 without knowing anything more about the opening than what's in that book. Center, development, king safety. That's all you need to know.

Any tactics book. If you do tactics problems you will get better. Probably the book that will give you the most "bang for your buck" is How to Beat Your Dad at Chess. The tactics are common and the section on facing a strong opponent is good advice.

I'll add one more and that's Rapid Chess Improvement by de la Maza. You can buy the book if you want but the book was based on a couple of articles written by de la maza which are still freely available on the internet (search 400 points in 400 days .pdf etc) Most of the rest of the actual book is testimonials and maybe a little elaboration in some areas. Basically, de la Maza argues that you need to study tactics and develop an effective thinking process to improve from beginner to intermediate. You won't find a strong player anywhere who disagrees with that even if they don't like de la Maza.

# Answer
> 2 votes
There are so many definitions of “beginner” :-) So i can only try some general advices.

Beginners should start with tactics and easy endgames. In Europe, the Stappen method is quite popular and has a lot of materials for beginners and intermediates, but any book with explanation of tactical motives and a LOT of examples will serve. An app with chess puzzles is also a good idea. For endgames, i heard a lot of recommendations of Silman’s Complete Endgame Course. If you can read german, Bernd Rosen “Fit am Endspiel” is a very good start. Some beginners regard the endgame as dull, but it is where you learn about the very nature of your pieces. Serious work at those points will bring you to 1400–1600.

In strategy, “Mein System” is the basis of positional thinking. I also recommend Jeremy Silman “How to reassess your chess“.

The classic books have a lot of value. But you should be aware that chess has evolved since. Some opening systems that have been favorits for Alekhine or Capablanca are considered faulty today. Get the ideas of the game, enjoy their beauty, but always remember: they might be wrong.

With understanding strategy, you might reach 2000.

To improve further, you will have to deal with openings. It really is not necessary to do it earlier. Don’t bother with books. Look at some good videos. I learned a lot at chess24, and there will be others.

---
Tags: books
---


# Question
Title: Why is g5 much better than gxh5 in this position of Anand?
To me, Anand's `13. g5` instead of `13. gxh5` was very surprising.

```
[Title "Vishwanathan Anand vs Nafiz Ediz İlhan, chess24.com"]

[FEN ""]

1. Nf3 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. d4 O-O 6. h3 e5 7. d5 a5 8. g4 Nfd7 9. Be3 Na6 10. Rg1 Ndc5 11. h4 Kh8 12. h5 gxh5 13. g5 Bg4 14. Rxg4 hxg4 15. Nh4 Qd7 16. Be2 g3 17. Bg4 Qe7 18. Bf5 gxf2+ 19. Kxf2 f6 20. Qh5 Bh6 21. Qxh6 Nd3+ 22. Ke2 fxg5 23. Ng6+ 1-0

```

My reasons are:

1. With rook on `g1`, `13. gxh5` gives it a direct open file against the king.
2. `13. g5` allowed `13... Bg4`, necessitating `14. Rxg4`, an exchange sacrifice for the attack to continue.
3. The fundamental idea of any pawn storm, such as that attempted by Anand, is to exchange pawns in front of the king.

It is clear that Anand considers gxh5, but finds it so bad that he says "*I might have been a bit careless here*"!

This completely took me by surprise.

**Why is `13. gxh5` so bad? And `13. g5` much better?**

# Answer
> 1. With rook on g1, 13. gxh5 gives it a direct open file against the king.

Wrong! The black king is not on the g file. It is on the h file and the rook on f8 is ready, if required, to come to g8 and fight for the open file.

> 2. 13. g5 allowed 13... Bg4, necessitating 14. Rxg4, an exchange sacrifice for the attack to continue.

Again, wrong. 13... Bg5 14 Rxg4 hxg4 really does open the file the black king is on, the h file. "allowed" is wrong and so is "necessitating". This sequence accelerates the attack. Without using an engine, 13... f5 looks to be better for black than Bg5, or at least less bad.

> 3. The fundamental idea of any pawn storm, such as that attempted by Anand, is to exchange pawns in front of the king.

Which is what happened in the game (white got rid of his h pawn, opening up the h file against the black king, and got rid of the black g pawn which was defending h5) with the bonus that white's g pawn was retained as a threat.

> Why is 13. gxh5 so bad?

It blocks the h file (the file the black king is on) with a white pawn which white can't remove.
> 5 votes

---
Tags: attack, anand, king-safety
---


# Question
Title: Why is it seemingly impossible to follow high level chess games?
According to this, AlphaZero was a really good chess engine that learned through playing against itself, and it then it never lost against any other chess programs. I think it probably also said it sometimes beat them. I was curious to see how a game between AlphaZero and Stockfish, so went so I started watching a video and then I couldn't at all see for myself why the moves were good, so I lost interest and stopped watching the video part way through. Why is it seemingly impossible to follow high level chess games?

# Answer
Compare this to professional team sports (soccer, American football, hockey, basketball). In general, the offense is trying to score and the defense is trying to prevent scoring. The objectives of the game are clear. When the game is over, everyone knows who won. However, there are lots of subtleties. The precise spacing and movement and coordination of the offensive players. How the defenders position themselves relative to their mark. Casual fans don’t know 100% what the optimal thing for all the players to be doing on both sides at all moments. Very few people do. The best people at doing this are professional coaches, who make millions because they are so much better at using this knowledge than others.

The stronger your knowledge of the game, the better you understand each micro-decision in sports. The same applies to chess: if you play casually, it is harder to understand each and every move an engine makes. Some moves though will still be pretty obvious, even to weaker players, but many are subtle and harder to understand. The higher your knowledge, the more you understand why they choose the moves that they do.
> 4 votes

# Answer
I believe the following is a simplification of an improvisation of the full accurate answer that is too hard to figure out. Chess is a very complex game. Even without the 50 move rule or 3 fold repetition rule, figuring out for any possible state that can occur in a legal game which moves force a draw and which ones force a win requires a very large number of computations. How much of a short cut there is, I don't know. You can force a win if there is some odd number such that you can force a win in that number of half moves. Your opponent can force a draw in 2 half moves if they have a move that prevents you from having a forced win in 1 half move. You have a forced win in 3 half moves if you have a move that prevents them from having a forced draw in 2 half moves. They can force a draw in 4 half moves if they have a move that prevents you from having a forced win in 3 half moves. Directly from the definition of having a forced win in 21 half moves or forced draw in 20 half moves, using brute force, you would need an insanely large number of computations to figure out how to force a win in 21 moves if you can or force a draw in 20 moves if you can if you can't force a win in 19 half moves.

Real people in rated slow FIDE tournaments have a limited amount of computation power and play against people with a similar amount of computation power. They're trying to make it as hard as possible for their opponent given their similar amount of computation power. A move that is a bad move for your level in the tournament you're playing could be a really good move if you suddenly magically gained a lot more computing power because then for every move you could make, you could do just as good a job of checking in advance what will happen after it as your opponent could do after you've already made the half move. In reality, you don't have the ability to do that with an opponent the same level as yourself. I think we both keep having half moves we can judge probably won't lead to a quick loss because we are thinking with our limited computing power the odds are low that the move we make will give them a quick forced win that their level can figure out because why would you expect it to lead to a quick loss? However, only once they actually make they make their move, you can then see for yourself that you still don't have a quick loss with your levels although that was only guess work on your part earlier since you couldn't see that far ahead in the game by that time.

When you see a chess game like the AlphaZero vs Stockfish match I talked about in the body of the question, both programs are thinking really far ahead. You don't have enough computing power to see why they're good moves for their level. All you can to is study their inner workings and assuming the observed result of them is mathematically correct, conclude that the half move it made was a good move for its level.
> 1 votes

---
Tags: learning, master-games, alphazero
---


# Question
Title: Why are my tactics ratings on chesstempo and puzzle rush different?
I just started chess.com puzzle rush today for the first time. My chesstempo blitz puzzle rating is 1567, but I can only get to 16-17 on puzzle rush, which is about 1000-1100. My mouse is bit slow, but still, shouldn't I be reaching 25-27? What am I doing wrong?

# Answer
After reading the comments, now I understand the question. The answer is simple: **time**. On ChessTempo you don't have a time limit, while on Puzzle Rush you have to answer within a few seconds if you want to make it to problem #25 or above. You also get a 1500 ChessTempo rating by getting right a certain amount of problems at that level (if you get them every single time your rating will go above that), but on Puzzle Rush you can only fail twice, so you'll need an effectiveness bigger than 90%... while answering within a few seconds!!!

There's also the difference in rating systems (each site could assign different ratings to problems of similar difficulty), so, as I wrote in the comments, if two numbers mean different things, you shouldn't expect them to match, despite looking related in appearence
> 4 votes

---
Tags: tactics
---


# Question
Title: What is a good free interface to create and store positions?
I'm getting back into chess, and I'd like a way to create and store multiple chess positions to review. Specifically, I want to review and practice mating nets. There are a ton of chess tactics sites that offer tactics training, but I want to be able to create and review specific types of positions. Does anyone have suggestions?

# Answer
> 1 votes
If you have a PGN file of those position you could use my site for that. There are already a couple of people using the site not to study openings but have uploaded PGNs of endgame positions to train.

If your PGN software specifies a starting position not inside of a "FEN" header let me know: https://github.com/ArneVogel/listudy/issues/2

---
Tags: tactics, checkmate
---


title: Who was the first modern grandmaster?

text:
# Question
Title: Who was the first modern grandmaster?
According to Wikipedia, the modern system for awarding FIDE titles evolved from the "Dorazil" proposals, presented to the 1970 Siegen Chess Olympiad FIDE Congress. On the same Wikipedia page it is written that, to qualify for the grandmaster title, a player needed to achieve three GM norms within a rolling period of three years. Exceptionally, if a player's contributory games total thirty or more, then the title could be awarded on the basis of two such norms. (I guess the 2500 rating requirement was added later.)

I would be curious to know who was the first player to obtain the GM title under this new system. A bunch of players obtained the GM title at the beginning of the seventies (see here).

# Answer
The Wikipedia reference gives 3 names for 1970 - Bukhuti Gurgenidze, Walter Browne and Anatoly Karpov.

Wikipedia's Bukhuti Gurgenidze article lists only the Tbilisi tournament taking place in December 1969.

Walter Browne's Wikipedia article says this:

> His zonal result earned him an invitation to an international grandmaster tournament in San Juan, Puerto Rico. There, he gained the Grandmaster title by tying for 2nd–4th places, with Bruno Parma and Arthur Bisguier, behind reigning world champion Boris Spassky

So, San Juan was his final norm.

In neither case do we know from these sources when the actual title was awarded because titles are not awarded until federations apply for them on behalf of the players and applications cannot be considered and approved until there is a FIDE congress or board meeting.

For Anatoly Karpov we do have a specific date in Bill Wall's blog:

> In June, 1970 Anatoly Karpov tied for 4th place at an international tournament in Caracas, Venezuela, gaining a Grandmaster norm. He was awarded the Grandmaster title at the 1970 FIDE Congress in Siegen in September, 1970 at the age of 19. He was the world's youngest Grandmaster.

Given that Browne and Gurgenidze's tournaments took place in 1969 it is unlikely that their title applications came in after Karpov's. The Siegen congress was the congress at which the changes were made and so it could be that all three were agreed at the same time. In any case, Karpov is certainly one of the first.
> 2 votes

---
Tags: history, fide, grandmaster, famous-players
---


# Question
Title: Looking for analysis or games of top players in less known, perhaps a bit dubious but aggressive lines in the Ruy Lopez from Black's point of view
When my opponent plays 1. e4 I reply with 1... e5. When the game shifts to Ruy Lopez after 2. Nf3 and 3. Bb5 I respond 3... f5. Although this opening is to my taste, I am not reluctant to learn more about chess and Ruy Lopez. I've heard an anecdote that a deceased GM once said that playing the Ruy Lopez can improve your chess overall. With that in mind I am into playing the Ruy Lopez, but preferably lines that

1. don't require white to cooperate that much
2. are sharp, possibly dubious
3. deviate from mainlines such as Breyer, Berlin, d3, Marshall, Chigorin, Zaitsev etc.

# Answer
There are a couple of games between AlphaZero and Stockfish. The authors of the book Game Changer about AlphaZero, GM Matthew Sadler and WIM Natasha Regan, analyse the opening phase of these two games in this YouTube video.

Here are the opening moves from the two games, first with AlphaZero playing black and coming up with a new idea, castling queenside and pushing the h pawn.

```
[Title "Stockfish vs AlphaZero"]
[fen ""]

1.e4 e5 2.Nf3 Nc6 3.Bb5 f5 4.Nc3 fxe4 5.Nxe4 Nf6 6.Nxf6+ Qxf6 7.Qe2 Be7 8.Bxc6 bxc6 9.Nxe5 Bb7 10.O-O O-O-O 11.d3 Rde8 12.Nc4 h5 13.Qe3 h4 14.Qh3 Kb8 15.Bd2 d5 16.Bc3 d4 17.Bd2 Bc8 18.Qf3 Qxf3 19.gxf3 Be6

```

And then with AlphaZero playing white and again getting very aggressive

```
[Title "AlphaZero vs Stockfish"]
[fen ""]

1.e4 e5 2.Nf3 Nc6 3.Bb5 f5 4.d3 fxe4 5.dxe4 Nf6 6.O-O d6 7.Bc4 Bg4 8.h3 Bh5 9.Nc3 Qd7 10.Nd5 O-O-O 11.Qd3 Kb8 12.a4 Ne7 13.Ng5 Bg6 14.Nxf6 gxf6 15.Nf7 Bxf7 16.Bxf7 h5 17.a5 a6 18.Qb3 Nc6 19.Be3 Bh6 20.Be6 Qg7 21.Bd5 Qd7 22.Ra3 Bxe3 23.fxe3

```

Then there are these two YouTube videos where GM Melik Khachiyan analyses some of his games in the Schlieman -

Part 1
Part 2

Finally Kingscrusher analyses the historic game Bobby Fischer vs Milan Matulovic - Herceg Novi Blitz 1970 on his YouTube channel.
> 2 votes

# Answer
You could find that by googling "e4 e5 Nf3 Nc6 Bb5 f5"

Here is the first result

Anyway the Ruy Lopez (and many other openings) improve your chess overall if you play the strategically rich mainlines, not because there's any magic behind **1.e4 e5 2.Nf3 Nc6 3.Bb5** that will make you a better player. The line you suggest is great and will leave you with pretty fun games, but don't expect many strategical subtilties on it.
> 1 votes

---
Tags: opening, ruy-lopez
---


# Question
Title: Does anyone know if there is an English translation of this book?
It is a book written by Boris Zlotnik. I found some books from him in search, but I'm not sure whether the same book. Some titles with chess course vol.1, vol2., etc..

# Answer
It is hard to prove that something does not exist, but I read and speak Russian, and I just looked at that book in Russian. It deals a lot with tabias of various openings, and resulting middlegames.

The only book of his in English I could find is "Chess : Knowledge, Training, Mastery", and that is definitely a different book, as I also have that in Russian: "Шахматы - Наука, Опыт, Мастерство (1990)" (strictly translated as "Chess: Science, Experience, Mastery").

Lastly, I found a site that seemed to say that it was only available in Russian, which I tend to agree with after researching it. Interestingly, he has a two-volume series in Spanish though, and one more in Spanish.
> 4 votes

# Answer
Hold on, the translation is coming out in December!

https://www.amazon.com/Zlotniks-Middlegame-Manual-Structures-Manoeuvres/dp/9056919261/ref=sr\_1\_1?dchild=1&qid=1595944036&refinements=p\_27%3ABoris+Zlotnik&s=books&sr=1-1
> 3 votes

---
Tags: books
---


title: Chess engine with no evaluation

text:
# Question
Title: Chess engine with no evaluation
One of the most difficult parts of a chess engine is the evaluation function. Handcrafted evaluation functions are very long and complicated, while NN evaluations are hard to make and train. That's why I was wondering whether an implementation of a chess engine with no evaluation function would be possible. Search algorithms like MCTS don't need an explicit one, as they can rely on random playouts.

Could a similar approach be used to create a chess engine with a random search algorithm, which averages the results from those random games and optimally reach to the best move?

Theoretically, it should converge to the optimal solution (minimax), right? Of course it would be for testing and experimentation purposes, but I think with a good implementation of the algorithm, it should play at least at almost master level. I would implement it on Golang, as it would be easier to implement concurrency/parallelism. What are your thoughts on this?

# Answer
> 7 votes
I have tried using MCTS before for a chess engine and the results were not very good. The problem was that the results when playing out a game with only random moves were basically just that: random. Most of the results would only be reached after over 100 plies so the initial position had little to do with the result.

I had better results when I cutoff the tree after x plies where x would be somewhere between 20 and 50 and using a simple evaluation function for that position. But then you would be relying on a evaluation function again.

# Answer
> 6 votes
The number of board states is on the order of 10^45. That's within a few orders of magnitude of the number of water molecules in the Earth's oceans. So solving chess by exhaustively searching the possible board states is not currently considered computationally feasible.

Instead you're proposing Monte Carlo Tree Search. In this approach, you would use random roll-outs (i.e. playing a game to the end by making random moves, then seeing if you won). This is equivalent to randomly choosing a branch of the possible future board states and seeing if it results in a win, and from that, making moves that you estimate to be likely to lead to victory.

For this to work, given the scale of the possible board states, you need a sampling algorithm that is very thorough and very fast, and most importantly, *very representative*. Unfortunately, the surface you're trying to optimize over is not very smooth: even the best board position can be turned into a loss with a couple bonehead moves, and if you're sampling random future board states (the hallmark of Monte Carlo, vs. exhaustive, search methods), you have no way to know whether what you have sampled is representative of the entire branch, or if you just picked a rollout that included some really bad plays (or conversely, one where your opponent did something dumb that gave you a needlessly rosy view of your odds).

That's the entire point of the evaluation function: you estimate the value of a set of intermediate board states, which you can more thoroughly explore within a reasonable future-turn horizon. (Until you reach the endgame, where you can realistically do exhaustive search.)

Note that MCTS *is* in a sense learning an evaluation function: instead of an explicitly stated value for a board state, you're keeping statistics on the number of times a sequence of random moves from that board state have resulted in wins/losses. The problem is, because of how distant the eventual win/loss is from most board states, and because of your inevitable computational limits, you're learning a *pretty bad* evaluation function.

If your sampling rate was high enough, this could work; but with no evaluation function (or way to approximate an evaluation function, like a neural network), you're going to spend far too much of your time evaluating obviously bad plays and not learning anything actionable. It just isn't computationally feasible given the numbers involved.

# Answer
> 0 votes
MCTS is over-hyped. In general to make a computer player for such turn-based abstract games, you would need to use negamax/minimax plus alpha-beta pruning (see this post for an explanation of its correctness), together with a couple of heuristics:

* **Position-evaluation functions**: Estimates the true value of the given position. Must be used at the leaves of the search tree, but may also be used elsewhere. In chess, material imbalance is a reasonable first-order estimate, and costs almost nothing to compute, but a very big reason that StockFish has such good performance is that it has an far more intricate evaluation function than just computing material imbalance; it counts in king danger, passed pawns, control of open files, obstructed pieces, and many more things.
* **Expansion heuristic**: Decides which lines of play to search, possibly using a position-evaluation function to do so. This includes quiescence search (to avoid the horizon effect), which for chess typically means to search deeper for captures and checks.
* **Move-ordering heuristic**: Decides the order in which to search lines of play from each position, possibly relying on a position-evaluation function as well. This includes iterative-deepening, killer heuristic, null-move heuristic and so on. For chess, it is often useful to search 'attacking' moves first, besides the other general heuristics.
* **Opening book**: Decides the first few moves. It is computationally intensive to search deep, but one can do so on supercomputers and simply store the resulting evaluations of positions near the start in an opening book in the program. If you take a look at StockFish on Lichess, you can see that it indeed has such an opening book.

If you think about it, attempting to use MCTS to decide which move is best will perform approximately the same as a depth-1 greedy algorithm even if you have a material imbalance evaluation function at the leaves of the MC search tree, and actually a bit worse due to the random noise! To assist your intuition, consider a typical position that is win-in-10, and note that the winning strategy is typically sharp; the player that can win cannot make random moves and expect to win! MCTS is completely blind to that.

Moreover, as *Tiercelet* already mentioned, MCTS itself can be considered to be equivalent to using depth-1 search with a super lousy evaluation function (return the average position value after random plays)! Anyone who is not a beginner at chess can design a better evaluation function.

MCTS is bad not just for chess. Even for optimization problems where the objective function does not change drastically upon perturbing the state, a good heuristic would beat any pure MCTS algorithm hands down. Of course, to get a good heuristic you need a human to design it. So if you do not have any humans around you might have no choice but to use dumb algorithms like MCTS or simulated annealing with reheating.

The point is, with the same amount of computing resources, MCTS will always perform much more poorly than a reasonably good heuristic, regardless of the optimization/search problem.

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Tags: engines
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# Question
Title: What are the most common checks in chess?
I read somewhere that to optimize move generation for a chess engine it's good to have fast detection of position where one side is checked (to eliminate illegal moves).

The author suggested that check detection could be improved slightly by having the code test for common checks which happen first. However, they didn't give anymore insight than that.

I reasoned that my code for check detection should look for checks coming from the opponent's side of the board. Other than that though I couldn't think of anything else. This lead me to ask the following question:

> **What are the most common checks which occur in chess?**

For example, are checks from queens more likely than checks from knights? Are certain diagonals more prone to checks than files?

*Advice for methods I could use to answer this question in the comments would also be appreciated*

# Answer
> 2 votes
> What are the most common checks which occur in chess?

Back rank checks (and check mates) must be the number one. I would suspect that bishop checks from h2/h7 on the castled king should also be up there in the top 10 if not number two.

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Tags: engines, software, check
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# Question
Title: Need help finding a tactics database with motifs
I am trying to make a neural network which could determine what chess tactic is present in a position. For this, I need to have a database of chess tactics labelled with correct motifs.

A similar question was asked a few years ago, but it is not particularly useful. Is there any website which has such database?

# Answer
Try the chess.com website. They have plenty of resources available. They also have a fully trained neural net which evaluated and scores your games with the aim to improve the player and facilitate their learning process.
> 1 votes

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Tags: engines, computer-chess, database
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