title: Issue with Magic Bitboards

text:
# Question
Title: Issue with Magic Bitboards
I have a implemented a similar version to the example given on the chess programming wiki by Tord Romstad.

I just changed the random generation and stored the magics in an array. I even kept the old count\_1s and didn't use any modern instructions.

If I test the magics on a bitboard it always give wrong results. I assume there is some problem with the transform function.

Here is the code :

```
#include <random>
#include <iostream>
#include <array>
#include <stdlib.h>

std::array<uint64_t, 64> ROOK_MASK, BISHOP_MASK;
std::array<uint64_t, 64> ROOK_MAGIC, BISHOP_MAGIC;
std::array<std::array<uint64_t, 4096>, 64> ROOK_MAGIC_LOOKUP, BISHOP_MAGIC_LOOKUP;

std::random_device rd;
std::uniform_int_distribution<uint64_t> dist(0, UINT64_MAX);

void printBitboard(const uint64_t& bb)
{
    uint64_t mask = 0;
    for (int rank = 7; rank >= 0; rank--) {
        for (int file = 0; file < 8; file++) {
            int square = rank * 8 + file;
            mask = 1ULL << square;
            if (bb & mask) {
                std::cout << '1';
            }
            else {
                std::cout << '0';
            }
        }
        std::cout << std::endl;
    }
    std::cout << "______________" << std::endl << std::endl;
}

uint64_t random_uint64_fewbits()
{
    return dist(rd) & dist(rd) & dist(rd);
}

int count_1s(uint64_t b) {
    int r;
    for (r = 0; b; r++, b &= b - 1);
    return r;
}

const int BitTable[64] = {
  63, 30, 3, 32, 25, 41, 22, 33, 15, 50, 42, 13, 11, 53, 19, 34, 61, 29, 2,
  51, 21, 43, 45, 10, 18, 47, 1, 54, 9, 57, 0, 35, 62, 31, 40, 4, 49, 5, 52,
  26, 60, 6, 23, 44, 46, 27, 56, 16, 7, 39, 48, 24, 59, 14, 12, 55, 38, 28,
  58, 20, 37, 17, 36, 8
};

int pop_1st_bit(uint64_t* bb) {
    uint64_t b = *bb ^ (*bb - 1);
    unsigned int fold = (unsigned)((b & 0xffffffff) ^ (b >> 32));
    *bb &= (*bb - 1);
    return BitTable[(fold * 0x783a9b23) >> 26];
}

uint64_t index_to_uint64(int index, int bits, uint64_t m) {
    int i, j;
    uint64_t result = 0ULL;
    for (i = 0; i < bits; i++) {
        j = pop_1st_bit(&m);
        if (index & (1 << i)) result |= (1ULL << j);
    }
    return result;
}

uint64_t rmask(int sq) {
    uint64_t result = 0ULL;
    int rk = sq / 8, fl = sq % 8, r, f;
    for (r = rk + 1; r <= 6; r++) result |= (1ULL << (fl + r * 8));
    for (r = rk - 1; r >= 1; r--) result |= (1ULL << (fl + r * 8));
    for (f = fl + 1; f <= 6; f++) result |= (1ULL << (f + rk * 8));
    for (f = fl - 1; f >= 1; f--) result |= (1ULL << (f + rk * 8));
    return result;
}

uint64_t bmask(int sq) {
    uint64_t result = 0ULL;
    int rk = sq / 8, fl = sq % 8, r, f;
    for (r = rk + 1, f = fl + 1; r <= 6 && f <= 6; r++, f++) result |= (1ULL << (f + r * 8));
    for (r = rk + 1, f = fl - 1; r <= 6 && f >= 1; r++, f--) result |= (1ULL << (f + r * 8));
    for (r = rk - 1, f = fl + 1; r >= 1 && f <= 6; r--, f++) result |= (1ULL << (f + r * 8));
    for (r = rk - 1, f = fl - 1; r >= 1 && f >= 1; r--, f--) result |= (1ULL << (f + r * 8));
    return result;
}

uint64_t ratt(int sq, uint64_t block) {
    uint64_t result = 0ULL;
    int rk = sq / 8, fl = sq % 8, r, f;
    for (r = rk + 1; r <= 7; r++) {
        result |= (1ULL << (fl + r * 8));
        if (block & (1ULL << (fl + r * 8))) break;
    }
    for (r = rk - 1; r >= 0; r--) {
        result |= (1ULL << (fl + r * 8));
        if (block & (1ULL << (fl + r * 8))) break;
    }
    for (f = fl + 1; f <= 7; f++) {
        result |= (1ULL << (f + rk * 8));
        if (block & (1ULL << (f + rk * 8))) break;
    }
    for (f = fl - 1; f >= 0; f--) {
        result |= (1ULL << (f + rk * 8));
        if (block & (1ULL << (f + rk * 8))) break;
    }
    return result;
}

uint64_t batt(int sq, uint64_t block) {
    uint64_t result = 0ULL;
    int rk = sq / 8, fl = sq % 8, r, f;
    for (r = rk + 1, f = fl + 1; r <= 7 && f <= 7; r++, f++) {
        result |= (1ULL << (f + r * 8));
        if (block & (1ULL << (f + r * 8))) break;
    }
    for (r = rk + 1, f = fl - 1; r <= 7 && f >= 0; r++, f--) {
        result |= (1ULL << (f + r * 8));
        if (block & (1ULL << (f + r * 8))) break;
    }
    for (r = rk - 1, f = fl + 1; r >= 0 && f <= 7; r--, f++) {
        result |= (1ULL << (f + r * 8));
        if (block & (1ULL << (f + r * 8))) break;
    }
    for (r = rk - 1, f = fl - 1; r >= 0 && f >= 0; r--, f--) {
        result |= (1ULL << (f + r * 8));
        if (block & (1ULL << (f + r * 8))) break;
    }
    return result;
}

int transform(uint64_t b, uint64_t magic, int bits) {
    return (int)((b * magic) >> (64 - bits));
}

bool find_magic(int sq, int m, bool bishop) {
    uint64_t mask, b[4096], a[4096], used[4096], magic;
    int i, j, k, n;
    bool fail = false;

    mask = bishop ? bmask(sq) : rmask(sq);
    n = count_1s(mask);

    for (i = 0; i < (1 << n); i++) {
        b[i] = index_to_uint64(i, n, mask);
        a[i] = bishop ? batt(sq, b[i]) : ratt(sq, b[i]);
    }
    for (k = 0; k < 100000000; k++) {
        fail = false;
        magic = random_uint64_fewbits();
        if (count_1s((mask * magic) & 0xFF00000000000000ULL) < 6) continue;
        for (i = 0; i < 4096; i++) used[i] = 0ULL;
        for (i = 0;!fail && i < (1 << n); i++) {
            j = transform(b[i], magic, m);
            if (used[j] == 0ULL) used[j] = a[i];
            else if (used[j] != a[i]) fail = true;
        }
        if (!fail)
        {
            if (bishop)
            {
                BISHOP_MAGIC[sq] = magic;
                std::memcpy(BISHOP_MAGIC_LOOKUP[sq].data(), used, sizeof(used));
            }
            else
            {
                ROOK_MAGIC[sq] = magic;
                std::memcpy(ROOK_MAGIC_LOOKUP[sq].data(), used, sizeof(used));
            }

            return true;
        }

    }
    return false;
}

int RBits[64] = {
  12, 11, 11, 11, 11, 11, 11, 12,
  11, 10, 10, 10, 10, 10, 10, 11,
  11, 10, 10, 10, 10, 10, 10, 11,
  11, 10, 10, 10, 10, 10, 10, 11,
  11, 10, 10, 10, 10, 10, 10, 11,
  11, 10, 10, 10, 10, 10, 10, 11,
  11, 10, 10, 10, 10, 10, 10, 11,
  12, 11, 11, 11, 11, 11, 11, 12
};

int BBits[64] = {
  6, 5, 5, 5, 5, 5, 5, 6,
  5, 5, 5, 5, 5, 5, 5, 5,
  5, 5, 7, 7, 7, 7, 5, 5,
  5, 5, 7, 9, 9, 7, 5, 5,
  5, 5, 7, 9, 9, 7, 5, 5,
  5, 5, 7, 7, 7, 7, 5, 5,
  5, 5, 5, 5, 5, 5, 5, 5,
  6, 5, 5, 5, 5, 5, 5, 6
};

uint64_t getRookMoves(const uint64_t& allBlockers, const int& square)
{
    std::cout << "All Blockers" << std::endl;
    printBitboard(allBlockers);

    uint64_t maskedBlocker = ROOK_MASK[square] & allBlockers & (~(0b1ULL << square));

    std::cout << "Masked Blocker" << std::endl;
    printBitboard(maskedBlocker);

    int index = transform(maskedBlocker,ROOK_MASK[square], RBits[square]);

    uint64_t attacks = ROOK_MAGIC_LOOKUP[square][index];

    std::cout << "Attacks from Magics" << std::endl;
    printBitboard(attacks);

    std::cout << "Correct Attacks" << std::endl;
    printBitboard(ratt(square, maskedBlocker));
    return attacks;
}

void main()
{
    //fill MASKS
    for (size_t square = 0; square < 64; square++)
    {
        ROOK_MASK[square] = rmask(square);

        BISHOP_MASK[square] = bmask(square);
    }

    //find magics for each square (bishop + rook)
    for (size_t square = 0; square < 64; square++)
    {
        bool r = find_magic(square, RBits[square],false);
        bool b = find_magic(square, BBits[square], true);
        if (!(r && b))
        {
            std::cout << "ERROR FINDING MAGICS"<<std::endl;
        }
    }
    std::cout << "FINISHED FINDING MAGICS" << std::endl;

    //Test for bitboard 0xa07c04000154bc28 on square 0 / a1
    getRookMoves(0xa07c04000154bc28, 0);
}

```

The only thing changed from the original is the `random_uint64_fewbits` and the `find_magic` function.

In the `getRookMoves` i am testing my results. I test wether the Magic-Generation produces the same output as the `ratt` function. Example :

```
Attacks from Magics
00000000
00000000
00000000
10000000
10000000
10000000
10000000
01000000

Correct Attacks
00000000
00000000
00000000
00000000
10000000
10000000
10000000
01110000

```

They don't match so there is some error, I was not able to find.

If someone has some other resource for finding and testing magic bitboard, please share them with me.

# Answer
After some more investigation, if found out that the issue was in the `GetRookMoves` function. The issue was that i was using the `ROOK_MASK` as parameter and not the `ROOK_MAGIC` array.

```
uint64_t getRookMoves(const uint64_t& allBlockers, const int& square)
{
    std::cout << "All Blockers" << std::endl;
    printBitboard(allBlockers);

    uint64_t maskedBlocker = ROOK_MASK[square] & allBlockers & (~(0b1ULL << square));

    std::cout << "Masked Blocker" << std::endl;
    printBitboard(maskedBlocker);

    int index = transform(maskedBlocker,ROOK_MAGIC[square], RBits[square]);

    uint64_t attacks = ROOK_MAGIC_LOOKUP[square][index];

    std::cout << "Attacks from Magics" << std::endl;
    printBitboard(attacks);

    std::cout << "Correct Attacks" << std::endl;
    printBitboard(ratt(square, maskedBlocker));
    return attacks;
}

```

This is the new `getRookMoves` function. I leave the question online beacuse, i think it can be a good example how to use magics.
> 3 votes

---
Tags: engines, programming, bitboard
---


title: How much is the value of the wizard?

text:
# Question
Title: How much is the value of the wizard?
I came up with a new chess piece called the "Wizard".What it does basically is that it can switch places with any piece(except pawns) and for 1 move it has the attributes of the switched piece but cannot move for 1 move.He can deliver check,checkmate etc..For example suppose we have a knight at a5.If the wizard switches places with the knight 19.W=Na5 he will get the attributes of the knight.Then the wizard will continue to act as a Knight and we will be able to use him again on move 21.Oh he remains frozen meaning you cannot move him on move 20.

Also you cannot switch places with a piece under a absolute pin.And the wizard cannot move if he is under a absolute pin.

How much would that piece worth?

# Answer
Considering that the Queen has the combined power of a rook and knight and her value is the combined value of the rook and knight; perhaps the wizard should have the combined value of all pieces since he potentially has the movement capabilities of all pieces?

**Edit:** Considering that a wizard & minor piece cannot mate a lone king, as another user pointed out; perhaps the wizard should have the combined value of all same-coloured pieces *still on the board*?
> 1 votes

---
Tags: chess-variants, pieces, point-value, unorthodox-pieces
---


title: Theory behind the Cow Opening

text:
# Question
Title: Theory behind the Cow Opening
Recently IM Eric Rosen played the Cow Opening every game in Titled Tuesday, scoring 6.5/11 and increasing his rating. He streamed it and put it on YouTube. It is a Hippo style opening which can play as both black and white. The structure you are aiming for is this:

```
[Title "Cow Opening"]
[fen ""]
[Startply "15"]

1. d3 null 2. e3 null 3. Nd2 null 4. Ne2 null 5. Nb3 null 6. Ng3 null 7. Be2 null 8. Bd2

```

What are the ideas behind the opening apart from confusing the opponent and / or just surviving? Rosen seemed to do quite well with it.?

# Answer
From what I can tell, this opening will probably require white to go for either c4 or f4 to break open black's center (assuming black takes the center, which black definitely should). Stockfish suggests for black to just take the center and develop normally, though it does seem to think going for h5 after the knights have gone to d2 and e2 is the best move.

However, black can still get a -1.5ish position just by playing solidly and castling, so if someone were to play this against me I would just go for a setup like this:

```
[FEN "r2q1rk1/pp2bppp/2n1bn2/2ppp3/8/1N1PP1N1/PPPBBPPP/R2Q1RK1 b - - 7 9"]

```

From here I would probably go either b6 a5 or a5 right away then try to break open the queenside.
> 3 votes

# Answer
The theory behind it is to take the opponent completely out of book very early, so they have to spend time thinking on move 1. And the opening may also feed the opponent's paranoia. "What the heck? Is this a trap?" There's no trap.

It's hard to refute openings like this, but it is very tempting to try. And, as Ben Finegold says "trying is the first step to failure".
> 4 votes

# Answer
I believe that Anna Cramling invented this in jest and challenged Eric to play it in a speed event (Titled Tuesday) It creates no threats, and I imagine that almost any reasonable system of development would at least equalise. Meeting it for the first time in a speed game, however, one might waste time looking for a refutation, which I think did happen once or twice.
> 3 votes

---
Tags: opening, theory
---


# Question
Title: Is it legal, after touching a piece to move other pieces for the purpose of visualization
Imagine the following scenario:

I am playing as white and on my first move I:

1. Touch my b1 knight without moving it or pressing the clock
2. Move one of my opponents pieces
3. Move one of my pieces (excluding my b1 Knight)
4. Repeat 2-3 arbitrary number of times
5. Once satisfied with seeing the line played out I return all piece back to their original positions
6. Move my touched b1 knight to a3 or c3
7. Press the clock

Have I broken any FIDE rules?

My instinct is that this is legal since:

> 7.5.1 An illegal move is completed once the player has pressed his/her clock.

# Answer
> 2 votes
The relevant § are the following:

§4 Touch-move: You must now move your Nb1 and (by §4.7) play it to the square you released it first, which makes the whole analyzing part by you a bit pointless.

§11.3.1 Surplus info: Analyzing a game surely counts as a source of "info" in the sense of this § (even if the § explicitely mentions analyzing on *another* board, but §0.2 Rule by analogy can be applied).

§11.5/11.1 Catch-them-all: A newbie I might let go with a stern warning under the assumption there was a severe misunderstanding of tournament rules. Anyone else will get the book thrown at with superluminal speed, for obvious trolling.

---
Tags: rules, fide
---


# Question
Title: Do top players get discouraged if they cannot beat the best player in the world?
Magnus Carlsen has been the best player in the world for a decade. The other top players try, but they haven't been able to beat Carlsen, who's consistently 50+ elo above them.

Do the other top players find this discouraging in the same way most people find playing against computers (and getting consistently crushed) discouraging? One could argue that not being able to compete with Carlsen is not a problem for the vast majority of chess players, but that does not apply to elite GMs whose job is to compete with Carlsen. If they do find it discouraging, how do they stay motivated?

Nothing unique about Carlsen on this - it could also apply to Kasparov, Fischer, or any other era in the past when one player was so obviously better than everyone else that he's the favorite no matter what tournament he plays in.

I'm especially interested in quotes from GMs about this.

# Answer
> 4 votes
I'm sure Carlsen's colleagues are a little discouraged with his dominance, but they didn't get to their current level by giving up against a (seemingly) stronger opponent. All of them must have had setbacks and breakthroughs in their long journey through the master titles and 2700+ club. Giving up now is the worst thing a top tier player can do (and someone with that defeatist attitude would never reach their current level anyways).

Nearly all of them have defeated Carlsen at least once. All of them have played engine-level chess at some games in their careers. So they know 'better-than-Magnus' chess is within their potential. The rest is a matter of consistency.

Playing someone slightly better than oneself is also a huge learning experience. Karpov on becoming world champion without playing Fischer. Magnus' opponents have probably learned a great deal about their weaknesses and psychology.

And the future isn't certain. After years of dominance, Magnus performed uncharacteristically poorly in Norway Chess 2023. Carlsen is human, and he won't be the best chess player forever. So the others just have to keep working. The satisfaction of defeating Carlsen is already emotionally overwhelming. Just imagine the satisfaction of being the first to surpass him, after 10+ years at the top. It can only be earned by one.

---
Tags: history, psychology, grandmaster, super-grandmaster
---


# Question
Title: In what ways is it the best to use a computer in correspondence chess?
I have only recently started correspondence chess and I have read that engines are allowed in correspondence chess. I definitely do know that the world champions of correspondence chess have said that using engines to a 100% degree is a bad idea. My question is this: What is the most efficient way to use engines in this format of chess? Any experiences would be helpful!

# Answer
Obviously, as long as they are permitted within the rules of the organization, here is how I would use a computer.

First, realize that different programs are better at different things, and I will divide them into two categories. I heard GMs Peter Svidler and Jan Gustafsson discuss this during the Firouzja-Carlsen game just yesterday.

The first program is for opening play, and that is where Leela shines. I have not had much experience with this program, but Jan mentioned that it can, apparently, blunder at times. They both agreed that Stockfish is still the king of analyzing in the middlegame. I watch a lot of relays of top tournaments, and I follow along with Stockfish, and it is currently the best program out there for the middlegame, and the best part is that it is free.

The next thing is that in most circumstances, I only look at the top two lines (in ChessBase, you can click the little plus/minus sign in the engine box to add/remove the number of lines). I would probably increase this to the top 5 lines for correspondence since there may be a line that fits in better with what you are trying to do, so you can, at least, know to explore it.

Next, in the opening, it helps if you have a good understanding of the opening pawn structure, and the typical plans that are played. As you get into the opening, look at a bunch of GM games from a database to see what they have done before you decide on your moves. Have Stockfish going while looking at them...you never know what you might find if it pops up an unusual eval.

Lastly, and the stronger you are, the easier this is, and the better you will be at it, but you want to play "advanced chess". "Advanced chess" is term for using both the computer and your knowledge to pick the best move. In its infancy, Anand was considered the best at this, and there were a few tournaments where these top players were allowed to use a computer. Here is an article. As part of this cyborg play, and this is the key, you want to force in certain series of the computer's best moves or even some of your own human moves, so, in essence, the program only starts analyzing from that point.

For example, if you and I are playing and we are on move 28, and you just let your computer analyze from there, it may analyze out to move 38. Not bad, but if I am able to force in 7 likely moves based on my 40 years' of experience and the computer's evaluation along the way, and only then let it think uninterrupted, I start at move 35, and might get to move 45.

If you are evaluating a position based on the end result at move 38, but I am evaluating it based on move 45, 7 moves later; I am much more likely to be successful, and win the game.

That is how I would use one if I played correspondence chess. Frankly, I am too impatient so I was never into correspondence in the old days of postcards, but the advent of computers really turned it into more machine versus machine, so that really killed any chance I would get into this in the future; but to each his own.
> 7 votes

# Answer
This is by no means complete, but here's a few things.

1. Use at least 2 engines. More different is generally better. Lc0 and SF would be an obvious pair.
2. Especially with leela, look at the point of view of the engine. Dig into disagreements.
3. Realize most of your games will be draws
4. Make sure you have tuned your engines for long time control. For leela, that typically means using a bigger net since you will have plenty of time to get nodes.
> 4 votes

# Answer
I feel a bit like I'm giving away my secrets, but here we go

1. Learn how to get the most performance out of your computer setup. For example, you can run analysis 1) in the browser on chess.com or lichess, 2) using a downloaded version of stockfish connected to your GUI, or 3) compile an optimized build of stockfish from source code for your specific hardware. Those are in order of increasing complexity and you gain effective ELO with each step, with diminishing returns as you increase complexity. At the least I'd recommend staying up-to-date with the latest releases.
2. Don't use engine parameter defaults. For example, things like the number of threads and the hashtable size need to be increased for longer analysis and for maximal search speed. On my primary analysis machine, I have 3 threads for lc0 (one per GPU + one extra) and 21 threads for stockfish, with a 16GB hashtable for stockfish. The total number of threads you use should be the number of cores your system reports. In my example above, I have 12 cores with hyperthreading and the OS reports 24 cores.
3. Use syzygy tablebases. All the 6-man positions are a few hundred GB IIRC. I'd also suggest a handful of the most popular 7-man positions and store those locally too. Store these on a fast SSD. Learn how to configure your engine to use these, and how to verify that they're working. Having these available will sometimes drastically change the evaluation of late middlegame positions because the engine will have an absolutely true evaluation of some endgame positions as opposed to using its heuristics to evaluate. This will prevent going into lines that look good from the engine's perspective but are tablebase draws, and could lead you toward positions that are favorable but which the engine has a hard time seeing the benefit of.
4. Track the current engine evaluation of every game you're playing, and spend more time on games where the evaluation is in your favor. The eval tells you how hard to work analyzing variations. For example, if I see +1.3 for me on move 22, I'm going to try to look at dozens of lines into the late middlegame or early endgame if I can to see if I can find lines where the eval holds, or better yet, increases, as I go deeper. The hard truth is that often you'll see the +1.3 advantage just evaporate as you play on, so it's critical to explore and decide if you think you can find lines where your perceived advantage does not vanish.
5. The corollary to the above is basically don't spend any time on positions that are 0.00 eval. I'd say don't offer or accept a draw in these positions, but choose your move from the 0.00 options and make it after double and triple checking that the position on the board and your move match what you analyzed. If your opponent wants a draw, they have to not mess up and get to a tablebase position, 50 move rule position, or find a threefold repetition and can then automatically claim a draw. I've gotten one or two wins in drawn 0.00 positions where my opponent made a mistake. And frankly, all wins in chess are a mistake on your opponents part because its all probably a theoretical draw from move one. So you might as well play in any 0.00 position because the starting position is probably theoretically 0.00 and no one has qualms about starting a game. If you play move one because you think you have a chance at a win, then you should think you have a chance at a win in any 0.00 position.
6. Dive into the details of disagreements between engines. If lc0 and stockfish see a position drastically differently, play out the lines and see which engine changes its mind first as you go deeper and deeper. You'll sometimes find that one engine or the other misses a critical move and only sees it when you get closer or in some cases after you've played the move. Use this to your advantage: once you've resolved the discrepancies by going deeper, you have a better true evaluation of the position, while your opponent may not have as good of a picture, and as they play on thinking they are okay according to their engine, you will surprise them with a line their engine missed.
7. Use MultiPV. This is one no one talks about. Engines will give you their top N lines and sort them by evaluation. So in a position where there are several good moves, I'll start with many lines and let the engine crank for a while. I'll mentally cluster the top moves and reduce the PV to just consider them. For example, if I do a PV=5 analysis to depth 30 and see evals of {0.47, 0.45, 0.42, 0.22, 0.16}, I'll notice that the top three cluster together, then the next moves down come after a larger gap in eval. So then I'll reduce the PV to three, and let the computer crank to more depth on just those three to see if it will clearly separate those three and if one is clearly better than the others. If not, I'll explore all three in depth and decide which line I like.
8. Using the computer just for record keeping of your analysis is huge benefit to your game. I write extensive comments in my games using my GUI, including my impressions of the evaluation, how many alternate lines I think I should consider, and if/when I think my opponent missed something or played an inaccuracy.
9. Analyze past games for opening ideas. All the ICCF PGN files are available and can be made into one big database, which can then be viewed in "Show Statistics" mode in the Scid software (for example, there's lots of ways to do this). This shows me immediately what's been played, how relatively popular different opening moves are, and lets me dig into opening lines in depth. If a line is popular but statistically bad for one side, I'll often delve deeper to see if there is an unpopular sideline that is more favorable. For example, there are lines in the Najdorf Poisoned Pawn that are statistically overall bad for black, but if black plays the second most popular move at the right moments, he is fine and will maintain equality. I also keep a separate file of just my completed games (and my current ongoing games). I'll look to my completed games for guidance, e.g., if a move looks statistically bad in the opening database but I've drawn with it many times, I'm more confident that its okay to play (but I'll always check variations to make sure I won't be unhappily surprised).
10. Use your opening database and engine to find the perfect moment to uncork a novelty. If you see a move has not been played in a previous position and its top or close to the top of engine recommendations, you can consider going for it and bringing your opponent into previously uncharted territory. In my opinion, the earlier you deviate from the database the better, because less about the structure of the position is cemented.
> 2 votes

---
Tags: engines, analysis, correspondence-chess
---


title: What makes some players so good?

text:
# Question
Title: What makes some players so good?
Why are some players seemingly 'naturally' better at chess than the majority?

Of course intelligence plays a part, but there are plenty of 'clever' people that are not very good at chess and some 'not clever' people who are chess prodigies.

What exactly about these people/their upbringing makes them this way and why is it so unheard of for people who are not naturally skilled (eg. people who haven't won tournaments as children) to become a top player?

# Answer
> Of course intelligence plays a part, but there are plenty of 'clever' people that are not very good at chess and some 'not clever' people who are chess prodigies.

IQ is generally regarded as having 3 or more components, visuo-spatial ability, verbal reasoning and numerical/mathematical ability. People differ in the amounts of each of these components. Pattern recognition, which has a lot to do with visuo-spatial ability, is the key factor for chess ability. So, somebody could be very high in visuo-spatial ability and low in the other components thereby appearing to be not clever yet very good at chess, and vice versa.

> Why are some players seemingly 'naturally' better at chess than the majority?

I think the key to being very good at chess is to love it. If you really love it then what looks like hard work to other people will look like having fun to you. You will work hard without realising it and become very good. That said, you are unlikely to enjoy chess unless you start with good visuo-spatial ability / pattern recognition. So, that probably comes first.
> 15 votes

# Answer
Of all positive chess features, by far the most characteristic and important is the chess-professional memory. In a contrasts to amateurs, the top players remember tens of thousand of chess patterns, of whole games, etc.

The research studies showed that in the case of the extraordinary talented players the chess info goes straight to the stable part (and stays there!) rather than to the temporary part of the brain's memory storage.

A time ago, after a neat combination I won a game against a raw beginner, and it was all that there was to it. To my surprise, my partner was truly impressed and he went from one person to another around the place, and he was showing the game to the others; he was also able to show the combination by setting the position where that sequence started. This shows that that youngster had a huge chess potential. (No, I never met my partner again, I cannot provide any follow-up).
> 6 votes

# Answer
I once had a book by GM Jonathan Levitt, titled *Genius in Chess*. He describes how he played a series of games against Alexei Shirov, got demolished, and while nursing his ego he asked himself the question: just why was Shirov rated 200 points above him?

Eventually he came up with the following:

* 50 points: superior physical condition
* 50 points: superior opening preparation
* 50 points: superior motivation
* 50 points: talent

He resolved to work on the first three points. Result: he dropped from 2500 to 2450, while Shirov shot above 2700.

**Conclusion: at top level, talent separates the great from the very good.**

Here's a quote to this effect about Carlsen, illustrating the effect of talent:

> But Kasparov says Carlsen's mastery is rooted in a "deep intuitive sense no computer can teach" and that his pupil "has a natural feel for where to place the pieces." According to Kasparov, Carlsen has a knack for sensing the potential energy in each move, even if its ultimate effect is too far away for anyone - even a computer - to calculate. In the grand-master commentary room, where chess's clerisy gather to analyze play, the experts did not even consider several of Carlsen's moves during his game with Kramnik until they saw them and realized they were perfect. "It's hard to explain," Carlsen says. "Sometimes a move just feels right."
> 6 votes

# Answer
Actually, quite a lot of serious scientific research went into this. A major component seems to be: deliberate practice.

See this great Veritasium video: https://www.youtube.com/watch?v=5eW6Eagr9XA
> 2 votes

# Answer
Anything you learn while young, you learn better and deeper than something you learn as an adult.

Consider the way we learn languages.

As a child we listen and we learn. And later we just **know** what is the right way to say things. We cannot explain it, beyond "It just sounds right".

Compare that to learning a foreign language as an adult. You have to learn rules that doesn't make sense, and that you constantly forget. You learn vocabulary but will usually mess up the subtle distinctions. Trying to keep everything straight while talking is a constant battle.

Most human children have a part of the brain that is will eagerly grasp any language it comes across and learn it. Language learned this way become part of the permanent fundamental wiring of the brain.

Most human children, probably, do not have a part of the brain that is eager to learn chess.

However, **some** children get interested in chess at an early stage while the brain is still very flexible, and they repurpose other parts of the brain to process chess. Parts of their vision center is now a chess vision center. Parts of their memory is a dedicated chess position memory. Some part of something becomes a dedicated chess move analyzer.

All this is part of the permanent fundamental wiring of their brains, below the level of reasoning.

As adults they will "just know" that some positions are strong and others are weak. They "just know" what will turn their weak position into a strong one. They "just know" what will turn the opponents weak position into a lost one.

And they remember. Every position in every game they have played and very many games others have played and analyzed openings too.

This is not to say that these fundamental "hardwired" skills are everything. But they form the basis on which everything else is built.
> 0 votes

---
Tags: talent
---


title: What’s my best move here?

text:
# Question
Title: What’s my best move here?
I ask regarding for this position below.

```
[Title "White to move"]
[fen "5r1r/1p6/p1p2p2/2P1bPpk/4R3/6PP/P2B2K1/3R4 w - - 0 1"]

```

# Answer
> 2 votes
If you put this position into an engine it shows that white has a forced mate in 2

```
[fen "5r1r/1p6/p1p2p2/2P1bPpk/4R3/6PP/P2B2K1/3R4 w - - 0 1"]

1. Rh4 gxh4 2. g4#

```

---
Tags: analysis
---


title: Overkilling the opponent

text:
# Question
Title: Overkilling the opponent
Every chess player has experienced this at least once in his life: An opponent who refuses to resign, even though being bare-kinged against a rook and 5 pawns...

Usually, kids are told to not be tempted and mate in the most efficient way (with the positive side effect that they're not encouraged to develop a personality that humiliates others).

However, playing on in a hopeless position is very provocative. It says "I think that there is a realistic chance that you do not manage to win despite this huge advantage!". They play on, hoping for some miracle (i.e. flag fall / stalemate).

**Is it wrong/bad etiquette to overkill the opponent, e.g. by making 5 new queens?**

Aren't they begging for the chances? The game will be at least a tiny bit more interesting for the winning side, as they need to be careful not to stalemate or let the flag fall.

Or is it cruel, arrogant and humiliating to do this to the opponent?

# Answer
> 13 votes
> Is it wrong/bad etiquette to overkill the opponent, e.g. by making 5 new queens?

Not only is it not wrong it may be the best course of action in that it may bring home to the opponent how bad their decision is to not resign.

About 15 years ago in a game against my club captain I tried doing this. He never resigned, was an almost constant opponent in our internal club competitions because we were similarly rated with me being about 100 points higher.

In the game I lined up 5 connected passed pawns and marched them up the board in line until they reached the 7th rank. Then I started promoting them. To my amazement he resigned after I made my third queen. "Why on earth did you resign?" I asked. "Because you have mate in 3" he replied.

I'm not sure I believed him but in any case the next time we played he resigned in a normal way.

Here is one of the Chessbrahs showing how it is done with 5 rooks.

Another good way of dealing with the very late resigner is to play on until you are only 1 or 2 moves away from checkmating. As long as you have plenty of time left on your clock go off and look at other games. Come back occasionally to look at the board and clock but don't sit down. If you get down to 2 minutes on the clock and still no resignation is forthcoming then finish your opponent off. This is only likely to happen if your opponent has no friends to come and look at the board and see their friend stubbornly sitting there refusing to resign.

# Answer
> 12 votes
IMHO, you should go for the kill in the most efficient way you could. If your opponent shows poor sportmanship, you show him the opposite.

# Answer
> 8 votes
Hold on -- you resent the opponent prolonging the game unnecessarily, so to get back at them you prolong the game unnecessarily? To put it bluntly, that is stupid behaviour. You are cutting off your nose to spite your face.

# Answer
> 7 votes
Overkill by your definition may be considered poor sportsmanship even though continuing to play in a losing position really is not. Resigning in such cases is a matter of respect, and it may be a matter of good gamesmanship if your opponent gets frustrated when you do not. After all, your opponent must prove they can beat you. It can be considered good play, particularly in speed chess, because at the very least you are looking for your opponent to make the wrong play and accidentally stalemate you.

Likewise, an opponent that is trying to "overkill" you by delaying the obvious win is actually playing poorly since they could accidentally stalemate you, run out of time because they are not paying attention or, horror of horrors, accidentally give you the advantage to give you the win.

So what may be a childish, teasing of your opponent is not really unethical since it's poor play that could cost them. Your opponent thinks they are humiliating you but you *want* them to play this way if you are in that situation.

# Answer
> 6 votes
First, let's look at reasons why your opponent might not resign:

1. They might want to see how you checkmate them. In that case, going for the most efficient checkmate you can find will do both of you a service. Newbies generally don't know basic mating patterns and even when they get an overwhelming material advantage, they don't know what to do with it, so they end up flailing around giving check, hoping eventually it will be mate.
2. They are hoping you will stalemate them. Going for 5 queens is a good way to wind up doing it!
3. They simply don't know it's good etiquette. Newbies may have the mistaken impression that resigning is poor sportsmanship, akin to taking your ball and going home or ragequitting in a video game.
4. They were taught (perhaps by Ben Finegold) to never resign. I think that's a good enough rule for someone just starting out, but afterward it can be refined thus: resign when and only when neither player has anything left to learn from the game.

So rather than going for 5 queens, I think it would be better to address the reason why your opponent isn't resigning. But if they don't have a reason and still won't resign, by all means go for 5 queens if that's what pleases you.

# Answer
> 1 votes
There are several different angles to this:

1. Yes, it is bad manners to not give up a really hopeless position. On the other hand it is even worse manners to point out the bad manners of the opponent, even if justifiedly so.
2. Every opponent is allowed to play as long as he has time and moves - these are the rules. Yes, there are hopeless positions but there are also players who hopelessly overestimate their position. I once had an opponent (casual game) who would tell me to "please give up a hopeless position" (he was up an exchange in an endgame) until I got his rook with a fork, which I forced him into with a series of threats. Funny enough he played on until mate. Needless to say I refused play him since then - some opponents are beneath me - but I refrained from saying anything during the game. Bottom line: yes, it might be quite tedious to win a won game - but bear your fate with dignity! After all, *your* manners at the board are better than your (ill-mannered) opponents, aren't they?
3. Take it as an opportunity. I sometimes - especially in online blitz - take such people as opprtunity to practice mating with knight and bishop. There is a rare chance that this endgame comes to pass naturally and hence, if possible, I promote to a knight and a bishop, sacrifice everything else and mate with knight and bishop. It is a pleasing sight to see these two pieces working together and it is also a lesson for the stubborn opponent that he is mated in the longest, most complicated and still inevitable way.

# Answer
> 0 votes
If you were teaching the opponent and the time spent was an exercise in more than chess, then more than 2 goals are actually simultaneously accomplished.

# Answer
> 0 votes
Kind of a tangential response, but when this situation occurs over the board I have an alternative to the normal overkill. I do this when

* **The position on the board is dead lost** for my opponent. This depends on playing strength, but I mean a position that's completely and utterly hopeless, not just a big advantage - *unlosable* is the term.
* **I have plenty of time on the clock** to win at leisure.
* **My opponent *should* know how bad the situation is** for them. Sometimes with beginners they might not be certain exactly how lost they are, even if they know I've got a big advantage, or they're still at a level where they might be taught never to resign.

When all of this is true, I like to ask my opponent *(in a friendly way)* "what, you don't think I can win this?"

A lot of the time, this will result in them acknowledging that they're grasping at straws: "yeah, haha, you never know". Sometimes they resign afterwards sheepishly, sometimes they play on in which case I often say "yeah, that's fair" and then do my best to win as efficiently as I know how to - they didn't mean anything bad by not resigning, no harm no foul. If they take this poorly and say something like "make your move" angrily, then I'll consider taking them on a trip down victory lane; if they want to be stubborn, I'll get my money's worth.

The only other response I've gotten to asking this is a few times opponents have told me I wasn't supposed to talk to them during play, at which point I shut up and mated them uneventfully. Valid response, I suppose.

---
Tags: etiquette
---


# Question
Title: How would this position be scored if you ran out of time here?
Here is the position (black has just played Qf8, the only legal move after White's Re8+):

```
[FEN "2nKRq1k/6pp/8/3n4/6b1/8/8/8 w - - 0 1"]

```

In this position white has a forced mate in one, in the most literal sense. If white lost on time here, how would this be scored? Running out of time usually means losing the game. However, I think this would be considered at least a draw since black cannot checkmate white by any sequence of legal moves. I am wondering if there's anything in the FIDE rulebook that says something about such 'literally forced mate' positions, or how an arbiter would handle a position like this in real life, since just a draw for white does seem a bit unfair to me.

# Answer
> 3 votes
You already answered it yourself - yes, there are §§§ relating to this. Let's check the rule book:

§6.9 Except where one of Articles 5.1.1, 5.1.2, 5.2.1, 5.2.2, 5.2.3 applies, if a player does not complete the prescribed number of moves in the allotted time, the game is lost by that player. \[*These §§§ do not apply here.*\] *However*, the game is drawn if the position is such that the opponent cannot checkmate the player’s king by any possible series of legal moves.

And indeed, the only possible future is Rxf8#. That's not the player's king, draw.

Since I strongly suspect a duplicate, I use the space to a comment on "unfair". Other rules *have* been tried, especially in blitz (specifying concrete material etc., e.g. B vs. N is lost for any side getting flagged, although a helpmate seems preposterous). But this is the only rule that is short and easily checked.

---
Tags: rules, fide, draw, time-control, forced-move
---


title: Karpov-Kasparov matches prearranged?

text:
# Question
Title: Karpov-Kasparov matches prearranged?
In an interview toward the end of his life, among other (questionable) things, Fischer claimed that the Karpov-Kasparov matches were prearranged.

Is there any evidence to support this idea or was it likely another of Fischer's delusional conspiracies?

# Answer
> 7 votes
**No evidence to support this**

It's hard to prove a negative, but I've seen a lot of coverage of Karpov-Kasparov and none of them even hinted that the matches were pre-arranged. Fischer is the only person who thought that way. Most other people loved the high-quality chess the matches produced (example).

# Answer
> 0 votes
Close to Fischer's death he had a somewhat candid interview with someone. I can't remember sorry. If my memory serves me he was giving the interview on the plane to Iceland. The interviewer asked his opinion about certain chess players.

Kasparov was the only one that Fischer respected. When asked about Garry he gave an answer with very strong body language that Kasparov was strong in his opinion. Its possible Bobby was just mouthing off about the matches or mouthing off at the Soviets.

I'm kinda like that myself with Communists or any aggressive form of governance. I tend to think of powerful party members more akin to the mob that would not hesitate to fix the matches if it would make them money and I think Bobby was just pulling everyone's leg. The interview was on YouTube as late as 2013. It might be archived by now. If Bobby really thought the matches were fixed I doubt he would have a good opinion about Garry's chess. This would be akin to Fisher ranting about Jews when he knew full well since early memory he was a full Euro-Jewish descendant.

I hope that the YouTube video is still there because it is worth watching and Fisher was very normal behaving and polite enough not a ranting madman. The beard he wore might make some think so but I digress.

---
Tags: fischer, kasparov, karpov
---


# Question
Title: How do I play against the Queen's Gambit Declined Tartakower structure?
I play the Exchange Variation against the QGD, but I'm really struggling against the Tartakower style setup in the QGD, when black plays b6 and c5. As White, I just don't really know what I'm supposed to be doing against this setup. In the normal Carlsbad structure of the Exchange QGD, I play for f3 and e4 or a minority attack but neither seems to work in these Tartakower structures.

Here's a position that I've reached several times:

```
r2q1rk1/pb1nbpp1/1p3n1p/2pp4/3P3B/2NBP3/PPQ1NPPP/R4RK1 w - c6 0 12

```

Do I play on the queenside? It seems pretty difficult since black frequently plays c4, a6, b5, and is better on the queenside. Do I play in the center? This just seems impossible. I don't really see how I'm supposed to do anything on the kingside either, since pushing pawns would only expose my king. Taking on c5 doesn't seem to help since after black recaptures with bxc5, I still don't know what I should be doing.

Here's an excerpt from a game of mine (opponent and I both about 1900 FIDE) arising from an 3...a6 QGD:

```
r3r1k1/1b1n1ppp/pp1q1n2/2pp4/3P4/2NBPN1P/PPQ2PP1/R2R2K1 w - c6 0 14

1.Bf5 c4 2.a4 Rac8 3.Ne5 g6 4.Bxd7 Nxd7 5.Nxd7 Qxd7

```

At the final position in the diagram, I feel like I've already messed up. Black has a space advantage on the queenside, attacking prospects on the kingside with g5, g4, rook lift to h6, etc. I reached this position thinking it was okay because of Black's "bad" bishop, but the bishop can just be rerouted to f5 and be situated on an excellent diagonal.

What are some of the plans/strategies that White has in these types of positions?

# Answer
The position you give looks like you have developed your pieces to suit the Carlsbad pawn structure where black has pawns on b7 and c6 instead of b6 and c5. So, the first thing to say is that you probably need to be less formulaic in your opening moves. You need to react to how your opponent is developing their pieces and place your pieces accordingly.

For instance, in this pawn structure the knight belongs on f3 not e2. As you say, the plan f3, e4 doesn't look so good now. The queen also doesn't belong on c2.

Your opponent gave you clues by playing b6 instead of c6. You needed to adjust your play at that point. Maybe Nbd7 instead of c6 was also an early clue.

In general in this kind of position you cannot let your opponent play c4 and b5. Life will become very difficult if you do. You need to take immediate action and transform the pawn structure with dxc5 and play against the resulting "hanging pawns". Follow up with b3 to stop the hanging pawns from advancing. If either of them does then take and leave your opponent with an isolated pawn which you can target.

Meanwhile bring your rooks to the c and d files. Rearrange your minor pieces to attack the hanging pawns and prepare either e4 or b4 to break them up.

There is an excellent book by Ivan Sokolov called "Winning Chess Middlegames: An Essential Guide to Pawn Structures" which you would find very useful at your level. It has 4 chapters:

1. Doubled Pawns: 12 essential structures
2. Isolated Pawns: 10 essential structures
3. Hanging Pawns: 4 essential structures
4. Pawn Majority in the Centre: 7 essential structures

Chapter 3 will obviously have much useful material and advice but all 4 chapters are excellent.
> 3 votes

# Answer
You can also play to blockade the pawn duo as a whole preparing for either pawn push. The complex will get in the way of enemy pieces while you find safe havens for minor pieces backed by rooks. It may only be practical or possible to blockade the helper pawn. The other will find itself restrained by its partner's inability to aid its advance or become an easy target. Once the structure is firmly stopped then you can look for ways to roll it up or destroy it. The other gentleman's post gives good instructions.
> 0 votes

# Answer
In your first position the Ne2 seems misplaced. Not so much because of the pawn structure: it would make sense against hanging pawns if it could jump to f4 and pressure d5, it would also make sense with a closed center if it could sneak to the kingside via g3 and f5; but because it is coordinating badly with your Bh4: both 12.Nf4? and 12.Ng3 lose material to 12...g5.

In the same position with Nf3 instead of Ne2, White has much more pressure against the center (Black always has to reckon with a possible Ne5). In this game of mine, Black erred early (13...Nf8?) and lost material, but most other moves would also have been met by either 14.dc or 14.Ne5.

---

In the second position Black is already very fine: the exchange of the dark-squared bishops provided space for developing the queen and reduced pressure against their center. They also seem to have benefited from a few tempi in the process. Passive play like 1.b3 Rc8 2.Qb2 c4 3.bc dc 4.Be2 b5 is already dangerous: White probably never achieves e3-e4 and the Bb7 is very active.

Maybe there's a tactical bailout with 1.dc bc (1...Nc5 should be about equal) 2.e4!?, exploiting the Rd1-Qd6 vis-à-vis. 2...d4 3.Bc4 is a mess that must be checked carefully with ideas like 3...Be4 4.Bf7, 3...Ne4 4.Bf7 Kf7 5.Ne4, 3...Nb6 4.e5, 3...Qc6 4.Bd5 Nd5 5.Nd5 f5!? (otherwise 6.Rac1 trying to hold) 6.Nd4 cd4 7.Qc6 Bc6 8.Nc7 Be4/fe4 9.Na8 Ra8 10.Rd4 with an endgame that is certainly a draw at high level, but only Black can hope for more. 3...Rac8 also seems to keep White under pressure. Well, until further analysis thislooks dubious for WHite...

All in all, what you did in the game is not so bad: at the end, even 6.b4 (offering them a protected passed pawn) followed by 7.Qb2 and rook shuffling doesn't leave an easy plan for Black to make progress.
> 0 votes

---
Tags: strategy, positional-play, middlegame, queens-gambit-declined
---


# Question
Title: UCI engine command white giving the same move
I need help from someone who knows about UCI engines. I am giving the command by double clicking on stockfishengine.exe and manually entering commands. I wanted to play white and I am running arena to play as computer (black).

I entered the following pgns in sequence: e2e4, e7e5 (arena)... , e2e4

```
Commands entered:
uci
...
ucinewgame
...
position startpos
...
go infinite
...logs here...
stop
bestmove e2e4 ponder
------------
Arena GUI using stockfish engine made move : e7e5
------------
position startpos e2e4 e7e5
go infinite
...
logs here
...
stop
bestmove e2e4 ponder e7e5

```

As you can see above its still giving me e2e4 it should have suggested other moves for white instead of giving me the same best move. Can anyone help me on this? Thanks

Update:

Its still giving me the same best move. Maybe their are other things that I have to set before issuing position startpos ... command?

# Answer
> 3 votes
Follow my instructions in the screenshot.

# Answer
> 0 votes
You must send a new position to the engine after each move. There are two main ways to send the new position, which are to send a FEN, or to send the moves themselves.

1. `position fen rnbqkbnr/pppp1ppp/8/4p3/4P3/8/PPPP1PPP/RNBQKBNR b KQkq - 0 2`
2. `position startpos moves e2e4 e7e5`

---
Tags: analysis, engines, stockfish, uci
---


# Question
Title: What position has the most possible moves that all lead to being checkmated?
Inspired by this position from a game I played.

```
[FEN "r1b2rk1/p2p1p1p/2qb1PpQ/2p1p3/2p1P3/5N2/PPnP2PP/R1B2RK1 b - - 0 1"]

```

Black has almost all their pieces, is not in check, and can make 27 (by my count) moves. None of them can prevent mate next turn.

Let's take this further. What legal position has the most possible moves yet results in being mated next move?

# Answer
> 3 votes
I bid **200 moves**, with two moves added courtesy of an improvement by @James Martin.

```
R4Q2/2Q4Q/4Q3/1Q4QB/3Q3b/Q4R1q/2Q1rprN/2nbBKNk w - - 0 1

```

# Answer
> 2 votes
I only write this as an answer (it isn't) as this is an invaluable source for one-move records, with citations (surely more questions on CSE apply). Since the positions are rather old some records might be broken (or will be broken by Rewan after he fought through the linked site's Excel table).

Sorry, German only

According to the table (if I interpret the terminology correctly) this would be "erzwungene Mattduldungen". You can search this simply in the SCHWALBE PDB by entering this term as STIP= search. Since even "voluntary" instead of "forced" gives only a record of 201 (P1179075) under this side condition ("With promoted material, legal" - seven subtypes are listed), I guess Rewan's record stands. Allowing illegal positions, 255 (P0005619). Forbidding promoted pieces, 135 (P1178928). Since this peculiar record is missing, I suggest Rewan updates the PDB.

(off to alert MatPlusForum)

---
Tags: problems, records
---


title: Chess Atomic Openings

text:
# Question
Title: Chess Atomic Openings
I'm studying Atomic Chess. Where can I find openings at? I've found the site Vlasov's Atomic-Chess Homepage so far.

# Answer
> 1 votes
You could explore the lichess database of atomic chess games here: https://lichess.org/analysis/atomic

It can be filtered by time control and player’s rating, shows numbers of games played and result percentages per position, and enables an analysis with a stockfish-variant engine.

Lichess is free and open-source.

---
Tags: opening, learning, chess-variants, atomic-chess
---


# Question
Title: Is this position winnable for white if black just shuffles?
```
[FEN "rnbqkbnr/p7/Pp1p1p1p/1PpPpPpP/2P1P1P1/8/8/RNBQKBNR w KQkq - 0 1"]

```

If black were to just shuffle the rook between h8 and h7 until white makes a capture or puts a piece on a square defended by a pawn, can white win (assuming black plays the all best moves after white tries something)? The only way white can win is by sacrificing material, but on the other hand white does have a large spatial advantage and can make any setup they want.

The first case I'm wondering about is if white knows black's plan to just shuffle until white tries something. I feel like this case is probably winnable. The other case is if white just plays 'optimal' moves and assumes black will too, which is probably a draw.

# Answer
> 1 votes
By shuffling black rook between h7 and h8 white can make it to this setup (or probably something similar) focusing forces on g5, and it seems Stockfish likes white's position (SF-16 +1.18 at ply 18) based on sacrificing a knight on g5.

The line provided by SF is: depth 24 \[+1.18\] 15.Nfxg5 fxg5 16.Nxg5 hxg5 17.Bxg5 Be7 18.Be3 Kd7 19.Ke1 Kc7 20.h6 Nd7 21.g5 Ndf6

# Answer
> 1 votes
White has a few ways to win if Black shuffles. Sac on e5 example:

```
[FEN "rnbqkbnr/p7/Pp1p1p1p/1PpPpPpP/2P1P1P1/8/8/RNBQKBNR w KQkq - 0 1"]

1.Nf3 Rh7 2.Bg2 Rh8 3.Nbd2 Rh7 4.Nf1 Rh8 5.Ng3 Rh7 6.Ne2 Rh8 7.Bb2 Rh7 8.Nc1 Rh8 9.Nd3 Rh7 10.Bc3 Rh8 11.Qc2 Rh7 12.Qb2 Rh8 13.O-O-O Rh7 14.Rhe1 Rh8 15.Nfxe5 fxe5 16.Nxe5 dxe5 17.Bxe5 Rh7 18.Bc3 Bd6 19.e5 Kf8 20.exd6 Nd7 21.Re6 Bxa6 22.Rde1 Bb7 23.Rg6 a6 24.Bg7+ Kf7 25.f6 Qe8 26.Re7+ Nxe7 27.fxe7 Qg8 28.Bc3 Rf8 29.Qe2 Ke8 30.exf8=Q+ Kxf8 31.Rxg8+ Kxg8 32.Be4 Rg7 33.Bg6 Rxg6 34.Qe8+ Nf8 35.hxg6 Bxd5 36.cxd5 axb5 37.Qf7# 1-0

```

I don't see how White wins if Black defends. If White tries to take advantage of space by alternating between different sacrificial squares Black can respond in time or walk their King away.

---
Tags: positional-play, closed-position
---


# Question
Title: Where to find the game "Brauner-Sollig Hildesheim 2001"
In a lesson from learningchess.net they presented this game. The blunder is so big that I wanted to check more about this game, but I cannot find anything online.

> Brauner-Sollig Hildesheim 2001

# Answer
> 2 votes
I wouldn't call that a famous game. It's actually a trappy line of the Petroff defense.

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

1. e4 e5 2. Nf3 Nf6 3. Nxe5 Nxe4 4. Qe2 Nf6?? {Qe7 is correct here} 5. Nc6+ {Regardless of how they block the check, black loses their queen for the knight}

```

---
Tags: famous-games, blunder, identify-this
---


# Question
Title: Why is coffee provided during big chess events when it contains a banned substance?
Why is coffee provided for free during big chess events like the Olympiad despite the fact that it contains caffeine, which is a banned substance according to the World Anti Doping Agency (WADA)?

# Answer
According to FIDE's Anti-Doping Policy:

> The 2018 WADA Prohibited List and Monitoring Program can be found at: http://list.wada-ama.org/ The most relevant banned substances for chess are:
>
> • Amphetamines – e.g. Adderall, Ritalin
> • Ephedrine and Methylephedrine – Prohibited by WADA when its concentration in urine is greater than 10 micrograms per milliliter
> • Pseudoephedrine is prohibited when its concentration in urine is greater than 150 micrograms per milliliter
> • Modafinil
>
> Substances not present on the Prohibited List but represented in the Monitoring Program:
>
> • Caffeine – Included in WADA Monitoring Program and relevant for incompetition testing only. Any urine test reading of less than 12 micrograms per milliliter poses no problem.
> • Codeine – A common ingredient in, for example, preparations used to treat coughs and stomach upsets. Any dosage is highly unlikely to be significant when taken in normal therapeutic quantities.

Note that caffeine is not currently banned. It was banned during the period 1984 - 2004 but was lifted. I'm guessing that sponsorship via advertising from Coca Cola may have been an important factor.
> 49 votes

# Answer
It is not prohibited would be the main answer.

Caffeine was removed from the list, and moved to the WADA "watch list", so it is not currently banned. "Bupropion, caffeine, nicotine, phenylephrine, phenylpropanolamine, pipradrol, and synephrine: These substances are included in the 2019 Monitoring Program, and are not considered Prohibited Substances." (quote taken from both the 2019 and 2020 WADA prohibited list PDF document).

"The legal limit under previous restrictions was 12 microgram/ml in urine, which is roughly equivalent to drinking 8 servings of espressos over the course of a few hours." (quote taken from nationalcoffee.blog)
> 20 votes

# Answer
Because nobody seriously considers it an advantage in chess. The WADA applies to sport, where caffeine can improve performance because it's a stimulant, thus improving physical performance. In chess, however, physical performance is meaningless, and no one has ever performed a test that proves caffeine leads to better chess (as opposed to, say, faster times in a race). Indeed, since one of its side-effects is an increase in impulsiveness, it could very well prove a *detriment* to playing better chess.

I can see where it might yield a minor advantage in blitz, where fractions of a second in punching the clock would matter. But in normal tournaments, I'd wait until someone actually does some testing before worrying about *any* substance.

OK, from the comments I see I need to add some details (in no particular order):

Java language: was called Green or Oak for most of its development. Oak was already trademarked, so they couldn't use it. Kim Polese of Sun held a brainstorming session among the development team in which hundreds of names were tossed into the discussion (James Gosling said he thinks half the words in the dictionary were named at least once). No one has the definitive origin, everyone who was there tells a different story of how it started -- good luck separating truth from retcon on that. (In fact one origin story has the group handing off a set of names to Sun's Lawyers, and they picked the name. In any case, the relationship to coffee is barely mentioned in any of the stories.)

Blitz phase: standard FIDE time controls have a 30-second increment, hardly necessitating fast clock punches.

Caffeine on performance:

Can we agree to draw a line between "physical performance" and "endurance?" The former (in chess context) is a measure of the ability to rapidly and assuredly and firmly move pieces, press clock buttons, etc. The latter relates to continuous activity. I thought that distinction was obvious; equally obviously it wasn't, given some of the comments. Again, my bad.

Relative to endurance https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5752738/ is a paper that concludes, among other things, that while controlled caffeine dosages can have some effect, the dosage is idiosyncratic; pertinent quote from the abstract: "Contemporary evidence suggests current standardised guidelines are optimal for only a sub-set of the athlete population." They go on to say the effect depends upon many individual factors, which of course renders a one-size-fits-all test irrelevant. (It might be material here to note that the range they talk about as being effective equates to roughly 4-10 cups of coffee (3-9 cans of Red Bull) an hour before the game for a 100kg person. (The paper's highlighted range was 3-9mg/kg, rather an imprecise setting but there it is). Given, as I said, that caffeine is known to lead to impulsiveness, I think I'd be pleased that my opponent came to the board with, say, 8 cans in him. I'd probably pass him a couple more quite willingly.

To my mind that paper is pretty strong. Higher doses than optimum give no additional benefit, and optimum doses for an individual are unknowable without doing a workup on the individual, so precisely what benefit does the testing provide?

Of interest but perhaps limited relevance here is http://www.anusha.com/uscfdrug.htm (the USCF resolution on drug testing -- the tl;dr of it is "test if your national committees give you money, but stop thinking it's performance related, because it isn't")

We have a nebulous (extremely wide range) dosage that may cause endurance benefits in some people. Which, to me, condenses into "We can't take this seriously without a lot more research."

Caffeine is known to promote impulsive behavior, and risk-taking (a cambridge study links it with gambling addiction, brings a whole 'nother meaning to the phrase "coffeehouse chessplayer"). I'm not sure how you can translate that kind of effect into "improves chess play."

But OK, maybe "nobody cares" might have been a bit over the top. My bad. I originally wrote "nobody who's familiar with testing methods and caffeine" (which, BTW, includes WADA, who specifically do *not* include it on their prohibited list) but decided the generalized version would keep me from having to write a dissertation about it. Looks like I was wrong.

There are a lot of urban legends about caffeine and software (same with whisky, the phrase is "the Ballmer Peak" if you're interested). Doesn't make any of them true; a wise person views them all with skepticism.
> 10 votes

# Answer
Caffeine is not good for one's chess in any amount one would actually feel. Tt always hurt my chess. I used to go to a player's restaurant and he would pump coffee into me all I wanted and I paid. Now I'm sad to admit I have played on stronger stimulants in the past and got mixed results. If I took too much my chess was simply terrible. I was not impulsive at all. I would play too slowly analyzing. If the level was right and I was not tired it would have a positive effect on my game. The nature of those stimulants is rather transitory and one can never put their trust in such things to improve their average game. I see why the stronger ones are banned because some might get a performance boost, but it would only be a short-term kick more than anything. One thing about stimulants that are not caffeine at the right dose is one's concentration is drastically improved and one becomes more focused. It's why they give it to kids. Those that are on it shut up and maybe pay attention. Curse them for doing this to kids. Alekhine used to eat candy "A brain is not a brain without sugar." No doubt that is a better choice even if it only gives one a placebo effect.
> 1 votes

---
Tags: fide, chess-olympiad
---


# Question
Title: Are there any recent resources on the Keres Defense?
I am changing my Black repertoire, and became interested in the variation:

1. d4 e6
2. c4 Bb4+.

I wonder if there are any recent resources about this "Keres defense" to learn some plans and ideas.

# Answer
> 2 votes
You could enter the position into the free Lichess analysis board or another board of your choice to see what the engine recommends and also to see what top players played in the opening.

As for books, I believe this one to be good (it is called the Kangaroo defence here but it's the same opening).

It is expensive on the website I listed but you can probably find it cheaper elsewhere.

---
Tags: opening
---


# Question
Title: Nimzowitsch and the defensive theory of open lines
I have read from Nimzowitsch over and over again how one could use a file as the basis of a restraining operation. All those who know his work know what I speak of, but good players at all levels understand the principle. Even if a given player does not know how to describe the strategic and tactical theme quite as a scholar they use the idea in everyday play game after game.

As for myself, I understand the concept at least on an intellectual level. But the writer had another line in mind that serves the same purpose namely the diagonal. Instead of a rook taking up a post against an enemy mobile pawn roller whether it be a central majority or a majority on the flank. The most dangerous in the opening and middle game is the mobile center. It has a crushing effect if one has not had time to occupy the semi-open file with a rook against the candidate along with other moves aimed at retarding the dreaded expansion. Of course, this tactic works against any majority forming the basis of a blockade. Well, that's pretty easy to see if one sets up an example.

But how does one go about achieving a similar goal based on the bishop as the main actor(birth of the flank openings)is the bishop? Here is where I think the rubber starts to hit the road in chess understanding because I still can't put my finger on exactly what that means in terms of how the other pieces arrange themselves to cooperate with the restraining bishop but according to the author restriction is too passive by itself and must be combined with even the smallest amount of threat based on the given line. If it is a file then the aggressive action should stay local and centralized. But if one is restricting on the diagonal the action is on the opposite wing.

**My question is basically how do the other pieces and pawns cooperate with the bishop in the double duty of discouraging an enemy advance all the while menacing the enemy flank at the same time?**

The author only recommends that aggressive action must combine with the defense. But he gives me too much credit to just compare to the vertical line and come up with a correct idea of how that particular scenario is to be handled. We have a whole bunch of so-called hypermodern openings that guys use day in and and out. My intuition tells me if I am correct the flank openings are based on this germ cell idea of Nimzowitsch(or he first put it into intelligible writing), that most players like me find themselves at sea when playing a flank opening against good resistance.

I'm asking for one of you strong players who understands the concept could help me get it. And if the procedure is truly something one should understand it should help a lot of players out playing flank openings at the very least and against them.

# Answer
To understand this strategem, I advise you to study the other "hypermoderns", especially Reti and Breyer who popularized fianchetto. There is even a "model" game by Reti, who lets the opponent build an impressive center, pesters it with Bb2 and Qa1 and then tears it to pieces. Dug it up for you: https://www.chessgames.com/perl/chessgame?gid=1102103 Analyze it!
> 4 votes

---
Tags: strategy, positional-play, bishops, defense
---


title: Lucas Chess Issues with Chess Openings

text:
# Question
Title: Lucas Chess Issues with Chess Openings
I am using Lucas Chess but its opening lines don't display appropriately. Here the engine doesn't show opening lines automatically. What opening book can I use with engine for preparation of absolute opening? Or, are there any opening apps for practicing openings?

# Answer
> 2 votes
If you know what openings you want to play, you could input it into the free Lichess analysis board. This will allow you to see what the most optimal moves are and also see the common replies from top-level games. You can also continue playing from a given opening position against the engine for practice.

If you don't know what opening specifically you would like to play, I highly recommend this book to learn general opening skills.

---
Tags: opening, learning, software
---


# Question
Title: Can one make a deal with their opponent over what opening to play?
In official tournaments, are the two players allowed to talk (before or at the start) of a match to compromise on openings, eg.

If white is good at the Sicilian but bad at the Caro-Kann and black is good at the Caro-Kann but bad at the Sicilian; could the two compromise to alternate playing the Caro-Kann and the Sicilian, to balance things?

I understand why this might be frowned upon, but are there any official rules (in FIDE or elsewhere) that explicitly prohibit this?

# Answer
## For a general case of match-fixing:

According to FIDE,

Appendix I, A.8.i. The deliberate use of external assistance by one player to gain an advantage over the opponent (such as using a computer or another player). **Cheating also refers to the purposeful manipulation of chess competitions such as, but not limited to, sandbagging, match-fixing, rating fraud, and participation in fictitious competitions or games.**

FIDE Laws of Chess:

11.1 "The players shall take no action that will bring the game of chess into disrepute."

The arbiters are given the power to take the required action(s) if some players are found guilty of purposefully manipulating chess competitions for their advantage. For eg, in the World Blitz Championship 2023, the game between Nepo-Dubov from Round 11 was nullified because they were found guilty of a pre-arranged draw that is mentioned in Rule 12.9.5 "reducing the points scored in the game by the offending player."
> 0 votes

---
Tags: rules, fide, tournament, etiquette
---


# Question
Title: Online resource for estimating my elo rating using my games?
There are resourses that can estimate your elo rating such as this one. Usually I need to solve some puzzles and the system will give me an estimation of my elo rating. Here I have a different thought: Can an online resource estimate my elo rating based on the games that I play?

For example, if I can upload the recent 100 games that I played under some standard time control, will there be a way to estimate my elo based on how I play? It seems feasible to me but I am not sure if such resource exists.

# Answer
> 5 votes
> For example, if I can upload the recent 100 games that I played under some standard time control, will there be a way to estimate my elo based on how I play?

If, as part of that upload, you also supply the ratings of opponents in the same rating system (i.e. all FIDE or all lichess or all chess.com) for at least 5 of the games in which you score at least half a point, then yes. Of course the moves played would be irrelevant.

The point being that no rating system gives a measure of *absolute* playing strength. Every single rating system gives a measure of *relative* playing strength.

# Answer
> 1 votes
My suggestion would be to estimate your rating based on your ACPL (average centipawn loss). You should be able to find this by using Chess Compass and looking at the report tab. I would recommend analyzing only 10-20 games for the sake of saving your time, and also going to settings and changing lines to 1 and depth to 14.

After you have obtained your ACPL for every game, average all of your results to get a representative ACPL for all the games in your dataset. The next step is to use a formula to actually estimate your rating based on your ACPL. Despite various online searches, I could not find any information on the subject, so I decided to try making some myself. Note that I used a relatively small sample size in doing so (around 15 friends all within the ELO range 700-1900 and then some public info for several IMs and GMs).

Here are the results, but take these with a grain of salt:

Rating = 2500 - 16 * ACPL (for ACPL less than or equal to 120)

Rating = 2700 - 20 * ACPL (for ACPL less than or equal to 30)

Another concern with using purely just ACPL is that your ACPL will change based on who you are playing. For example, I would normally get an ACPL of 35 against a similar player. However, I could probably get that down to 20 by trying to play a specifically solid opening (like the London System), or possibly up to 50 by playing a very chaotic opening (like the King's Gambit).

Additionally, ACPL will change based on who you're playing against. If I were playing a 1000 rated player I would easily get a probably winning position, but more importantly a very playable one and thus have a lower ACPL. However, if I were to play Magnus Carlsen (or even worse, Stockfish), I would have a higher ACPL because I would get into a difficult and unplayable position and thus end up getting a higher ACPL.

To conclude, getting your rating based on some games is a huge pain and you should probably just play a few rated games on chess.com instead. Also, sorry for the really late answer.

---
Tags: elo, online
---


title: How can I draw this KPPP-KR endgame?

text:
# Question
Title: How can I draw this KPPP-KR endgame?
See *Three (3) Pawns and a King vs King and Rook*.

I consider it one of the most amazing chess endgame puzzles.

```
[Title "White to play and draw"]
[fen "8/2k5/2r5/8/4PPP1/5K2/8/8 w - - 0 1"]

```

Of course I tried to solve it myself... I tried different approaches. E.g., trying to promote the g pawn with the aid of my king. Unfortunately, I had little-to-no success.

So how must I act in order to draw the game (assuming black has perfect play, always makes best moves and does not accept my possible draw offer)? What is the proper analysis?

# Answer
The underlying principle is that two connected passed pawns on the 6th rank are worth a rook (provided the opponent's king and rook are not too close). So, your aim is to to try and get close to that.

It's going to take several moves and meantime black is going to be getting closer so you have to try and keep black's king as far away from the pawns for as long as possible. The black king isn't allowed to move into check so the pawns can be used to keep the king at bay.

So, which pawn move to start with?

1.g5 looks tempting. Start moving the pawn which is furthest from the king and rook. The problem with this is that it doesn't do anything to restrict the black king.

How about 1.f5? The problem with this is that it creates a hole on e5 which sooner or later is going to be occupied by the black king. It is maybe the worst way of starting.

That leaves 1.e5. This stops the black king's best move 1... Kd6 getting closer to the pawns. It is the best first move.

Now let's think about something rather paradoxical. How is the black rook going to stop the pawns once they get far enough up the board to threaten to queen? The first principle of rook and pawn endgames is that the rook belongs behind the pawn. Ideally for black the rook is going to be on the first rank attacking the pawns from behind.

Here's the paradox. White does not want to move the king up with the pawns! White is going to want the king on the 2nd rank to control the black rook's attempts to attack the pawns from behind. If white doesn't do this then the black king is going to be able to stop the pawns going further while the black rook drives the white king away and the king and rook can start taking pawns.

If white stops the black rook from getting behind the pawns then the black king can stop the pawns making further progress but not start taking them because they are too far forward. If the rook tries to take the back pawn on g4 then the white king can step up to f3 to protect the pawn but must be prepared to allow black to take the g4 pawn.

This is the key position:

```
[fen "8/2k5/2r5/8/4PPP1/5K2/8/8 w - - 0 1"]
[Startply "9"]

1. e5 Rc3+ 2. Kf2! {not falling into the trap} Kd7 3. f5 {keep the black king away as long as possible} Ke7 4. e6 {almost there} Kf6 5. Kg2 {keep calm, don't panic} Ke7! {Draw} (5...Kg5 6. Kf2 Kxg4?? (6...Rc4 7. Kf3 Rf4+ 8. Ke3 Rxg4 (8...Kxg4 9. e7) 9. e7) 7. e7 {run baby, run!})

```
> 3 votes

---
Tags: endgame, draw, rook-endgame
---


title: Cochrane Gambit book recommendations?

text:
# Question
Title: Cochrane Gambit book recommendations?
Are there any good books that explain how the Cochrane Gambit works from white's perspective?

# Answer
> 1 votes
If you look on youtube there are an number of videos by strong players e.g. Miodrag Perunovic is 50 mins long. It is probably worth a try in quick games if you are frustrated at the normal symmetrical Petrovs

# Answer
> 1 votes
This page from Michael Goeller at The Kenilworthian seems to offer a definitive guide. The printed books listed there which discuss the gambit from the white perspective are:

* *The Alterman Gambit Guide: White Gambits*, B. Alterman (contains 40 pages on the gambit)
* *A Startling Chess Opening Repetoire*, C. Baker (contains 16 pages on the gambit)

The Kenilworthian lists a few other books, most of which are either from non-GM authors or not from the white perspective. It also has a collection of web resources (some of which are no longer available, but you can use the Wayback Machine) and videos.

# Answer
> 0 votes
If you go to Amazon books, you will find several titles listed, but nothing by a recognised author, so buyer beware. The response from deva does look horribly Chat\_GPTish but it is uncanny that if any GM had written about the Cochrane it probably would be Gary Lane. However, his web site does not mention one.

---
Tags: gambits
---


# Question
Title: What are the best practices for measuring search and evaluation speed?
I understand that perft is the standard tool for measuring an engine's move generation speed. However, during a perft search you don't execute your search, move ordering or evaluation functions - you just generate all the legal moves up to a certain depth and make/unmake them on the board.

I have found perft tests very useful for optimizing my engine's move generation, but aside from some basic unit tests I don't have an equivalent framework for testing my search and evaluation.

Are there are similar tools, methods or best practices for testing and debugging these parts of the engine?

# Answer
> 3 votes
I've just recently started developing my own chess engine, so i am by no means an expert. But ill still share my thoughts.

I think you can't make a generalization about search speed, as each search engine utilizes different parameters for its evaluation, resulting in cutoffs in search performance. Additionally, certain engines incorporate extensions when they encounter a "good capture" or early exit conditions.

Most search engines provide an output in terms of nodes per second (nps) for measuring the combined speed of evaluation and search. Nevertheless, it's crucial to understand that the interpretation of this metric may differ across engines, as some may include Transposition Table Lookups and other edge cases in their nps calculation.

Another approach for measuring evaluation speed involves disregarding the search phase and focusing solely on static evaluations performed on predetermined board positions. However, this method can be challenging to interpret as well. This is because some engines employ a complex static evaluation process, which may take longer, while others opt for a simple static evaluation but rely on a complex move-ordering algorithms. Ultimately, it's difficult to determine which approach is more effective and thus difficult to say which is more important.

---
Tags: engines, programming
---


# Question
Title: For daily games, will the order of resignation affect the rating?
Say a player with a daily rating of 1500 is playing three daily games at chess.com. His opponents' ratings are 1300, 1500 and 1700 respectively. This player has losing positions in all three games but he can choose the order of resignation.

If this player's goal is to minimise his rating drop after these three games, does it matter which game he resigns first? If so, what is the optimal order of resignation?

For me, a practical scenario is that I am playing a daily game against an opponent whose rating is much lower than mine. I am having a hopeless position but am delaying my resignation as much as I can. My hope is to find a "best" day when my opponent's rating is the highest so I can minimize the rating drop after losing this game. Does this make sense?

# Answer
> 3 votes
For a simple Elo system, it looks like you get the highest ending rating if you resign against the lowest rated player first, which follows with the intuitive responses from the comments.

The best order is to resign in is 1300, 1500, 1700, which would yield a final rating of 1457.0785. The worst would be to resign in would by 1700, 1500, 1300, which would yield a final rating of 1456.0237.

One caveat is that the ratings are typically going to be rounded off between each round, and the errors that rounding introduce can cause some of the other orders to yield the same results, but there the conclusion still remains that it is best to resign against the lowest rated player first.

---

| Rating | Opponent | Expected Score | Post Loss Rating |
| --- | --- | --- | --- |
| 1500.0000 | 1300.0000 | 0.7597 | 1477.2076 |
| 1477.2076 | 1500.0000 | 0.4672 | 1463.1902 |
| 1463.1902 | 1700.0000 | 0.2037 | **1457.0785** |
|  |  |  |  |
| 1500.0000 | 1300.0000 | 0.7597 | 1477.2076 |
| 1477.2076 | 1700.0000 | 0.2171 | 1470.6938 |
| 1470.6938 | 1500.0000 | 0.4579 | **1456.9561** |
|  |  |  |  |
| 1500.0000 | 1500.0000 | 0.5000 | 1485.0000 |
| 1485.0000 | 1300.0000 | 0.7436 | 1462.6910 |
| 1462.6910 | 1700.0000 | 0.2033 | **1456.5933** |
|  |  |  |  |
| 1500.0000 | 1500.0000 | 0.5000 | 1485.0000 |
| 1485.0000 | 1700.0000 | 0.2248 | 1478.2546 |
| 1478.2546 | 1300.0000 | 0.7362 | 1456.1697 |
|  |  |  |  |
| 1500.0000 | 1700.0000 | 0.2403 | 1492.7924 |
| 1492.7924 | 1300.0000 | 0.7521 | 1470.2296 |
| 1470.2296 | 1500.0000 | 0.4573 | **1456.5118** |
|  |  |  |  |
| 1500.0000 | 1700.0000 | 0.2403 | 1492.7924 |
| 1492.7924 | 1500.0000 | 0.4896 | 1478.1035 |
| 1478.1035 | 1300.0000 | 0.7360 | **1456.0237** |

Expected Score = 1.0 / (1.0 + 10^((Rating - Opponent) / 400))

Actual Score = 0.0

New Score = Rating + kFactor * (ActualScore - ExpectedScore)

*Note: these scores are based on a simple Elo system, not the more complex Glicko system that Chess.com uses. Later, I might try to understand how those calculations work and adjust my answer.*

# Answer
> 0 votes
Chess.com follows the Glicko rating system. I'm considering your player has played enough games to have a "confidence" rating, i.e. you get +8/0/-8 for a W/D/L vs an opponent having +- 25 to yours.

For every 25, 50, 75... points difference your opponent has, the rating change will alter by 1. It forms an A.P.. You can use the formula: `Higher elo - lower elo >= 50n - 25` where `n` gets you the alter in a rating change.

**Against 1300**, the rating gap is 200 -\> n = 4 -\> They'll lose 8+4, i.e. **12 elo**.

**Against 1500**, the rating gap is 0 -\> n = 0 -\> They'll lose 8+0, i.e. **8 elo**.

And similarly, **against 1700** the rating gap is 200 -\> n = 4 -\> They'll lose 8-4, i.e. **4 elo**.

For your example, it will **not matter** in which order the player resigns. They'll have the same elo in all 3 cases. This can be easily checked by putting the elo in the above formula after each game for all 3 cases.

**Note: This is NOT how the actual Glicko Rating works. I've presented the things in a simple way of how elo works on chess.com(enough games played) for the readers to understand!**

---
Tags: rating, online, resigning
---


# Question
Title: Why is the rook worth 5 points while the bishop is only worth 3?
Why is the rook worth 5 points while the bishop is only worth 3? Rooks only move straight, but bishops only move diagonally. Is there something that makes moving straight advantageous to moving diagonally?

# Answer
> 16 votes
Have a look at the wikipedia article on relative chess piece values, it provides an extensive discussion on the matter.

To see how you can compare two given pieces, let's consider your bishop vs rook question at a basic level:

* A rook's movement is not restricted to a color, unlike the bishop's. This makes half of the board squares inaccessible to a bishop.
* Assuming an empty board, the rook can always see 14 other squares from any other square, whereas a bishop's scope of legal moves varies between 7 to 13 depending on the square, the latter only reached when the bishop is centralised, something the rook doesn't care about!
* A rook has an additional way of moving when it combines with the king to castle, the bishop doesn't.
* A king and rook are sufficient to checkmate, but bishop+king vs king is a draw, as unlike the rook, a bishop cannot cut-off the king's path as it can always escape via the opposite square color of the bishop. Additionally, this difference allows a rook to achieve stalemate setups that a bishop cannot, as the rook is able to continuously check the king no matter where it goes.
* When combined, a pair of rooks can create a battery along a file/row, but bishops can only create batteries with the queen, or other promoted bishops of same color but those are not always a given. But now we're getting into more advanced details, so let's stop here.

So you see the collection of these properties make it clear that in an individual comparison, a rook's worth ought to be more than the bishop's. Now try to perform similar comparisons between any other pair of pieces in order to convince yourself where their relative values stand. Remember that key basic properties are:

* **Type of movement both individually and combined**
* **mobility and range**
* **ability to deliver checkmate when combined with a king**
* **square dependence (such as color, and centrality dependence of bishops)**

# Answer
> 12 votes
You need to understand that the point system is only a rough guideline meant to assist you in evaluating positions or in deciding on potential exchanges. Many factors, particularly the pawn structure, influences how valuable pieces are. Rooks tend to be better in open positions with fewer pieces/pawns on the board, bishops can get hindered in closed positions by pawns of the same color ("bad bishop"), etc.

Despite of all this, the 5/3 values for rook/bishop (or the piece valuation system in general) is surprisingly reliable.

A rook is generally more valuable than a bishop because:

1. it can reach all squares of the board, while a bishop can stay only on squares of the same color
2. it can mate in KR vs K, while you cannot win KB vs K.
3. it covers more squares (can always move to 14 squares on an empty board independent on where it is placed, while with a bishop it can vary between 7 (corner) and 13 (center) squares)

The exact values "5" and "3" are basically found from experience and since there is a bit of a drawing margin in chess, the exact values don't really matter.

One notable and very common exception to the rule is found in many (beginner's) opening play where a bishop and knight can be exchanged for a rook + pawn on f2 or f7. In these cases almost always having two light pieces is better even though you exchange 6 pawn units for 6 pawn units.

# Answer
> 5 votes
I would like to add another example.

1. A rook can isolate a lonely king from a portion of the board by forming a barrier. A bishop cannot; for that same task you need 2 bishops. That means, roughly, 1R~2B
2. 2 rooks can form a barrier that blocks a knight. 2 bishops cannot; for that same task you need 3 bishops. In this other scenario we have, roughly, 2R~3B

Averaging 1. and 2., we see that the quotient R/B lies between 1.5 and 2. Which seems to be in accordance to the theoretical values R~5P vs B~3P.

# Answer
> 4 votes
The pawn point system is only a very rough guideline to judge a piece's value. In the beginning of the game (as long as there are no (half) open lines for the Rooks to operate), a Bishop might very well be more valuable than a Rook. The Rooks get better and better the less pieces there are on the board, because they are more mobile "in vacuum".

Not only can they potentionally reach all squares (while a Bishop can only access either black or white ones, which sucks for mating a King in the wrong corner), they are also less restricted by the board's borders: No matter where a Rook is placed on an empty board, it can ALWAYS move to 14 squares (7 on its line, 7 on its rank). A Bishop in a corner can only move to the 7 squares of the diagonal to the other corner. Even in the best case (when placed in one of the 4 center squares), they have access to at most 13 squares. Thus, it's usually a good idea to keep your Rooks around for a longer time than your Bishops.

# Answer
> 3 votes
The point values are based primarily on how many squares a piece can command. Not only can rooks command more squares on an open board, but they can cover both colors, while bishops are restricted to squares of their own color. one on the black squares and the other on the white squares. Incidentally, both pieces move "straight", only the rooks do so horizontally or vertically while the bishops move diagonally.

# Answer
> 2 votes
You ask a basic but significant question. The question can be answered in either of two ways.

On the one hand, chess masters have found, roughly, that trading

* a rook and a pawn for
* two minor pieces (bishops and/or knights)

tends (averaged over many games) to leave realistic winning chances on both sides; whereas trading

* a rook for
* two minor pieces and a pawn

seldom leaves realistic winning chances on *both* sides unless a tactical combination is in view. By assigning the rook a value of 5 and the bishop a value of 3, the masters have given us a handy metric that roughly reflects a master's experience in the matter.

On the other hand, a rook can reach all squares on the board whereas a bishop can reach only half. *A rook can easily hide from a bishop by the trivial expedient of occupying a square the bishop can never reach;* whereas a bishop cannot hide from a rook in this way.

The two perspectives mesh. Either or both explains the valuation.

(By way of analogy, consider that, in contract bridge, experience finds that an ace almost always takes a trick, a king usually takes one, a queen sometimes takes one, a jack can take one but usually doesn't, and a ten seldom takes one. This is not hard to understand, since the ace is the highest card, but the rough metric bridge masters have developed from experience is to value an ace at 4 points, a king at 3, a queen at 2 and a jack at 1.)

# Answer
> 2 votes
From playing chess variants, we know that for Cylindrical Chess the strength of Rook and Bishop are practically equal. In this variant, both pieces have the same board mobility.

So, the main reason for the diminished strength of the Bishop in Classical Chess is its restricted mobility on the board: On an empty board a rook can always reach 14 squares, while a Bishop can reach between 13 (placed in the centre) and 7 (placed in a corner) squares.

Other factors (like the "can-mate" property or the "king-restriction" property) may play a role, too, but they are not decisive.

# Answer
> 1 votes
Since Bishops only move diagonally, a Bishop can only go to a square of the same color as it started on. White Bishop can't go on black squares, and black Bishop can't go on white squares. However, one Rook has the possibility to access all squares on the chessboard. This is one reason why Rooks are worth more than Bishops.

Additionally, rooks can also control more of the board at once, especially on the edges. When in a corner, a Rook controls all the squares of a rank and a file. When a Bishop is in a corner, it's severely limited because its line of attack is only 7 squares diagonal.

# Answer
> 1 votes
Im a bit surprised that nobody yet has mentioned that if you still possess both bishops they can in combination cover squares of both color. One Bishop plugs the holes that the other Bishop leaves. This is why it is often considered advantageous to have "the bishop pair".

But a great deal depends on the scope that the pieces have in the particular position, especially if there are weak pawns that may come under attack, perhaps after initial manoeuvres. Also the mobility of the King, if you are in, or about to be in, an endgame. The king and a bishop can attack a pawn, and the rook cannot defend that pawn by itself. If the King joins the defense, perhaps the other bishop can chase it off.

Counting points is never more than a start. I always do it automatically when evaluating an exchange, but then the immediate question has to be, "in this particular position, are there circumstances that might outweigh that judgement?"

# Answer
> 1 votes
Ellie points out that a rook, wherever it is, sees more squares than a bishop can. The reason for this is the shape of the board: rook-lines run parallel to the board's edges. If the board was of squares but was diamond-shaped (with its edges parallel to bishop-lines), the tables would be turned. Rooks are at their full power only when centralised, and are less powerful if nearer an edge. But bishops would be at their full power no matter where they were (except that as always they are colour-bound).

# Answer
> 0 votes
Two rooks are even more powerful than two bishops if it came down to an endgame where one opponent has two rooks they could easily use them to Roll the rooks and keep forcing the enemy king back to the edge of the board and give checkmate all by themselves without even needing the help of the king to do it. Now two Bishops and King Vs a king it takes a bit of work to figure out the tricky way to mate the enemy king and it would require the help of your king as well. It is a way trickier checkmate pattern that takes precision to execute. While the rolling rooks can be taught in just a quick session the two Bishop mate takes a substantial more sophistication and a ton more practice to become more consistent at it. The same goes for Knight and Bishop whereas a Knight and rook often kill the enemy king on their own.

# Answer
> -1 votes
Rook is a higher piece value due to the Checkmate factor . A Rook & a King can Checkmate the Opponent's King but a Bishop cannot . The Rook occupies more Squares on a Chess Board than a Bishop does . Lets take an empty board & put the Rook on a1 Square and then the Bishop. The Rook has 14 Squares under its dominance and the Bishop occupies 7 . If it is put on a Central Square the Rook has still 14 and the Bishop has max 13 .

So you see that Rook is much more worthy than the Bishop . I am not comparing any position where the relative value may be higher or lower .

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Tags: rooks, pieces, bishops, point-value, minor-pieces
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