# Question
Title: Which titled players (IM or GM) have also been successful politicians?
Garry Kasparov has been an unsuccessful politician and there have been several successful politicians who have also been quite good chess players, but have any of them achieved the IM or GM title?

Some candidates who didn't quite make it -

1. Nathan Sharansky, who according to his Wikipedia page, was the champion of Donetsk at 15, and who beat Garry Kasparov in a simul in 1996 has never even had a rating. He was in the Israeli parliament and government in the late 90's, round about the time he beat Kasparov.
2. I was sure that I read somewhere that Kirsan Ilyumzhinov who, as well as being FIDE president was also president of the former Soviet republic of Kalmykia, was a master level chess player. According to his Wikipedia page he was champion of Kalmykia at the age of 14. But according to his FIDE rating profile he has only ever played in one FIDE rated blitz in 2012 where he scored 2.5/7 against opponents with an average rating of 1954 for a performance rating of 1852.
3. British member of parliament, Angela Eagle, was according to her Wikipedia page, British girls under 18 champion in 1976 but, again, she never got a FIDE rating let alone a title.

# Answer
> 16 votes
Dana Reizniece-Ozola holds the title of Woman Grandmaster (2001) and is a politician who served as Minister of Economics (2014–2016) and Minister of Finance (2016–2019) of the Republic of Latvia. In the Olympiad of 2016, she beat Hou Yifan.

Perhaps not a minister, but in chess he reached the absolute top: former World Champion Anatoly Karpov. He's member of the Russian parliament since 2005.

Another example is GM Viktorija Čmilytė. She was European women's champion in 2011 and a member of the Lithuanian parliament since 2015.

One more example is GM Loek Van Wely. He was rated among the world's top ten in 2001 with a rating of 2714. He's elected for the Dutch parliament in 2019, so it's still hard to say whether he's a successful or unsuccesful politician.

# Answer
> 3 votes
* Utut Adianto is a GM since 1986 and politician. He serves as the deputy speaker of the People's Representative Council since March 2018.
* Marmaduke Wyvill (1815-1896) would surely have been a titled player if FIDE titles had been awarded in the past. He was a Member of Parliament and a leading English chess master. He won a nice game against Adolf Anderssen (winner the same year of the "Immortal Game")

---
Tags: titles
---


# Question
Title: Get Fide-rated without revealing your birthday?
I noticed the Fide rating list is always published with the date of birth of the player. Is registering one's actual birthdate with Fide a requirement for a Fide rating? It is a major concern for me given the rise in cases of identity theft.

# Answer
> 7 votes
Yes it is.

Article 1.14 in Regulations for Registration & Licensing of Players (effective from July 1, 2015):

> All player's data are obligatory for online registration in FOA. For players registered by the National Rating Officers or the FIDE Rating Administrator, first name, last name, gender, date of birth, e-mail address and Federation are obligatory for a successful registration.

# Answer
> 4 votes
> I noticed the Fide rating list is always published with the date of birth of the player

That is not true. The full date of birth is now never published, although in the early noughties it was. Now just the year of birth is published.

Furthermore that is often also not published. When you register you can request that your year of birth is also not published. To verify you can go to the "Advanced Search" on the FIDE rating website and search for female players from various Arab countries. If you do that you will see that for some of the countries many of the women have blank for their year of birth.

Example: United Arab Emirates.

> Is registering one's actual birthdate with Fide a requirement for a Fide rating?

FIDE require that to allow them to differentiate between two players with the same name. It does happen occasionally and then date of birth is essential. They don't need to publish even your year of birth. Once registered your FIN is enough to identify you in the system, and you can request even that is not published.

> It is a major concern for me given the rise in cases of identity theft.

You are wrong to be concerned. Your full date of birth is never published, only the year, and you can request that not even that is published.

---
Tags: rating, fide
---


# Question
Title: How much FIDE rated chess was played in April 2020?
FIDE has just published the May 2020 rating list which brings the ratings up to date for games played in April. The rating file can be downloaded from the FIDE download page.

Many countries have locked down some time in April (due to the current pandemic) and chess is no longer played. Some countries haven't locked down and chess may still being played. How has this affected the numbers?

A short explanation of how FIDE counts games.

Suppose I have a rating and I play two games, one against Jim Unrated and one against Jane Rated and I draw both games.

In Jim Unrated's record his game against me will be recorded because if he has enough games and reached a high enough level then his game against me will be used to calculate his rating. Even if he didn't qualify yet it will still be recorded to be used to calculate his first rating sometime in the future.

In Jane Rated's record her game against me will, of course, be recorded. The result will be used to calculate her rating adjustment.

In my record the game against Jane will be recorded because that affects my rating but the one against Jim won't be. He is unrated so our game won't affect my rating.

So, between the three of us we played 2 games but that will be recorded as 3 "half games".

I have some statistical questions regarding these “half-games.”

1) How many half-games of standard time control were played in April?

2) How many half-games of rapid were played in April?

3) How many half-games of blitz were played in April?

4) How do these numbers compare to March?

Note that *some* chess was played in April. For instance the Nigerian national championships was played. It was a 10 player all-play-all which started on 30th March and finished on 3rd April.

Sweden is also a country where there has been no lockdown and (some) chess has continued. Here is an example of a tournament which is played over several months but in any case lasting more than 90 days (looks like a club tournament where one round is played per month, started in October 2019) Round 7 of Horndal KM 201920 played on 15th April.

# Answer
Fascinating question. I computed the stats for each individual file (Standard, Rapid and Blitz) downloaded from the FIDE download page.

I added up the number of games reported for each FIDE player for each control time and list.

## Standard Time Control

* **145,618** games played in and reported in the *April* list.
* Only **9,946** games played in standard time control and reported in the *May* list!

## Rapid

* **54,192** games played and reported in the *April* list.
* Only **1,446** games and reported in the *May* list!

## Blitz

* **24,514** games played and reported in the *April* list.
* only **1,005** games and reported in the *May* list!

---

Regarding games played in April 2020.

The round 7 of Horndal KM 201920 has indeed been played on 15th April. However, the Nigerian national championships were played in March. See the report of the Nigerian Chess Federation.
> 4 votes

# Answer
As I said in an earlier answer I've built a database with downloaded data from Olimpbase and FIDE to allow me to do data mining. To answer this question I downloaded the latest (May 1st) rating list and loaded the data into my database and ran a few queries.

These are the results I get for Sum(Games) for April and May for Standard, Rapid and Blitz:

April Standard: 164531
May Standard: 10295

April Rapid: 68490
May Rapid: 1550

April Blitz: 56683
May Blitz: 1341

Interesting to note the small differences between my figures and Kortchnoi's.

I download the XML format file from the section on the download page where it says:

> Download full list of players (not rated included) STD, RPD, BLZ combined TXT format (01 May 2020, Sz: 21.11 MB) | XML format (01 May 2020, Sz: 23.77 MB)

I suspect Kortchnoi is downloading the individual files from where it says:

> Download STANDARD rating list TXT format (01 May 2020, Sz: 7.92 MB) | XML format (01 May 2020, Sz: 8.55 MB)
>
> Download RAPID rating list TXT format (01 May 2020, Sz: 4.28 MB) | XML format (01 May 2020, Sz: 4.58 MB)
>
> Download BLITZ rating list TXT format (01 May 2020, Sz: 3.15 MB) | XML format (01 May 2020, Sz: 3.38 MB)

Before this I always thought the main difference between the data sets was that the full set I download and use also includes the FIDE online Arena players as well. It looks as if the individual files miss out on some of the data.

EDIT:

To explore how many of these tournaments that were reported in the May list were actually played at least partly in April I looked at the players in the May list who are recorded as having played some games. There were 181, which is too many to list but it is worth looking at their federations.

## Fed - Number of players with Games \> 0

ARM 1
CUB 1
HON 1
ISL 1
NCA 22
NGR 14
PER 33
POR 38
RUS 59
SWE 6
TUR 1
USA 1
VEN 3

These players played in tournaments in 6 countries which, not surprisingly, correspond to the federations with the most number of players in this list.

Here are the federations with links to the FIDE page for the FIDE tournaments for May for each federation together with a list of the blitz tournaments for that federation, again with links.

**Nicaragua**
1er Torneo Blitz Nicaragua 2020, played - 15/3, reported - 13/4

Note, there was a rapid III Torneo Academia de Ajedrez Julio Ramirez de Arellano 2020 which was played from 18th to 19th April and reported on 28/4

**Nigeria**
DR NIYI ORIOLOWO NATIONAL BLITZ CHESS CHAMPIONSHIP, played - 29/3, reported - 31/3 (impressively quick reporting by the Nigerians)

**Peru**
II IRT TORNEO BLITZ CLUB DE AJEDREZ WANKA 2020, played - 8/3, reported - 30/4 (taking "manyana" to South American extremes)

**Portugal** \- 5 tournaments all played on 8/3, reported - 21/4
CD Rapidas Jovens Porto 2019-20 - U10,
D Rapidas Jovens Porto 2019-20 - U12 U14,
CD Rapidas Jovens Porto 2019-20 - U16,
CD Rapidas Jovens Porto 2019-20 - U18 U20,
CD Rapidas Veteranos Porto 2019-20

**Russia**
CHESS PLAZA\_March Blitz, played - 9/3, reported - 3/4
Perm blitz 17-03-2020, played - 17/3, reported - 4/4
Initsiativa club march blitz, played - 29/3, reported - 8/4

**Sweden**
Kristianstad Pasksnabben 2020, played - 13/4, registered - 13/4

So, only one Swedish blitz tournament was actually played in April although a couple of tournaments were played close enough to the end of March to justify reporting in April. There was also one rapid I spotted in passing played in April in Nicaragua.

Looking at Sweden in general there looks to be lots of league chess still being played at standard time control. Interestingly there was one standard tournament played in April in Russia that I noticed - Bratsk championship 2020, 11 round standard time control.

It will be interesting to do a similar analysis on the 1st June to see if any other countries are joining Sweden, or even if Sweden continues.
> 3 votes

---
Tags: rating, fide, statistics
---


# Question
Title: How to start learning theory? (1850 Elo)
I have been playing online chess (lichess.org) for three years at the rate of a few hours a week and I recently reached the score of 1850 Elo points in bullet mode.

So I want to take more seriously chess and in particular to learn the theory. To tell you the truth, I've never done any tactical exercises, I don't know any openings or complex finals.

How do I go about it? I am not at all afraid to use books.

# Answer
Learning theory involves some memorization of moves, but it's also important to understand the core ideas behind the moves. With these ideas, you can figure out what to play in novel situations not covered by the theory you've studied (or if you end up in a position that you forget).

There are different ways to study using an opening book. If you have a program like Chessbase, you could input the moves given, and also annotate in what you think the main ideas are. A good chess book will also take the time to explicitly explain the main ideas; some don't, which will require you to think on your own why a move was given. If you don't have Chessbase, I suppose you could go through the moves on an actual board, and jot down your notes somewhere (like in Word or a notepad).

If you're trying to get better at a new opening though, I'd suggest playing something longer than bullet - try at least 5 0. You want time to think about the position and apply the ideas (and moves) you've learned.
> 3 votes

# Answer
The way I learned chess, was by playing over games from books by great players and going over the analysis they wrote between moves. I think I have over 500 chess books.

I played over all games of Kaprov, Fischer, Alekhine, Capablanca, Smyslov, tal, etc.. and tried to guess what the next move should be before looking at it.

For learning how to think in chess, I found the book "Think Like a Grandmaster" by Alexander Kotov really good and taught me how to organize my chess thoughts during games and most important, how to be efficient in doing it. Sometimes we get our chess analysis cluttered during the game, and find we are going over the same analysis over and over. I am sure we all done this. This book helps in teaching one how to think better during the game (i.e. organize our thought process).

You also need to learn good chess openings. Learn few lines well. No need to learn very many lines. Just make sure to get to middle game in at least equal position where one then is out of the book. Need also to learn basic end game techniques. I studied many books on end game. Rook ending, Pawn endings, and learn the basic basic patterns that can show up in end game.

But for me, the best way to get better in chess, was to go over the classic books written by the best players and read their own analysis of their games.

Fischer's my best 60 games, and Alekhine 3 book collection of "My Best Games of Chess" written by him, and "My Best Games" By Kaprov, are such examples.

This can be very time consuming also. So pick one player whose style you like, and try to study their games and do the analysis.

A good collection with good analysis is the the `chess informator` books. I have large collection of these books. Study the games of the players you like their styles from these books.

At the end of the day, nothing beats playing chess with player who are stronger than you. After the game, go over it and see what mistakes you did. This is how you learn also.

My best US rating was 2430 I think or around there, and my ELO is 2310 (FM). I stopped going after the IM title as I got burned from chess. I do not play active chess any more.

Just some thoughts. Hope they help.
> 3 votes

# Answer
Personally I suggest you My System by Aaron Nimzowitsch.

It is an old book but I think still valid and a must have for every chess player.
> 0 votes

---
Tags: learning, study
---


title: Chess Engine: Faster Move Generation

text:
# Question
Title: Chess Engine: Faster Move Generation
## Introduction

I'm in the process of rewriting my chess engine for better performance. I've started with the move generation function first. I've been looking at this person's article (Their Article) about generating moves quickly. At the bottom, they have their list of tips for better performance. They claim using these tips gives them about 100 million nodes per second from the starting position, while qperft (qperft download) does 190 million (qperft does 290 million on my pc). While the fastest I have gotten from my move generation function has been about 10 million nodes per second.

## QPerft Output on my PC

```
From the starting position.
Quick Perft by H.G. Muller
Perft mode: No hashing, bulk counting in horizon nodes

perft( 1)=           20 ( 0.000 sec)
perft( 2)=          400 ( 0.000 sec)
perft( 3)=         8902 ( 0.000 sec)
perft( 4)=       197281 ( 0.000 sec)
perft( 5)=      4865609 ( 0.016 sec)
perft( 6)=    119060324 ( 0.414 sec)

119060324 / 0.414 ~= 290 million

```

## The Tips

1. Use SIMD instructions to do bitwise operations on multiple bitboards at the same time.
2. Use Kogge-Stone Generators for calculating moves for multiple sliding pieces at the same time.
3. Use the o^(o-2r) trick for calculating moves for single sliding pieces.

## Problem

The problem I am having is I don't understand how to use these tips.

## Problems with Tip #1

Their main tip for performance gain is to use SIMD (Single Instruction Multiple Data) instructions to do operations on multiple bitboards at the same time. The problem is I don't see how these are useful for generating moves. This is an example of how I've been generating moves (rooks for example).

```
Bitboard rooks = turn ? pieces[WROOK] : pieces[BROOK];
Square from = 0, to = 0;

while (rooks != 0) {
    _BitScanForward64(&from, rooks);

    // GetRookMoves uses magic bitboards (a lookup table using the _pext_u64 instruction for speed).
    // As far as I am aware magic bitboards are faster than Kogge-Stone Generators.
    // & (empty | (turn ? bPieces : wPieces) is to only get the moves that are on empty squares or capture squares.
    Bitboard rookMoves = GetRookMoves(start, full) & (empty | (turn ? bPieces : wPieces));

    while (rookMoves != 0) {
        _BitScanForward64(&to, rookMoves);

        // I am using a 32-bit integer to store all the information about the move
        moves[moveCount++] = /* move information (rook, from, to, etc...) */;

        // This is ofc to remove the move we have just looked at
        rookMoves &= ~(ONE << to);
    }

    // This is ofc to remove the rook we have just looked at
    rooks &= ~(ONE << from)
}

```

I don't see where using SIMD instructions could help in this move generation function as I don't see any bitboard operations that can be done together. Am I missing some obvious way where using SIMD instructions would actually help or am I just doing the move generation wrong in the first place?

## Problems with Tip #2

Their isn't much of a problem with tip #2. I am just wondering if magic bitboards are actually faster or if Kogge-Stone Generators with SIMD instructions are somehow faster. Also, Kogge-Stone is for calculating the moves for multiple sliding pieces at a time for legal move generation (I think). However, I am doing pseudo legal move generation because I think it is faster and easier.

## Problems with Tip #3

The problem with tip #3 is the same as number 2. Isn't it faster to use magic bitboards?

# Answer
> 4 votes
Move generation has been tested to death in modern chess engines, and the current consensus is that the following two approaches are optimal for sliding pieces:

1. A lookup table indexed by PEXT of the relevant occupancies ("Fancy PEXT Bitboards")
2. A lookup table indexed by the higher order bits of the product of the Bitboard of relevant occupancies and a magic multiplier ("Magic Bitboards")

Option 1 is preferred on CPUs which have a fast hardware PEXT (i.e. Intel Haswell and newer, no AMD CPUs at the time of writing). Otherwise, Option 2 is preferred.

For example, stockfish offers bmi2 and popcnt builds: the former uses PEXT bitboards, the latter uses magic bitboards.

### Kogge-stone

The Kogge-stone fill algorithm doesn't tend to be used in top engines for the simple reason that it benchmarks as being worse than the alternatives. I can offer a few reasons as to why this might be the case, but it is more important to recognise the fact that it *is* the case:

* They require a ludicrous number of CPU instructions. Each ray that must be cast (of which there are four) requires 5 shifts, 5 bitwise '&'s, and 3 '|'s, while the lookup operations only require 3-5 instructions per slider.
* While Kogge-stone can in theory be vectorised, there tend to not be enough sliders on the board to take advantage of this. For example, there tend to only be 3 (or fewer) rook-like sliders on the board at any given time. This makes the parallelism not worth the speed tradeoff.

### Actually improving move generation

A few things to note based on your code:

* Use `x & (x - 1)` to clear the least significant bit: this is faster than `x &= ~(1 << from)`
* Don't recompute the mask at every iteration: do it before the generation loop instead
* Use magic bitboards or PEXT bitboards: this is faster than Kogge-stone
* Make sure that hot move generation functions (like `GetRookMoves`) are inlined.

---
Tags: engines, software, programming, performance
---


# Question
Title: Ideas in Sicilian Defense: Staunton-Cochrane Variation
I am a Scotch player and don't like playing against the Sicilian and have very bad record against it (5.5/24), my best only wins are when I played 2.b4 ( Wing Gambit) or 2.c4 (Staunton-Cochrane Variation). In the Staunton-Cochrane Variation I have a mixed record (4/11), so I have decided to make it my standard reply to c5. I have success especially in this line :

```
[FEN ""]
1.e4 c5 2.c4 Nc6 3.Nf3 g6 4.d4

```

But I not not sure of the ideas if black chooses not to play the above lines. **What are the overall ideas and theory associated with this system ?**

# Answer
When you push d4 early on, the general plan is to protect the d4-square and e4-pawn, while developing quickly. With your king out of the centre things tend to become easier, and you can focus on more long-term plans. Meanwhile, if Black clamps down on the d4-square with ...e5, then they have also weakened their d5-square. Here the plan is to capitalize on the d5-square (not necessarily with an immediate Nd5), and to play on the flanks (for example, with a3, Rb1, b4).

I'll outline some theory for the lines you mentioned in your comment. At the end of my answer I'll give what I think is a better way to play the e4+c4 system.

* 1.e4 c5 2.c4 Nc6 3.Nf3 e6 4.d4 (delaying d4 with 4.Nc3 and 5.Be2 is also possible) 4...cxd4 5.Nxd4 Nf6. After 6.Nc3 Bb4, your e4-pawn is under attack. It is best to defend it with your light-squared bishop, but right now Bd3 loses to ...Nxd4. So you should play 7.Nxc6, and now there are two main responses:

+ 7...bxc6 8.Bd3. Now Black may strike in the centre with ...e5 or ...d5 (before or after castling). For example, 8...e5 (8...d5 is met with 9.exd5 exd5 10.0-0) 9.0-0 0-0 doesn't give White any advantage, but the position is playable. A possible continuation is 10.Be3 Bxc3 (10...d6 could be met with 11.Qc1 followed by a3, since ...Bxc3 no longer gives you doubled pawns) 11.bxc3 d6 12.c5!?.
    + 7...dxc6 8.Qxd8+ Kxd8 9.e5! Ne4 (or 9...Nd7 10.Bf4, followed soon by 0-0-0) 10.a3 Bxc3+ 11.bxc3 may give White a pull. He has the two bishops, while Black's minor pieces aren't that good (for different reasons). Note that 11...Nxc3?! should be met with 12.a4, when White may meet ...b6 with Be3 and a5. He has enough compensation for the pawn to claim an edge.
* 1.e4 c5 2.c4 d6 3.Nc3 Nc6 4.Nf3 g6 (4...e5 looks good for Black). Here White should play 5.d4 cxd4 (or 5...Bg4 6.d5 Nd4 7.Be2) 6.Nxd4 Bg7 7.Be3, but now this transposes to a line in the accelerated dragon. The theory here is well developed, and I'm not sure if this is what you're interested in, considering with 2.c4 I assume you're trying to avoid Open Sicilian lines.
* 1.e4 c5 2.c4 Nc6 3.Nf3 e5 4.Nc3 d6. Here I don't like the immediate 5.Nd5, and instead 5.d3 looks better (followed by Be2, 0-0, etc). The problem though is that Black can push ...f5, whereas you can't push f4 since the knight is already committed to f3. This gives Black at least equality, and while the line is playable, it would be better if your knight was on e2. After castling you could try playing on the queenside with a3, Rb1, b4 (and Nd5 if the position calls for it), but Black's kingside play looks easier.

In my opinion, due to the possibility of Black playing ...e5, I think it's best not to play Nf3. Instead, a setup with Nc3, g3, Bg2, Nge2 looks stronger. Then, you may continue developing with 0-0, d3, Be3, Qd2, f4, etc. The d4-square will remain a hole for now, but in general your setup is pretty harmonious. In addition, you can play it against a variety of different systems Black has.

A good introduction for this opening on YouTube is a video on the Botvinnik-English system by the Melbourne Chess Club channel.
> 3 votes

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


title: Why are these moves recommended?

text:
# Question
Title: Why are these moves recommended?
I am playing chess on the chess.com app with the top three suggested moves:

I am an amateur. I get the basic idea that developing your knights is a common, good thing early in the game, but why is that specific pawn move a7-a6 recommended? The queen could take it, but it’s protected by the rook.

# Answer
> 13 votes
The point is that 4...Nc6 could be met with 5.Bb5, when the knight is pinned and it's likely White will exchange it off with Bxc6. Without the c6-knight, Black will lose some influence over the key d4- and e5-squares. Playing ...a6 before developing the knight aims to prevent this.

Of course there's a trade-off here, since Black is spending a tempo just to prevent a relatively innocuous exchange.

# Answer
> 5 votes
Things you should consider this early in the game before playing your next move:

1. Development of your pieces
2. Control Over center

If you do not know about these, try reading about it before you play your next game. You'll see improvement on your own.

If I were to show you a blunder-filled game from black (see below). You can clearly see few moves wrong from here and black is down on pieces as well as defense is broken. White is easily winning. But this is highly unrealistic TBH.

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

1. e4 e5 2. Nf3 d6 3. d4 exd4 4. Qxd4 Be7 5. Qa4 Nc6 6. Bb5 a6 7. Bxc6 bxc6 8. Qxc6 Qd7 9. Qxa8 (4. Qxd4 Na6 5. Bg5 Be7 6. Bxe7 Qxe7 7. Qxg7 )

```

But those recommended moves remove a lot of pressure of black and keep the balance of the game equal.
1. Evaluating a6:

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

1. e4 e5 2. Nf3 d6 3. d4 exd4 4. Qxd4 a6 5. Qa4 Bd7 (5. Bb5+ axb5) (5. Nc3)

```

You can see clearly Bb5 is not at all good for white now. `4. Qxd4 a6 5. Qa4 b5` make white underdeveloped as white has to save the queen from the pawn. Even after using Nc3, Na4 or Na5 are just loss of tempo for white i.e, bad moves. Although, white can recover from here but so can black improve himself here.
2. Evaluating Nc6

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

1. e4 e5 2. Nf3 d6 3. d4 exd4 4. Qxd4 Nc6

```

You can see here the queen is under attack and the knight at c6 is covering 4 different squares a5,b4, d4,e5 and also e7 is possible if needed. And this also stops direct check threats to the king (Honorable mentions here would be that black has now one free space to move the rook and he is one step closer to queen side castling).
3. Evaluating Nf6 :

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

1. e4 e5 2. Nf3 d6 3. d4 exd4 4. Qxd4 Nf6

```

Similar to Nc3 discussed previously, Nf6 strengthens control over center by putting pressure on pawn at e4, d5 and controls g4 and h5 for now. After Be7 black will be able to do king side castle. This also saves queen from being harassed by Bg5.

All in all these are actually the better moves you should play here. Because if you don't white can easily take a lead and even if you are able to save your pieces, white will easily be able to mess up your pawn structure. Thank you for reading.

# Answer
> 2 votes
They suggested you play a6 to prevent the white-squared bishop from playing to b5...which will be a bad start to the game.

---
Tags: analysis
---


# Question
Title: What is the origin, or a early appearance, of this famous chess tale?
There is a story I have found across the Internet of an endgame between two players, usually named as Capablanca versus an extraterrestrial of some sort. According to the Spanish chess Wikipedia, the story is used as a demonstration of the logic behind pawn promotion rules.

Whoever the players, and whatever the story’s circumstances, the fantasy game more or less goes as follows.

---

**The Tale**

Player B challenges Player A to a game of chess, which Player A agrees to. Player A plays as White, and Player B as Black. An endgame is reached is which Player A has a great material advantage. Seeing an easy win, they play Kc2, planning on playing Bd4#.

```
[FEN "8/P7/BB5P/8/5NN1/3K4/p6p/k7 w - - 0 1"]

1. Kc2

```

However, Player B, not properly knowing the rules of promotion somehow, sees a defense and plays 1... h1=K!. The point is that Bd4# will checkmate one king, but stalemate the other, drawing the game. Player A argues over the concept that a pawn can “promote to any piece,” but soon grudgingly agrees with Player B’s view of the rules.

Then Player A, after some thought, has an idea and takes advantage of Player B’s interpretation of the rules. Player A plays 2. a8=BK!, promoting a White pawn to a Black king. Player B obligingly plays Kb8, the only legal move with their newfound king. Player A then plays 3. h7 and 4. h8=Q###, checkmating all three kings at the same time, thus winning the game.

```
[FEN "k6Q/8/BB6/8/5NN1/8/p1K5/k6k w - - 0 1"]

```

---

However, the origin of this tale is unclear to me, as it is often given with no sources. Additionally, most sources are in Spanish (or at least the ones the feature Capablanca are), so that might be indicative of its history. So far, the earliest date I have traced it to on the web is 2007, and the earliest video is from 2009.

Given that Capablanca became well-known in 1901 at the least for his match against Juan Corzo, the story is at least from then, if not started later in his life, the story is over a century old then. It might also a retelling from the 19th century with his name attached to it, since numerous chess guides came without fully defined promotion rules and chess composers of the era took advantage of it to produce numerous joke problems.

Does anyone of the origin of this basic tale as I presented, ignoring the player names and story circumstances, or an early appearance of it at the least?

---

UPDATE #1: I found an even earlier mention circa 2004 from this chessgames.com thread. In the linked page, the chessgames user "Phony Benoni," in their 2006 reply to a 2004 comment, said that the tale in question is featured in the book **Chess To Enjoy by Andrew Soltis**, which was published in 1978. So this puts the tale back as least 42 years. Someone will need to check the book for the composer or other information though, as Phoni Benoni merely gives the source. This is a great lead, however. Also, in the page before, in the initial 2004 post by user metriktracer, another source given is vaguely sourced as one of Andre Soltis's Chess Life columns from quote "twenty years ago or so." That might be another sweetspot if to be located.

Another 2004 reference is an Australian forum, this time with Capablanca against the devil. Now GM George Koltanowski appears to be another suspect for the composer: his name is also mentioned in the above linked chessgames.com thread. According to a comment on a paywalled video that features the tale, "GM Koltanowski told a similar story in one of his books. The Kolty character is Jesse's \[the person who made the said paywalled video\] way of giving Koltanowski credit for the story idea and ending composition."

---

UPDATE #2: I contacted Siegfried Hornhecker, author of the ChessBase article linked in @Phishmaster’s answer, to see if he knew anything about the problem. He took another look at the original publication that he quoted story from. I was told that the Amatzia Avni 2017 article, from the Enlgish magazine CHESS lists **Chess To Enjoy by Andrew Soltis** as its source for the problem. With two different appearances of the book as the source, it seems that the book may very well be the source; all it needs is for someone to check the it to see what it says.

The earlier mentioned George is indeed a real person who composed many problems, with most being from the 60’s and 70’s. This still leaves him very much as a possible author. He also. has more credence that Yuri. Dorogov, I think. A scan of problems revealed this Rex Multplex problem, which is a fairy chess condition allowing for mate to multiple kings. The given source is a humor book he wrote called Chessnicdotes, which means that he had at least the mentality to be the author.

---

UPDATE #3: @user5713492’s answer has traced the tale even further to a column by Andrew Soltis in **Chess Life, 1972 issue**, 6 years earlier than his book. Many thanks once more!

This also lines up with what chessgames.com user metricktracer said in the aforementioned chessgames.com Andrew Soltis page, emphasis mine.

“Hey fellas. twenty years ago or so, in **his chess life column**, he showed a problem with a UFO theme, wherein the losing side (the aliens)not havinig been given the rules properly, promoted a pawn to a king in order to avoid mate, but the contactee was able to checkmate both kings with a single move. this was so clever I actually carried it around for a couple years in my pocket. anyone know of this old gem?” - metriktracer, 4/13/2004

There followed this comment to it that is an amusing, supposed origin story for how Solits got the tale himself.

“It was based on a real event. A teacher had mislead his student by not specifying which pieces a pawn could promote to. So during a practice game, the student attempted to promote his pawn to a king. When the master tried to correct the problem, the student rebuffed him and demanded that they finish the game with the new (or old, depending how you look at it) rules. So the teacher managed to checkmate both his student's kings at the same time. This amusing event later found itself into Soltis' hands apparently. I thought it was pretty cool too, although I don't think the game is in this db. It is probably too hard for the viewer to understand the idea of three kings on the board, although I could be wrong.” - Benjamin Lau, 4/13/20004

---

I’ve concluded that Yuri Dorogov is the composer after reading the sourced Andrew Soltis book; see my new answer for the deductive reasoning. Also, this problem has appeared on the Schwalbe Database in the meantime.

# Answer
> 5 votes
I first saw saw this problem in Chess Life from 1972, p. 308.

# Answer
> 10 votes
I found a few references, but the best one was this article on chessbase.com that seems to attribute it to Yuri Dorogov, who was born in in 1947.

From that article, it is still not 100% clear if Dorogov created the puzzle and story, or was just the name of the person the creator used in the story, but Dorogov is a real person. This is a quote from the article:

> Yuri Dorogov’s story mentioned in the Avni article is too funny to not retell quickly here. It's white to play and win.

Again, this could mean either his actual work, or the story about him.

It probably had nothing to do with Capablanca, and someone just changed it later to add the famous World Champion.

P.S. I am tending to lean now toward it being Dorogov's actual composition as I found references in Russian chess books to his other compositions. He is an FIDE FM of chess composition (search Jurij Dorogov). I found four of his other compositions dated from 1970-1977, thus, I would tend to think that this was also from that general time frame.

# Answer
> 3 votes
I finally got around to reading the book *Chess To Enjoy* by Andrew Soltis after I found that I could borrow it on the Internet Archive. The problem appears on page 207, and the last name "Dorogov" is mentioned, which means that the suspected composer Yuri Dorogov is named in the story attached to the problem, with the usual alien vs person situation.

On page 205, Soltis gives this joke problem by Vladimir Korolkov, before the tale.

```
[Title "Vladimir Korolkov, Shakhmaty v SSSR 1969, Mate In 3"]
[FEN "3r4/KP6/5p2/RR3P2/2Nk4/3p4/3P4/8 w - - 0 1"]

```

The joke is that after 1. Nd6, and 1... Ra1+ to prevent the mate, White plays 2. b8=K!, and White gives mate with either rook after Black takes either king.

Soltis wrote this about the problem: “But, like Sam Loyd, Korolkov always tries to dress up his problems, often with a story. Sometimes his end result isn’t a problem per se but a story-plus-diagram.” Then the story is given, after which. the problem this question about appears.

Soltis wrote this before the tale: “A colleague of Korolkov’s named Dorogov topped this with a tale of meeting a visitor from outer space one day during a Caucaus rainstorm.”

As far I can read this, is means that Yuri Dorogov is indeed the composer of the problem. Since he “topped” the problem, is indicates that, since Korolkov published his story in 1969, that Dorogov published his tale sometime between 1969 and 1972, which is when it appears in the *Chess Life Magazine* issue linked in @user5713492‘s answer.

It is a minor mystery why Soltis doesn’t give the authorship in his magazine column, but that is perhaps a mystery lost to time.

---

EDIT: I did some Googling of “Yuri Dorogov”, and went deep into the results and I have concrete evidence of Dorogov being the composer!

Firstly, the site www.newspapers.com gave this clipping from the June 12, 1976 issue *The Ottawa Journal*, which is from Canada.

At the end of the short story, the clipping reads “(Story by Yuri Dorogov, translated from Russian).” This is direct attribution to Dorogov.

Secondly, I found a Spanish article entitled “ El marciano ajedrecista episodio 2”-Los increíbles mates de Capablanca contra 9 y 10 Reyes”, which continues what seems to be an Internet tradition for websites using the Spanish language of sharing a game supposedly between Capablanca and a martian/alien.

In the “Notes” section, the author Marcelo Reides states that he finally found the author of the problem, having shared it in another article of his. He states: “Completando las notas de aquella publicación, pude hallar al autor del famoso primer problema. En el anexo “Revista Ajedrez” “El primer contacto con un extraterreste nov 1975” podrán ver el artículo con el relato y el problema del compositor ruso Yuri Dorogov. Debo agradecer a los amigos Diego Sumic y Hebert Perez García que me enviaron el artículo y la revista escaneados.”

Roughly transcribed by Google Translate, it says in English that the story was shared an article entitled "El primer contacto con un extraterreste” in the November, 1975 issue of *Revista Ajedrez*, and in the text the authorship is ascribed to Yuri Dorogov. A picture of the print is helpfully given that confirms it. “Por” means “By” in Spanish, and it says “Por Y. Dorogov” beneath the title, which is direct confirmation that he is the composer.

---

With a known Russian author named Yuri Dorogov and a probable timeframe for it being composed between 1969 and 1972, if not earlier, all that is needed now is to find the original source for the problem.

---
Tags: history, pawn-promotion, capablanca
---


title: Three Pieces in the Attack

text:
# Question
Title: Three Pieces in the Attack
As a kid, my coach, an International Master, was repeating "if you have three pieces or more in the attack you can sacrifice without thinking!"

However, don't take this rule too literally!

1. Chess is a **concrete game** and we should not follow a rule "without thinking". However, I believe that chess is guided by some rules and general principles.
2. We can redefine the rule of "Three Pieces in the Attack" as **"Play more aggressively in the attack"** in a context where the **number of pieces attacking exceeds the number of pieces defending**.

My question is: by searching on the Internet, I could see this rule from time to time but I could not find its origin. Who devised this rule? How old is it?

I found a cute example here to illustrate this rule. White plays and checkmates a strong GM!

```
[title "Juarez Flores, C - Lputian, S, Manilla 1990"]
[fen "r6r/p4ppp/2p1b3/4R3/1kpR1N2/6P1/P1P2P1P/2K5 w - - 0 1"]

1.

```

I cover the solution for those who want to search:

> 1. a3! Kxa3 (1...Kc3 2. Ne2#) (1...Ka4 2.Nxe6 fxe6 3.Rxc4+ Kxa3 4.Ra5#) 2.Nxe6 Kb4 (2...fxe6 3.Rxc4 c5 4.Re3 Ka2 5. Ra4#) 3.Rc5 fxe6 4.Rdxc4 Ka3 5.Ra5#

---

The **Greek Gift** is another illustration of this rule because the `Bd3`, the `Nf3` and the `Qd1` coordinate to attack (the `Bc1` and the `Rh1` can also join the party)

```
[title "Greco 1792"]
[fen "r1bq1rk1/ppppbppp/2n1p3/3nP3/3P3P/3B1N2/PPP2PP1/RNBQK2R w KQ - 1 1"]

1. Bxh7!  Kxh7 2.Ng5 Kg8 3.Qh5 Bxg5 4.hxg5 f5 5.g6+-

```

# Answer
Francesco di Castellvi vs Narciso Vinyoles

```
[Event "?"]
[Site "?"]
[Date "1475"]
[Round "?"]
[White "Don Francí de Castellví(mars aka love)"]
[Black "Narcís Vinyoles(venus aka glory)"]
[Result "white"]
[FEN "?"]
[Time "?"]
[TimeControl "?"]

1. e4 d5 2. exd5 Qd5 3. Nc3 Qd8 4. Bc4 Nf6 5. Nf3 Bg4 6. h3 Bf3 7. Qf3 e6 8. Qb7 Nbd7 9. Nb5 Rc8 10. Na7 Nb6 11. Nc8 Nc8 12. d4 Nd6 13. Bb5 Nb5 14. Qb5 Nd7 15. d5 exd5 16. Be3 Bd6 17. Rd1 Qf6 18. Rd5 Qg6 19. Bf4 Bf4 20. Qd7 Kf8 21. Qd8#

```

This is derived from the poem which you can read here. I found this while watching this youtube channel.

At move 19 here I can see the three piece attack you were talking about. Here the bishop gets sacrificed for getting a checkmate. This the oldest usage of it that you'll find where the rules followed are the same as today.

Closest thing i could find was this sentence:

> "3 Piece Rule Compiled by notyetagm --\*-- You need three pieces to checkmate the enemy king, one to sacrifice and two to deliver mate. Of course more is better. :-)"

**Rule:** one of a set of explicit or understood regulations or principles governing conduct or procedure within a particular area of activity. It should be absolute(a value or principle which is regarded as universally valid or which may be viewed without relation to other things)

But we know that it is possible to Checkmate your opponent using less than 3 pieces. Example:
For checkmate using single piece =\> Back rank checkmate or a smothered checkmate
For checkmate with 2 piece there is =\> classic queen rook checkmate or Diagonal checkmate,etc

Hence, it is not applicable everywhere and thus it isn't a rule (you shouldn't considered it either).
*"if you have three pieces or more in the attack you can sacrifice without thinking!"* But this is a line that works a lot of time. So the question arises what is this? It's just a **strategy** or if you wanna be specific its a attack strategy or even a checkmate strategy in cases.

You can even generalize this as "trade off when you have more number of attacking pieces that defending pieces". **It actually establishes the basics** of our chess today, that might not be fruitful in all the cases. **As there is one and only one goal in chess , that is to defeat your opponent and obtain a victory.** So, Apply it all you want but make sure to win. Or at least its application should be fruitful to you and not your opponent.

As to my final answer to you, it isn't a rule it's a strategy and like other strategy's there is a very strong likely hood that someone played it before it got recognized by some name. As to oldest usage its Mars vs Venus,1475 if you'll consider this. So, regarding who and when, it's something i feel that has evolved with time along with the modern chess.

Thank you!
> 3 votes

---
Tags: strategy, history, greek-gift
---


# Question
Title: How can I prevent checkmate in this position?
It is White's turn to move. How can White avoid a checkmate?

```
[FEN "8/1kpP2q1/1p2P1p1/1P3pP1/5p1K/5P2/6P1/R7 w - - 0 1"]

```

# Answer
> 56 votes
**Initial Analysis**

White is clearly in a dire situation, since Black is threatening mate in one on either h7 or h8 if White doesn't do anything. But the White king can't move nor can White get rid of any of the pawns that surround the king. White's rook, the only White piece, is too far away to do anything. The move 1. Ra8? to try and stop 1... Qh8# fails to 1... Qh7#. Promoting White's pawn with 1. d8=Q? also fails to 1... Qh7#. So what can White do now?

**Assessment Of Available Options**

In order to prevent Black from moving the Black queen, White must give a check to the Black king so that Black is legally obligated to move the king instead of the queen. However, what check is there for White to give? Ra7+ doesn't work because the Black king will just take it and White cannot stop both mating threats. It seems that White is totally losing.

**However!**

There is only one move that can save White, which often goes unseen by many first-time problem solvers: **underpromotion to a knight with check: 1. d8=N+!** After 1... Kb8 (not 1... Kc8?, as that allows 2. Ra8#), White can forcibly checkmate Black in 4 moves with a constant stream of checks as any non-checking move loses. Therefore, White is not losing as it seemed before!

```
[FEN "8/1kpP2q1/1p2P1p1/1P3pP1/5p1K/5P2/6P1/R7 w - - 0 1"]

1. d8=N+ Kb8 2. Nc6+ Kb7 3. Ra7+ Kc8 4. Ra8+ Kb7 5. Rb8#

```

It is important to note that while 2. Nf7 seems like an option to block the Black queen, it actually loses as Black can then play 2... Qxa1!, and it is checkmate on the next move with 3... Qh1# no matter what White plays.

# Answer
> 14 votes
1.d8=N+ is necessary to avoid losing, but it also gives White a forced win after 1...Kb8 (1...Kc8 runs into 2.Ra8#) 2.Nc6+ Kb7 (2...Kc8 3.Ra8+ transposes) 3.Ra7+ Kc8 4.Ra8+ Kb7 5.Rb8#.

# Answer
> 6 votes
This is actually a cool position. Although, not easy to see as first sight, white can execute an Arabian Checkmate. Like others mentioned, executing the move `d8=N+` is the only move that saves white from checkmate. This would force a check, but also allow white to win with a maximum of 4 moves proceeding an Arabian Checkmate.

# Answer
> 4 votes
It's an underpromotion problem, with promotion to a knight on d8 with check by 1.d8(N)+ to avoid checkmate by the black queen on the ensuing move on the "h" file. All ensuing white moves must be with check for the same reason. If 1..., Kc8 then 2. Ra8# is mate, so the king must go to b8 with 1..., Kb8 after which White can follow up with 2. Nc6+ Kb7 (or 2..., Kc8 3. Ra8+ Kb7 4. Rb8#) 3. Ra7+ Kc8 4. Ra8+ Kb7 5. Rb8#.

---
Tags: strategy, checkmate, problems
---


# Question
Title: Are there illustrative examples where a conventionally "bad bishop" leads its side to a win?
I was looking the Chess glossary and two words brought curiosity : **bad bishop** and **big pawn**. *Where the later being the condition that occurs when you have a bad bishop*. One thing i noticed was bad bishop was always defined on end game reference. I don't understand why? Can't you have bad bishop or a big pawn mid-game or relatively early game!(?)

Found these images for bad bishop and big pawn on Wikipedia:

Hence, I wanted to know if there were any games where big pawn leads a chess player to victory (When enemy has a good bishop) at an international stage? or rephrasing the above as "occurrences where bad bishop was more significant to victory than a good bishop?"

# Answer
My understanding is that we call a bad bishop a "big pawn" especially in the endgame to emphasize the fact that the bishop cannot be considered a full piece in these situations. It can't move much. It is very passive. Having such a bishop is a **long term** handicap.

You are right, these situations can also occur earlier in the game, but there is always a hope that a passive bishop can be traded or become more active when the position opens.

For instance, in the Dutch Stonewall, the `Bc8` is a bad bishop but you can try to trade it by playing `Bc8-d7-e8-h5` or via a6 in some cases. Having such a bishop earlier in the game is a handicap, but calling it "big pawn" would be too definitive, the bishop can live again!

**\*"Occurrences where bad bishop was more significant to victory than a good bishop?"**

In the early stages of the game this is very possible and I'm sure we could find examples in the Dutch Stonewall or in the French defense where the `Bc8` wins the game. In the endgame, I guess this will only happen if the opponent makes a mistake to turn a bad bishop into a winner.

Here follows an example, where the bishop in e6 is a "big pawn". White could have taken advantage of that and won the game. But in the end, after White's mistakes, the "bad" bishop wins the game!

```
[Title "Max Euwe vs Vera Menchik, Hastings 1930/31"]
[fen "6k1/1p3ppp/4b3/2Pp4/8/4P1P1/B4PPK/8 w - - 0 1"]

1.Kg1 Kf8 2.Kf1 Ke7 3.Ke2 Kf6 4.Kd3?! (4.Bb3!! {Dvoretsky} 4... Ke5 5. f4 Kf5 6. Bd1! {arriving just in time to cover the g4-square} d4 7.Bc2+! Kg4 8.exd4 Kxg3 9. Ke3 f5 10. Bd1 Bd5 11. Bf3+-) 4... Ke5 5.g4 g5! (5... Bxg4? 6.f4 Ke6 7. e4 Ke7 8. Bxd5+-) 6.g3 Bxg4 7.f4+ gxf4 8.gxf4+ Kf6 9.Bxd5 Bc8 10.Bf3? (10.e4!?) Ke7 11.Kc4 Kd8 12.Kd5 b6! 13.c6? (13.Bh5=) Kc7 14.Ke5 Be6 15.f5 Bb3 16.Kf6 b5 17.Kg7?? (17.e4!=) b4-+ 18.Kxh7 Bc2 19.Kg7 b3 20.Bd5 b2 21.Ba2 Kxc6 22.f6 Kd6 23.e4 Bxe4 24.Kxf7 Bd5+! {The "bad" bishop in action!) 25.Bxd5 b1=Q 26.Kg7 Qg1+ 27.Kf8 Kxd5 0-1

```
> 5 votes

---
Tags: bishops, bishop-endgame, bad-bishop
---


# Question
Title: Is it possible that a radically different but equally effective playstyle exists?
There seems to be an established "chess canon", whereby general principles exist for long term strategy in the game. There is a well-characterized set of openings, a small subset of which are even played, and even in middle to endgame one can identify named structures, attacking/defending pieces, point values, etc. High level players and chess engines will occasionally break "the rules" - but on a move-to-move basis, not consistently throughout an entire game. In others words, it seems like even though chess has room for a lot of creativity, that creativity lies within a well-established theory of what one might consider "basic technique".

I am thinking of a project involving training an AI to play chess, but with a loss function that discourages common moves for that position - i.e. a chess engine that performs incredibly well but as unlike a human as possible. But before I launch into training, I'm wondering if such a thing is even possible. Chess theory is great for teaching humans how to play, but is it possible that it is the *only* way to play chess at the level that top humans do? Are there any obstacles to the possibility of a completely different playstyle that would consistently break every rule in the book but still beat top players? Or does modern positional analysis rigorously rule out other strategies?

I'm a total amateur at chess, just a machine learning engineer with an interest in the game - so I apologize if this question is trivial.

# Answer
> 20 votes
It's definitely possible there are strategies we don't know about. However, training your engine to specifically play *contrary* to all we know isn't the way to get there. For example, what would you do if one of your pieces were threatened? Our current knowledge says to not give it up for no reason, so would your AI therefore decide to give it up (because it's technically mathematically possible there could be some hidden idea 30-40 moves down the road?). You'd do better with random moves.

A better way to unlock hidden strategies is through a more bottom up approach. For example, AlphaZero learned on its own (*without* human knowledge), just using the rules of the game to guide it. From this, we saw a new style of playing that was basically unknown. But trying to get this new style of playing wasn't the primary goal.

Basically, it's fine to disregard human knowledge, but it's not fine to actively train an AI to play opposite to this knowledge. Here you're just trading one well established knowledge base for a vastly poorer one.

# Answer
> 6 votes
In principle this is pretty easy. Get a database of 10 million human games, re-score the positions with a chess program (Lc0 or Stockfish), then train a Neural net to prioritize a combination of score and not picking the human selected move. Once you had the data, this could be done in a few weeks of GPU time, and should produce a computer that makes relatively weird moves, and could probably be super-human in strength.

# Answer
> 5 votes
> I am thinking of a project involving training an AI to play chess, but with a loss function that discourages common moves for that position - i.e. a chess engine that performs incredibly well but as unlike a human as possible.

Of course it would be possible to program an AI (or even an ordinary computer with no intelligence) to play the most unpopular moves for each position. However it would also be the single worst performing engine in the world. Complete beginners would love playing against it because they would win quite a few games.

If you stop and think about it for a few seconds you will realize that most of the time most of the people try and play the moves which give the best results. The more these moves become known the more they are played. The really bad moves that lead to quick losses tend to be played the least.

This conclusion requires knowledge of human nature and little or no chess knowledge.

# Answer
> 4 votes
# Yes

But only actual experimentation will tell us if AlphaZero has left a meaningful amount of the chess space unexplored. Chess, like all games, boils down to two fundamental components:

1. Explore the space of possible moves
2. Evaluate the "goodness" of each such move

AlphaZero uses a technique called Monte Carlo Tree Search to perform 1, and Deep Convolutional Neural Network to perform 2. And Bob's your uncle! Ok, that is a gross oversimplification, but let me explain briefly how each piece works.

# Search

Games have a set of states and a set of moves which transition between the states. Since they usually have a single start state, and for simplicity, we usually model this set of states as a tree (rather than a graph). "Looking ahead" just means traversing layers down the "game tree". For a game like chess, which a high branching factor, you end up with a tremendous number of states in only a few plies, so much work goes into avoiding as many state nodes as possible (by trying to identify obvious losers and bailing on that path or following strong paths preferentially). MCTS goes for depth over breadth by "playing out" a particular move very deeply into the game. Since there are a limited number of moves for which one can perform this computationally expensive operation, it does so for only a random subset of possible moves. However, the subset is not chosen with a *uniform distribution*. The moves which are explored can be weighted by any heuristic you like. More about that later.

# Evaluation

If you're looking at a winning state, it is easy to give an evaluation. If you're not looking at a winning state, you have to decide if it's "good" or "bad". This is where the neural network comes in. Right after you make a move, it's hard to tell whether the move had a positive or negative effect on your winning potential. But it's much easier to determine after the game is over. So when the game is complete, you now have a win/loss signal for all the board states in that game. This is now trivial training input for deciding whether each of those board states was "good" or "bad" for you, and you can backpropagate that signal through the neural network which gives you the "good/bad" signal for each board state. This is the "deep learning" portion of AlphaZero.

Because this is the stateful portion of AlphaZero, you could also say this is where the "knowledge" is, albeit in a rather abstract form which isn't really accessible to inspection or query.

# Bias

If we assume that AlphaZero starts out by making uniformly random choices during MCTS, then it is fair to say that it explores the chess space without any particular bias. The DCNN may inform the MCTS layer, causing it to follow "good" paths rather than "bad" ones, but from what I've read, it prefers to follow "unknown" paths rather than "known". Basically, AlphaZero uses every game to increase its knowledge about chess rather than just trying to win the current game. Because it focuses on covering the space rather than just greedily following the most promising path, it learns much more broadly than chess engines with a non-stateful search algorithm, which must use their search cycles as economically as possible.

For this reason, one should suspect that AlphaZero is not leaving a lot of promising paths out of its repertoire. And, as others have noted, it's style is already quite different from most grandmasters, and it continues to teach us new things. Even so, there are free parameters in the AlphaZero design, which you may tune to extract different outcomes.

# Strategy

If you were to create a "most alien AlphaZero", you could take the basic architecture, and then train it on human games. However, this training would build a secondary network called the Human Predictor. The goal of the HP network would simply be to predict the moves most likely to be played by a human for a particular board state.

Now, when you execute the MCTS phase, instead of preferring "moves I haven't explored before", you prefer "moves which humans wouldn't make", leaving all the rest the same as AlphaZero. This should basically implement what you are looking for. My guess is that the play will end up looking quite similar to AlphaZero in areas where AZ already plays in an alien style, and will be inferior to AZ in games where AZ overlaps more with "human style".

The reason should be obvious: AZ has no restrictions on the kinds of moves it makes. When it plays differently from humans, it isn't because it's *trying* to. It's because it found, through exhaustive trial and error, that those moves are *simply better*. And not just better against humans, either: better even against itself! It's possible that one could train AZ to beat humans even more efficiently by using the HP module described above to model the counter-moves that the opponent is likely to make during the MCTS phase. Such a modified AZ may find that "pure" AZ is overly conservative because it gives its human opponents too much credit.

It's also possible to train a "Stockfish killer" variant by simply using Stockfish itself to provide the counter-moves during the MCTS phase. You would need to do this strictly during the learning phase, because you wouldn't have the computes to do this during a live tourney, but effectively, the DCNN would learn to play exclusively against Stockfish, rather than AZ, and skip any counter-play that a different engine might provide. Then, during a tourney, the MCTS could revert to the standard algorithm, since the DCNN has already captured the essence of Stockfish and stuffed it in a bottle.

Anyway, sounds like a fun experiment. Good luck!

# Answer
> 3 votes
The question is, equally effective against whom? You are correct that there tend to be "optimal" or "near-optimal" moves when engines play against engines. And when grandmasters play in long time control games, their moves often resemble those of engines. But when playing against lower-rated humans, or even against GM's in fast time control, there is a lot more flexibility in play. It just isn't possible for a human brain to calculate every possible variation, and so you can "get away with" not always playing the technically best move.

So in general, you don't have to operate under the assumption that your opponent is a 3500-rated chess engine. Against a human, you can play in a variety of styles that assume they might miss something, causing you to gain an advantage. This can take many different forms:

* Offbeat openings: Avoiding their opening prep and playing something outside their comfort zone.
* Playing a "trap": Allowing the opponent an opportunity to grab material that ultimately leads to a loss or a much worse position.
* Time pressure: Refusing trades and keeping the position very complex to force them to calculate and burn their clock.
* Limiting their options: Playing attacking moves that require very precise calculation to defend against. If they slip up, the game is over.

---
Tags: engines, computer-chess, style
---


# Question
Title: How important is castling? How much is it worth?
Are there some statistical values for the worth of castling? Are there some numbers, for example in centipawn that can represent the value of castling?

# Answer
The answer is a round **no** (sadly, this answer is highly subjective).

The reason for this, however, it is not because castling is dependent on the position. The argument that castling cannot have a value because it can lead to getting mated or because it can lose you the game is essentially flawed since for this same logic a queen cannot have a value because saving a queen can also lead to get mated or lose you the game. My reasoning for this lies on the following statistic of utilization of squares by chess Grandmasters. It is quite obvious that using both white and black, Grandmasters tend to castle in almost every game: `g1` as white and `g8` as black have almost always a value greater than `1`, meaning that the king is usually tucked in the corner for safety. Thus I would say that castling is, in average, a borderline indispensable tool that ensures the king safety.

Protecting one's king and checkmating the opponent's is the objective of the game, meaning that there is no need to assign a numerical value to the king because losing it means that the game is lost. Similarly, taking away one's option to castle severely hinders the safety of the king and, as seen above, is used virtually in every game. Hence castling cannot have a numerical value assigned since virtually every strategy to defend one's king uses it.
> 3 votes

# Answer
Yes there are some numbers that can (sort of) represent the value of castling.

If you let Stockfish or any other strong engine analyze the starting position, it will generally come to the conclusion that White has roughly a +0.50 advantage. But if you use an opening book (1. Nf3 Nf6 2. Rg1 Ng8 3. Rh1 Nf6 4. Ng1 Ng8 5. Nc3 Nf6 6. Rb1 Ng8 7. Ra1 Nf6 8. Nb1 Ng8) which lets Black castle but not White, the advantage actually flips around, and the starting position advantages Black.

Check these games out:

* Stockfish-Xiphos. The starting position, except White can't castle while Black can. Stockfish's starting eval at depth 31/48 is -0.20. (Yes Stockfish wins anyway, but it is *Stockfish*, the strongest conventional engine in the world, playing)
* Xiphos-Stockfish. The reverse game. Xiphos plays 1. Nc3 evaluating the position as 0.00, while Stockfish is -0.84 at depth 36/52.
* AllieStein-Stockfish. Played from the opening position with both sides able to castle. AllieStein gave 0.43 advantage to White at depth 18/57.
* Stockfish-Alliestein. The reverse game, Stockfish gave White a 0.47 advantage in the opening position at depth 38/59.
> 7 votes

# Answer
If you think of castling as an efficient way to play, say, Ke1-f2-g1 and Rh1-f1, then castling takes one tempi vs. three tempi to castle by hand. Therefore castling is worth **three tempi**.
> 5 votes

# Answer
Chess has one particular tactic or theme which cannot be ignored and that is king safety.

Since the rule is that if the king is lost, or checkmated, the game is lost; so the value of king is the most essential. I do not say that castling is the only answer to a safe king since there are many noteworthy games which have been won without castling, but castling is a standard procedure in many openings, and middlegames, since the king goes inside the high walls protected by its own soldiers, and gets the rooks connected.

The value of Castling increases because beside the King the Queen and the minor pieces are developed somewhere else in the Game . What I mean is playing with White the King's Bishop is developed on b5,c4,e2 or g2 mostly . The Knight is developed frequently on f3,e2 or a3 sometimes and we put our e and d pawns on e4 and d4 in most cases . The Queen leaves the stand from d1 and gets developed to some other Square .Now when it happens if the King remains in Centre it becomes exposed and susceptible to attack . No minor pieces are there to protect it .

When the King remains in the Castle then the Knight on f3 , the Pawns on f2,g2 and h2 serve as a barrier and the Rook stays besides as if the King is riding on a high elephant . Sometimes with the g pawn on g3 the Bishop stays on g2 . The King is protected and then the Forces can be coordinated on a particular area of the board for an attack . So Castling makes just too much sense .
> 3 votes

# Answer
I would check this by trying some experiments with a chess program to see how it evaluates positions. For example you could put in a position where one side is not castled and then the same position, if it is possible given the position, with the same side castled and compare the evaluations. You could do a similar test with the original position where the one side is not castled, but is able to castle, versus the same position but where the one side is not able to castle - because the king or rook already moved. Of course the evaluations would depend on the initial positions. If the positions are closed and not much is going on, you'd probably get a more stable value for castling from the experiments.
> 3 votes

# Answer
I am conducting some runs right now with some fairy armies battling each other and FIDE. I am thinking of taking away castling as an option from the slightly overpowered armies to better balance the games. Slightly overpowered armies are fairy armies with win% greater than 50% but less than 60%. The error rate of the samples is high, even at 200+ games, so it is difficult to calculate the true mean with precision, but I bet this will make the difference. I am betting half a pawn.
> 1 votes

# Answer
The rule is you have to castle in the first 10 moves, otherwise you will leave your king unprotected.

Most amateur players launch an aggressive attack and leave the king sitting there without any protection. If you study games from professional players, you will notice that they castle early in the opening.
> -3 votes

---
Tags: engines, strategy, castling
---


title: Identifying “big pawn” bishops

text:
# Question
Title: Identifying “big pawn” bishops
I use to trade my bishop pairs for opponent’s knight pair most of the time. But since my recent peak of interest in the game, I have been doing studying and learning. Thus, the bishop is one of my points of interest now.

I was watched this video by agadmator that demonstrated amazing gameplay by Aronian Levonm

```
[Title "Aronian Levobn-Vidit Santosh Gujrathi, FIDE Chess.com Online Nations Cupm 6/5/2020"]
[FEN ""]
[startply "96"]

1. Nf3 d5 2. e3 c5 3. c4 d4 4. exd4 cxd4 5. Bd3 Nc6 6. O-O Nf6 7. Bc2 Bg4 8. Ba4 Nd7 9. h3 Bh5 10. d3 e5 11. Re1 Be7 12. Nbd2 O-O 13. Ne4 Qc7 14. a3 a5 15. Ng3 Bg6 16. Bxc6 bxc6 17. Nxd4 exd4 18. Rxe7 Qd6 19. Re2 Nc5 20. Ne4 Nxe4 21. dxe4 Rfe8 22. f3 a4 23. c5 Qxc5 24. Bf4 Qb6 25. Rc1 c5 26. Rc4 f6 27. Qc1 Ra5 28. Rec2 f5 29. Rxc5 Rxc5 30. Rxc5 fxe4 31. fxe4 d3 32. Be3 Qe6 33. Rc7 Qxe4 34. Bd2 h6 35. Qc5 Bf7 36. Bc3 Qg6 37. Re7 Rxe7 38. Qxe7 Kh7 39. Qe5 Be8 40.  Kf2 Bf7 41. g4 Bb3 42. Ke3 Bc2 43. Kd2 Bb3 44. Ke3 Bc2 45. Kd2 Bb3 46. Qe7 Bc2 47. b4 axb3 48. Bb2 h5 49. g5 h4 50. a4 Kg8 51. a5 Kh7 52. a6 Bd1 53. Kxd1 d2 54. Qxg7+ Qxg7 55. Bxg7 Kxg7 56. Kxd2

```

On move 48, it can be seen that Black’dsbishop is trapped, which led to blacks defeat. Would this bishop be considered a “big pawn?”

Here are my observations.

1) Almost every example of big pawn that can found, such as here are situations where a player has played in such a way that they end up with pieces called *big pawn*. In the Levon game, it was trapped ( basically pushing your own pieces inactive(or passive) vs forced inactive(or passive))

2) Everytime a bishop is blocked by pawn and has restricted movement, it's supposedly a big pawn

3) In the book “What It Takes To Be A Chess Master” by Andrew Soltis, which is Wikipedia source for the definition of a big pawn,its seems just like a funny comment. Like, is it even supposed to be like a Chess term!

# Answer
> 3 votes
A "big pawn" bishop is kind of an informal term. In general it can be thought of as a bad bishop with especially limited movement. In the game you posted, that bishop could be considered a big pawn - there are pawns on its same colour, and they clearly restrict its movement.

However, whether it's technically a bad bishop is debatable, since the b3- and d3-pawns are fixed by White's pieces (not pawns). If the king or bishop moved away, perhaps these pawns would have advanced while the bishop was still on the board, allowing it to escape and not be considered bad or trapped.

To summarize, a big pawn is essentially a bishop which is both technically bad (pawns on its colour) and clearly inactive (lacking sufficient mobility on useful squares).

# Answer
> 1 votes
1. Indeed, every time a player has a restricted bishop, it was his choice! You can put your pawns in squares of the color you want. When you are left with a bad bishop, you probably did it to avoid a greater evil.
2. It depends. It's not as much about the squares it can't go. It's about what the bishop is doing on the squares it can actually go. In your example, the bishop on c2 is doing nothing.
3. It is indeed a joke term. "Bad bishop" is the non-satirical one.

---
Tags: terminology, bishops, bad-bishop
---


# Question
Title: Stockfish: different nodes numbers with identical calls
I ran Stockfish 2 times with the command `go depth 1`.

First time

```
info depth 1 seldepth 1 multipv 1 score cp 114 nodes 20 nps 10000 tbhits 0 time 2 pv e2e3

```

Second time:

```
info depth 1 seldepth 1 multipv 1 score cp 105 nodes 22 nps 22000 tbhits 0 time 1 pv e2e4

```

Why does the number of nodes increase from 20 to 22?

# Answer
It's likely due to Stockfish's transposition table (essentially a fast lookup table that Stockfish can use to refer back to positions it evaluated before). During your first run, information about visited positions was stored in the table. Then on the second run, Stockfish may have looked at some of Black's moves after depth 1 (since it's already evaluated all states at depth 1).

SmallChess' answer to this question may be useful if it's still confusing:

How to read score from stockfish - inconsistent response every call?

Edit: to test if it is the transposition table behind this, try to reset it after the first run (close the whole program if you can't figure out how). Then on the second run, the number of nodes should be the same (as well as the centipawn evaluation).
> 1 votes

---
Tags: stockfish
---


# Question
Title: How to proceed with the book "Pawn Structure Chess" by Andrew Soltis?
Should I memorize everything in the book, or use it in some other way?

# Answer
> 9 votes
I'm not familiar with the book itself, but for learning pawn structures it isn't important to memorize every single thing. The key is to understand the general ideas behind each structure. E.g.: what are the main plans, which pawns are weaknesses, what squares work well as outposts for pieces, can the structure be changed as the game goes on, etc.

Knowing these things would be useful if you were playing a real game with the structure in question. And the key is to *know* them, not to memorize them by rote. If you can understand why certain structures give rise to certain characteristics, then you could generalize when facing a new structure over the board.

---
Tags: strategy, books, pawns, pawn-structure, middlegame
---


# Question
Title: Websites for online all-vs-all tournaments
We have a small chess club with about 15 people, whereof about 6 - 10 people comes every week. We play a blitz tournament where everyone meets everyone.

During corona, we do not meet physically, and the problem being that we don't know how to host the tournament where everyone meets everyone exactly once. Technical knowledge is very limited for some players, so managing the scoring manually is not an option.

Is there any website that offers this type of tournament? All we can see is where tourneys has x rounds and swiss pairing system.

# Answer
Sadly I don't know of any such site, but I also manually conduct tournament in my small group( 12 members) via Lichess.

Just manually draw a Swiss tournament and setup a Discord for your club. announce the pairings and format and the players can decide the time of play with their opponents. collect the results and repeat the same for the next round.

Edit : Lichess is adding a Swiss tournament feature (source)
> 3 votes

# Answer
I know a site where you can create tournaments with your rules:

www.lichess.org

I play myself with many other people's there. Try it. Lichess has this game mode already
> 1 votes

---
Tags: tournament, online-chess
---


# Question
Title: Can anyone please explain why this position isn't a draw?
I was watching this game on Lichess. Both of the players have the same resource i.e., the king and only a bishop. The bishops on the board are of the opposite color. But the game was continued and one of the players flagged on time.

I ran a full computer analysis and the engine has shown the position as a draw. But, since the computer allowed the player to continue the game with that resource, my question is whether it is possible to win a game with "ONLY" a bishop, provided your opponent only has the same? If yes, then what should be the checkmate position? and will the result be different if your opponent has the same color bishop?

```
[FEN "8/1k1b4/8/2B5/8/K7/8/8 w - - 0 1"]

```

# Answer
> 13 votes
According to the FIDE Laws of Chess:

> 5.2.2 The game is drawn when a position has arisen in which neither player can checkmate the opponent’s king with any series of legal moves. The game is said to end in a ‘dead position’.

The game position you show is not a draw because there are series of legal moves ending in checkmate for either side.

```
[FEN "8/1k1b4/8/2B5/8/K7/8/8 w - - 0 1"]

1. Kb3 Be6 2. Kc3 Kc7 3. Kd3 Kd7 4. Ke3 Ke8 5. Kf4 Kf7 6. Kg5 Kg8 7. Kh6 Kh8 8. Bd6 Bg8 9. Be5#

```

Of course black's moves were stupid. That doesn't matter. They were all legal moves and so were all white's moves. A similar set of moves could be constructed to allow black to checkmate white. The sensible thing to do is to agree a draw in this position, particularly if there is an increment.

If there is no increment and the player with more time wants to be spiteful then they can play on and try and flag the other player. Of course they shouldn't do this if they are playing Gata Kamsky GM FFL :-)

With same colored bishops this is not possible. The opposite colored bishop is required to block one of the king's escape squares.

---
Tags: rules, endgame, online-chess, draw, bishop-endgame
---


title: How to visualize in chess?

text:
# Question
Title: How to visualize in chess?
Skip to 2:08:27 in this video https://youtu.be/nK4SNEbMn7s. What exactly is GMHikaru doing that?How can I be able to do that?Does it comes naturally with practice or their are exercises?

# Answer
Okay, this sequence is very impressive and Nakamura is a "beast". So I don't want to be too pessimistic but I'm afraid that this kind of performance, which consists in calculating at the speed of light a sequence of movements without error, is only possible for the highest rated players.

There is, however, a (little) hope. In the excellent perpetual chess podcast talk, GM Rustam Kasimdzhanov talks about Nakamura. He notices about his play and the play of some of the top teenagers in the chess world, including GMs Nodirbek Abdussatorov and Alireza Firouzja that they never blunder, even under stress, and their tactical perception of the position is extremely clear. The reason could be the thousands of games, especially blitz games, they have played. So go practice!
> 3 votes

# Answer
As was pointed out before me, that level of calculation is extremely impressive. You are at the end of the day looking at one of the top chess players in the world and, arguably, in history to this day.

Apart from that note, you should know that visualization is a matter of practice, and the acquisition of such skill is not different to that of arithmetic calculation. If you calculate a complicated sum today just in your head, a more complicated one tomorrow, a more complicated one the next day, etc., eventually you'll be able to quickly calculate sums and substractions. People may look at you add 1304592 + 2948535 in relatively small time and say "what a genius", but it's not being a genius it's just practicing a lot (the genius part just makes the learning curve faster).

So practice a lot. Get a book on positional chess and another one on tactics and go through the problems on your head. Try to visualize the resulting positions and not only visualize them but also judge them (best for white, equal, winning for black?). Do it A LOT. And do it when you play too. Don't just make moves (unless they are obvious or superficial ones), but say "I play x move, he plays z, then y, then v...", until you reach a conclusion (the position is best for me so I should go for this, the position is equal, etc.).

There will be MANY times when you miss a move on your calculations, maybe a crucial one that makes you lose. That's okay, it's normal. Just do it again on the next game and try to do better. But, bottom line, just **do it a lot**.

Once you acquire the *habit* of doing it, you'll do it without realizing it and you'll be practicing without realizing it during all your games.
> 3 votes

# Answer
Not trying to belittle this achievement, but I think the hardest part is to speak as quickly as Hikaru does.

I do think that it is impressive but not to the extent that the other answers suggest. Reasons:

* black's position is clearly won by a variety of ways, in fact the cleanest and fastest way would be 1. Ne7 instead of Bf1
* the sequence that Hikaru calculates consists basically of **only moves with check each move**. It is a lot harder to calculate positions where there are many options including quiet moves.
* white's options are extremely limited because black is threatening mate in one
* it is a show without any consequences. I am sure that when playing a real match, Hikaru would slow down just to be sure not to make a mistake.
* judging from a single instance is meaningless, I am sure Hikaru is right most of the time but there might be the occasional blunders when calculating at that speed

To answer the OP's question. Yes, with practice (tactics puzzles, games) you will improve. Perhaps not to the level of Hikaru but half that speed is realistic IMO.
> 1 votes

---
Tags: online-chess, middlegame, board-vision, visualization
---


# Question
Title: How to understand Stockfish's source code?
I want to code a Chinese chess engine, and I want to modify the Stockfish source code to do so, but the Stockfish source code is too hard to understand. There is no document that explains everything. I don't know where to start. For example, today I tried to understand the bitbase.cpp file. This line of code in this file is not well documented:

```
constexpr unsigned MAX_INDEX = 2*24*64*64; // stm * psq * wksq * bksq = 196608

```

I really don't know where to ask questions about these kinds of things. It's open source but it seems to be understood by only a few people. Please give me suggestions to understand the source code better.

# Answer
> 6 votes
I believe the line you quote is about probing KPK tablebase endgame. There are 64 squares for the king, and 24 squares for the pawns (mirrored from file A to D). Nothing special, just how Stockfish indexes the bitbase data structure.

The code is not going to work in Chinese Chess for obvious reason.

> This line of code in this file is not well documented

No, the line was fully documented. Please look at the code file again.

> Please give me suggestions to understand the source code better

In the open source world, if you don't have sufficient coding experience you just can't do anything. You may ask on the Fishcooking forum, but you will still need decent programming experience.

---
Tags: stockfish
---


# Question
Title: How should rooks be developed in the opening?
The opening is definitely a weak area in my chess game and I always feel like my rooks sit unused until well into the middle game (?). Is that just how things go, or is there a strategy that allows development of the rooks in the opening?

I'm aware of castling as a way to get a rook towards the middle files (of course). But I always feel like I'm neglecting the rooks when I play.

# Answer
> 22 votes
That's actually not very surprising. In many openings, the rooks don't participate until fairly deep into the middlegame. You touch on the reason in your question - the rooks have to wait until all the other pieces are out of the way in order to develop.

The specific strategy for rook development will depend on the position, but generally speaking, the rooks belong on the *open and half open files* in the middlegame. In the endgame, rooks belong *behind passed pawns*. Also in the late middlegame and endgame, rooks are very useful on the *7th rank* (and to some degree the 6th rank as well).

In most openings, the rooks for white will usually come to d1 and e1. Obviously that's a huge generalization, so don't take that as gospel truth. Larry Christiansen has said that "when in doubt \[about which rook to move\], play the 'a' rook to d1". The other rook (usually coming from the f file after `O-O`) should either stay on f1 or move to e1.

One last comment - often the best way to make use of the rooks is to double them so that they can invade into the enemy camp. Usually your rooks aren't going to reach the 7th rank in the middlegame because there are too many minor pieces still on the board, but they can still be very useful when doubled and on open files so that they *threaten* to invade into the opponent's position.

# Answer
> 10 votes
One way NOT to develop rooks in the opening is via something like

1. a4 d5
2. Ra3

or

1. h4 d5
2. Rh3

I (a duffer) played a series of twenty or so games against someone who insisted on opening like this. He never won a game against me.

Best advice is to follow the common wisdom that rooks are usually developed last.

# Answer
> 9 votes
**Rooks should usually be kept back in the opening and early middlegame, so they don't become "fodder" for minor pieces like knights and bishops. After some of those pieces are exchanged, then rooks come into their own.**

When the time comes, the rooks should be placed on *open* files (vertical lines where the pawns have been exchanged). These are usually the d and e files, sometimes the c or f files, occasionally the "side" files.

A single rook is a menace to unguarded opposing pieces on the file. "Doubled" rooks (one behind the other) are a menace to opposing pieces on the file unless they are *well* guarded. The exception is if the opponent can "close" the file using a minor piece guarded by a pawn (exchanging a rook for such a piece and a pawn is seldom a good idea). That's why you want at least some of the minor pieces off the board before you start deploying your rooks.

# Answer
> 7 votes
There are some situations where rooks become active in the opening, but they are rare, and often only enabled by blunders of the other side.

One example: White has castled with a knight on f3, black has not castled and the black bishop pins that knight. Now sometimes `h3` can be met with `...h5!?`, and if white accepts the sacrifice with `hxg4 hxg4`, the black rook enjoys suddenly an open file, and white is in serious trouble if the black queen can join the attack.

# Answer
> 5 votes
You want to get the rooks connected and you want to put them on open files.

# Answer
> 2 votes
A "rook lift" is the attackers best friend. A rook can only be lifted through a break in the pawn chain. Pawns must be exchanged to develop a hole through which rooks can be lifted and this is simply termed: "opening lines"... i.e. pawn exchanges open lines.

Cecil J Purdy- an Australian correspondence player\- whom Bobby Fischer called one of the games best teachers, said that you want a plan for both rooks to enter the game by the 12th move.

Rooks can also be called, "The Heavy Pieces", and the simple idea is to get your heavy pieces into the game! Be aware that some people say that when you take one of the rooks, "The back is broken!"

A stricter set of rules says that: place your Rooks on open files or openable files.

It has also been said that you should never start your final attack until until your Queens Rook is in the game.

You will find by looking through most games that most rooks are connected and centered by the 12th move.

Always remember that doubled rooks are more powerful than separated rooks .. separated rooks is better than having only one rook of course: once again- when 'the back is broken' it is a disadvantage under normal circumstances.

# Answer
> 1 votes
One way to develop rooks in the opening is to castle and then storm an attack on the opponents castle using rooks bishops and queen.

---
Tags: opening, rooks, development
---


# Question
Title: Is there any website that allows you to check if a position has been played before?
Is there any website that allows you to check if a position has been played before? I want to analyse a game and I want to check if it has been reached before. Any suggestions?

# Answer
Look up "Chessbase Live Database" on Google and click on the first result. You should be taken to this url:

https://database.chessbase.com/?lang=en

You just enter moves and click the magnifying glass button, causing a list of games played to show up.
> 4 votes

# Answer
Look up "365Chess.com", which is a chess games database online. Here is the link for searching a position:

https://www.365chess.com/search\_position.php

You can enter moves, import pgn, or fen positions.
> 4 votes

---
Tags: analysis
---


# Question
Title: GUI for stockfish that can analyse the full game
I am looking for a GUI for stockfish that can analyse the whole chess game and give me the following output: For every move in the game, it should give me a list of N (let it be 3) best moves with a score corresponding to each of these moves.

Here is a good example. As you see, after each move I can see a corresponding best replies and their score. I need this to analyse a few hundred games automatically.

**P.S.** just to be clear. I do not need a software to do this with few hundred games. If it can analyse one game in the way I want, I can make it analyse all games. I just wanted to show a high level picture what I am planning to do. Sorry, that it was misleading.

# Answer
Yes, this is possible. But in a slightly crude way. It is possible with Arena Chess GUI 3.5. What you need to do is the following-

1) Open the pgn file in Arena GUI

2) Confiure any engine with Multi-PV enabled to your choice of top "N" moves.

3) Now open Engines \> Automatic Analysis

4) In Source tab select "List of EPD/PGN Files" and Click the icon for adding all PGN files for which you need the automatic analysis.

5) Check "WhiteMoves" and "BlackMoves"

6) If the PGN file contains multiple PGNs then select the range of game numbers you want it to process

7) Select range of move numbers if needed

8) Now go to the Output tab and select "Write in protocol file"

9) Now start the analysis and after its done, you can check the protocol file. The last section for each move contains the best "n" moves calculated by the engine. Parsing this protocol file should be really easy if you want to automate it.

Note: The pgn itself can be altered to add the scores, but it does not add multiple moves at one shot.

Example output in the protocol file:

```
   ---------------------------------------------------------------------------
16/25   00:01      3,444,292    2,274,961   -0.04   0-0 Ne5 Nc6 Nd2 Rd8 Qb3 Bd7 0-0 Qc7 Re1 h6 Ndf3 Ne4 Nxd7 Rxd7 Ne5 Bxe5 fxe5 Qb6
16/25   00:01      3,444,292    2,274,961   -0.08   Nc6 Ne5 Bd7 Nd2 0-0 Qb3 Qc7 0-0 Rfc8 Re1 h6 Ndf3 a6 Bd3 Na5 Qc2 Nc4 Bxc4 dxc4
16/25   00:01      3,444,292    2,274,961   -0.08   Bd7 Qb3 Qc7 Ne5 Nc6 Nd2 a6 0-0 0-0 Re1 Rfc8 Bd3 h6 Ndf3 Na5 Qc2 Nc4 Bxc4 dxc4
8/16/2014 12:24:59 PM, Time for this analysis: 00:00:02, Rated time: 00:04

```

Of course it also has flexibility to tailor what gets dumped into the file as well.
> 5 votes

# Answer
Check this out !

http://cpuchess.com/

It's extremely simple. Just paste in you PGN text in the web interface and click for it to analyze the game. It will plot an evaluation chart which helps you to easily find blunders. Blunders are spikes in this chart, which will be highlighted in red. I'm not sure if this engine is strong or not, but it has many engines and it your machine's full processing power to analyze.
> 2 votes

# Answer
**Free Creatica Chess Game Analyzer for MS Windows** Maybe that's a solution: =\> https://chessgame-analyzer.creatica.org/index.html

Easy to use tool for MS Windows.

Right click on a \** pgn file \** and select "Analyze". The newly created PNG file with analysis information is automatically opened in your standard chess GUI such as Scid.

Many parameters can be set for a desired result, such as the number of variants: https://chessgame-analyzer.creatica.org/customize.html
> 1 votes

# Answer
Try TarraschDB analysis. Just paste the PGN, pick your move to start the analysis and click Start. It will give you the best 4 moves and you can use Capture All if you want all 4 best moves or just Capture Top to select the best move.

Link: https://www.triplehappy.com/
> 0 votes

# Answer
Check out Arena Chess GUI 3.5.1.

It works with Stockfish, and comes with built in Engines. You can also download additional engines for it and pit them against one another in tournament mode.

Also Arena with Stockfish supports Syzygy tablebase.

It's a very strong gui.
> 0 votes

# Answer
Check out http://chess555.com . It also includes Openings Explorer and you can get games for any position up to move 20.
> 0 votes

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Tags: analysis, engines, stockfish
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# Question
Title: Why does Stockfish undervalue pawns when compared to the classical "a piece is worth three pawns" approach?
I was taking a look at values engines give to pawns and piece and was quite shocked by Stockfish values for middlegame (Mg):

* `PawnValueMg` = 128
* `KnightValueMg` = 721 ~ 5.6 pawns
* `BishopValueMg` = 825 ~ 6.4 pawns
* `RookValueMg` = 1276 ~ 9.9 pawns
* `QueenValueMg` = 2538 ~ 19.8 pawns

So this is way far from the standard "1 piece equals 3 pawns approach", and I was curious about the reason behind it.

Also, the fact that bishops are 0.8 pawns more valuable than knights called my attention.

I'm aware that this is a small part of Stockfish's (or for that case, any serious engine) evaluation function, but even so it seems like a really big different from the classic approach.

# Answer
> 48 votes
I am not an expert on stockfish source code, but my understanding is the following.

Humans:

It is true, that the *1 piece equals 3 pawns approach* is pretty accurate, surprisingly so. However as you are probably aware, when evaluating a position, we consider many other aspects as well, such as piece activity, space, king safety, etc. The difference however is that **we don't assign actual numerical values to these other factors.**

Stockfish (or similar engines):

Unlike humans, engines assign numerical values to all factors. The numbers you mention are just **a small part of the evaluation function.**

Check out the middlegame evaluation function for stockfish. On that page you can also modify the board to see the evaluation and you can visit the specific functions such as \`piece\_value\_mg' which is concerned with these numbers.

As you can see, just the piece values of all pieces amount to 9326. However there are many other functions which add to the evaluation. Most importantly, **not all of these extra functions treat pawns and pieces equally.**

For instance:

* \`Psqt mg', gives values to pawns only, depending on their position on the board. As you would expect, pawns in the center are more valuable (pawn on e4 instead of e2 is +24 points)
* another pawns only function: \`Pawns mg' gives points depending on the pawn structure (isolated, doubled, connected pawns, etc) also here you can gain several tenth of points for the pawns (but not for the pieces).

To be fair, there are also functions that only deal with pieces such as \`Pieces mg'. However note that they can also give a penalty (negative value) to the total evaluation. In fact for the starting position you have -63 from that function.

---

In summary...

Stockfish has a much more fine grained evaluation function than we humans do. The pure piece value from stockfish cannot really be compared with the human piece value.

In stockfish pieces and pawns can gain points in other ways beyond the values you mention. Furthermore, stockfish does not consider the piece on its own, but also how it relates to other pieces, e.g. whether there are doubled pawns, an outpost, etc.

If you check out the code, these other factors are each in the range of several ten points, so if you take them all together you might very well gain the 100 points necessary for the pawn to be 1/3 of a piece.

Mathematically you could also consider it as a kind of approximation or averaging in which you assign a single number (human piece value) for the very complex system that stockfish uses. There is no reason that the average value (human piece value) has any relation to one of the parameters (ValueMG) in the stockfish universe.

I really recommend to see for yourself at the link how much more complete the stockfish evaluation is.

# Answer
> 10 votes
Please note that those values are "abstract", later to be modified by the specifics of the position. For example, even though a knight appears 0.8 pawns less valuable than a bishop, it could be that bigger bonuses are awarded to well-placed knights than for well-placed bishops, turning the balance around.

It's also worth noting that the "3 pawns equal a piece" is, for all practical purposes, meaningless. In certain types of positions (those with powerful attacks against the king, for instance), the extra pawns can be useless against a piece. In endgames, three pawns often defeat the piece, specially if not a lot of extra pawns are left

# Answer
> 7 votes
The value of a piece or pawn will depend greatly upon how well it is placed. The common 1/3/3.5/5/9 values are reasonable estimates for pieces which are placed decently but not amazingly well. For various reasons, it may be easier to have the baseline score for a piece represent a piece which is either much worse than typical (so that most pieces would have an adjusted score that was higher), or perhaps have it represent a piece which is much better than typical (so that most pieces would score lower). As an exaggerated contrived example, consider something like:

```
8/p/Pp/RP/1P2nn/RP/P/5K1k w - - 0 1

```

Even though White nominally has a substantial material advantage (up twice the Exchange, plus three pawns), Black cannot lose without capturing any of the White pawns or pieces. Although trading a pawn for a rook would normally be a good trade, in this case it is a very bad one since White's pieces are completely useless. Black will nominally be able to trade a pawn for a rook, which would seem like an advantage, but doing so would enormously increase the value of White's pieces.

If it is White to mov Playing with this example, I think White should be able to eke out a draw, and Black certainly should be able to do at least that. Playing against Stockfish level 3 on lichess.org, however, I was able to win as both sides because Stockfish overvalued the material at the left and thinks it's worth trading for (I think White should be able to eke out a draw by moving R3-a4, and then a3, but Stockfish didn't find that playing as White, and there might be a way for Black to capture the rook in a situation where Black could then forcce draw by perpetual check/repetition, but Black should have no excuse for losing here.

Even in less contrived situations, Stockfish sometimes fails to adequately distinguish between pieces which aren't currently in the fray, but are going to get there, versus pieces which can be very cheaply kept out of the action while the opponent has a substantial majority of the immediately-effective material. A common feature of games between neural networks and Stockfish is that Stockfish ends up letting some of its pieces sit out of the action while the opponent uses its power majority to edge out further advantages, until by the time the blocked-up pieces get to move, the game is already lost.

Incidentally, I was just playing with another variation on that example (black to play)

```
7K/p7/Pp6/RP6/QP4q1/RP3k2/P7/8 b - - 0 1

```

Black has a mate in four, but Stockfish, even if set for the highest level on lichess.org, will stalemate White via Qg6 rather than achieve victory, probably because any move that continues play with such a large material imbalance is seen as so massively inferior to stalemate that it's not worth investigating further.

# Answer
> 3 votes
I'm afraid it was machine tuned. Nobody knows exactly why. It's like nobody really understand the network weights in LC0. In any case, 3 pawns = a piece is nothing more than a general guidance for chess beginners.

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Tags: engines, stockfish, evaluation, pieces, point-value
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