# Question
Title: Method to study chess puzzles way above your level
I have a collection of middle-game chess puzzles classified in levels. I can solve most puzzles in the first level after a few minutes, and some of the puzzles in level 2.

But for higher levels there is no hope I can solve any of them, even if I tried for a thousand years. Nevertheless, those are supposed to be interesting positions with hidden treasures, and I wonder if I can still learn something from them. What should I do? Play against a computer from those positions until finding the solutions? Look at the solutions and memorizing them?

# Answer
Chess puzzles (and to a large extent playing chess) are based around recognizing certain patterns or motifs which help you to quickly assess a position and to visualize potential lines without the need to calculate move by move in your head.

Chesstempo has a good list of tactical motifs and positional motifs. It is important that when you solve problems (or when analyzing your games) that you realize which motives (usually there is more than one) apply to this problem. If you cannot solve a problem on your own it is fine to look up the solution or to get help from a computer, but make sure you understand the solution (i.e. match them to motifs/patterns). Again chesstempo is very useful for this as it shows you the motifs of each problem as "tags" (after you solved it or after you failed to solve it).

Once you have built a repertoire of patterns/motifs in your mind you should have a good basis to solve more complicated problems as well.

Another factor could be visualization when calculating long lines, but there is not much you can do about it other than concentrating, playing games, analyzing games, solving puzzles.... basically everything you should be doing anyway.
> 5 votes

# Answer
This is a decent question because it tries to delve into the thinking process of solving a tactical puzzle. Of course, Tactical motifs and Positional motifs are important but you gain those by experience or study time, and I believe what the asker is looking for is a methodology he can apply to a difficult puzzle in hopes of solving it. So, with that in mind:

Note all captures, checks, and unprotected or insufficiently protected pieces. Visualize each separately, alone. When you do this, you begin to connect some dots in the position, like "if I take here and he takes, that leaves this piece undefended...", etc., etc.

Note all potential double-attacks, probably the most common tactic in chess.

Visualize all avenues of attack for every long-range piece - Bishops, Rooks, and Queens; this means mentally *ignore* any obstructing enemy or friendly pieces, i.e., Bd3 looks down the b1-h7 diagonal regardless if there are black or white pieces in the way. This paves the way for *clearance* sacrifice ideas, and discovered attacks.

Visualize all potential knight-forks, and all knight-forks after the move of the knight.

Honestly, I would start there and avoid using the computer. It will not teach you anything you cannot figure out yourself - you just need to be persistent.

I would also *write it all down* so you can drop the puzzle and come back to it later. You are gaining good habits by doing this, and it gives you valuable references.

Only then when you are completely spent on the puzzle do you pass it to Stockfish.

2c.
> 2 votes

# Answer
Delivering instruction in how to solve tactical problems is much too complex a topic to address in a forum post, unfortunately. The main points are these:

1. You need to learn to recognize 1st-level tactics when they appear. Most players can do this. 1st-level tactics include things like forks, skewers, pins, etc. You will only be able to exploit this skill (by itself) if your opponent blunders.
2. You need to recognize situations that may lend themselves to a 1st-level tactic after a short sequence of 1 or more forcing moves. Forcing moves are mate threats, captures, checks, and threats to capture. I call these 2nd-level tactics, because they involve a setup before the 1st-level tactic appears.

Such situations include possibilities such as being able to force an alignment of the opponent's queen and king that may then become vulnerable to a pin or skewer.

3. Finally, you need to recognize situations where no 1st-level tactic is available, and the opponent has replies that would frustrate a series of setup moves that would otherwise work. It may still be possible to employ one or more other, supporting tactics to eliminate those replies, thus allowing the setup to work. Then, the 1st-level tactic will become possible.

I call these 3rd-level tactics, because of the additional preparatory moves that must be played to eliminate the opponent's defensive options prior to (or during) the setup to the final, 1st-level tactic.

4. Once you have mastered some degree of 3rd-level tactics, you will be able to move onto 4th-level tactics. These involve *multiple* 2nd- and 3rd-level tactics in a sequence.

This is my personal approach to understanding combinations, and there is much more theory around it than I can relate here. I am writing a book to cover this gap in current teaching.

Until you can find such a book, I strongly recommend George Renko's Intensive Chess Tactics Course, now in its 2nd edition, from ChessBase. Renko has spent many years codifying this classification of tactical themes (of which he has enumerated 112).

Please note he has made a claim of plagiarism against Convekta for their product Encyclopedia of Chess Combinations by NM Kalinichenko, which is an exact copy published several years after Renko's. Snopes.com has confirmed this claim. For this reason I advise against purchasing the Convekta product.
> 1 votes

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Tags: learning, tactics, puzzles, study
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# Question
Title: What is the number of chess position for each move?
I have read some articles that chess has a numbers of 10 to power of 120. Can some one can throw lights to it:

White 1st move: No of Position White 2nd move: No of Position till White 72nd move: No of Position

Similarly for Black

Black 1st move : No of Position Black 2nd move : No of Position Till Black 72nd move : No of Position

Your help will improve one's chess understanding better and will bring some hope to readers relating to chess can be solved.

Thank you for your time Raman Thanks for the first answer

# Answer
> 2 votes
You are misusing the word "probability" in your question. 10 to the power 120 is known as the Shannon number and is a lower bound for the game-tree complexity (number of different games of chess). This has nothing to do with probability. Also this number of different games is not the same as the number of possible chess positions (which is estimated as 10^43).

If you look at the starting position in chess, each player has 20 possible moves (16 with the pawns and 4 with the knights). So the number of possible games of 1 move (2 plies, i.e. one white move and one black move) would be 20\*20 = 400 already.

Now the number of possible moves increases initially because your pieces get more space. The number of possible second moves is not fixed, but will depend on the first move. So it is impossible to give an exact answer to your second question. But you can do some estimates...

If you say that at each move you have a choice between 30 moves (this is an estimate) and if you say that an average chess game lasts 40 moves (80 plies), you end up with the number of possible games equal to: 30^80=(30^2)^40 which is approximately equal to 1000^40=10^120.

This is a very rough estimate but is sufficient to show that chess is incredibly complex and is not going to be solved anytime soon.

You might also like the Numberphile episode on the topic

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Tags: statistics
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# Question
Title: Fritz for Fun 13: how do I add positions to a new database?
My aim is to create a database of endgame positions taken from Van Perlo's *Endgame Tactics* in Fritz for Fun 13.

I've created a new database, but I do not know how to add games or positions. How do I add content to my empty database?

# Answer
> 0 votes
This is one way to do it:

1. Create a text file of PGN positions
2. Open that PGN file in Fritz for Fun. Each PGN can be seen as a line in the database view
3. Either play the position against the computer, or turn the engine off and play through the variation. If your variation differs from that in the PGN, the 'new variation' dialogue box will open

# Answer
> 0 votes
I'm not familiar with Fritz for Fun 13, but I have information about Fritz 13, which I will assume is the basis for your variant.

I'll also assume that you want to add a game / position manually, rather than import one (or a collection) from, say, a PGN file.

New Game: You can enter the moves for a new game by simply setting the players to 2-player mode, instead of player vs Fritz. If you can't figure out how to do that, turn on "Infinite Analysis" mode with Alt-F2. That will prevent Fritz from entering an engine move. Then, just enter the moves.

New Position: Choose the menu option "Insert, Position Setup". Then, clear the board (in Fritz 13, it is pre-populated with the start position), and drag-and-drop or click-click your way to populating the position. Hint: In Fritz 13, if you click the white piece in the legend, and then left click on a square, you get a white piece. If you *right-click* on a square, you get a *black* piece. So, you can save yourself about 30-40% of your setup clicks by just selecting white pieces.

Finally, specify the side to move, using the appropriate checkbox. If one of the kings is in check, of course, you cannot save the position until that side is specified as having the move.

You may have to specify castling rights (kingside and/or queenside) for either white or black or both, if the kings and rooks are in their original positions, but the setup wizard (dis-)allows that side's castling erroneously. However, the wizard settings are generally correct, in my experience. Only when either the king or the rook have moved from their home squares *and then returned to them* will the wizard's settings be wrong. Don't worry about the king being in check or any of the relevant castling squares being under attack; the move entry function will prevent an immediate castling attempt in that situation.

Then, confirm that you're done with the position setup using the Ok button. You will then have an open game window (but *not* a saved game).

Saving Games and Positions: The last step is simply to save the game/position. In Fritz 13, if you had clicked on a database (or had a list open) before you started the game/position entry process, that database would be where the game/position is saved by default if you use the "Save" menu item. Otherwise, you have to navigate to the appropriate database using the "Save As..." menu option. So, I generally select my database first.

Tip: You can actually use a copy/paste operation to save the game from an open game window into a database. There are tons of ways to specify "copy", including right-clicking in the Notation pane, or by typing \[Ctrl\]\[C\]. Once you've put the game in the clipboard (the results of this copy action are invisible, but trust me, it's there), you can paste it (any way you like) into a selected or open database, a Notepad window or other text editor, or an email as a text attachment. But watch out; if you paste it into a database window, different versions of Fritz are inconsistent about whether a subsequent Replace operation will affect the pasted game. To be safe, I close the open game window, and then open the game from the database list. That ensures that a later Replace will put the game back in that slot.

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Tags: engines, endgame, database, fritz
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# Question
Title: Playing stockfish level 3000 on Arena 3.5.1
I downloaded Arena 3.5.1, and then downloaded stockfish from https://stockfishchess.org/ it had 4 files:

stockfish\_8\_x32.exe stockfish\_8\_x64.exe stockfish\_8\_x64\_bmi2.exe stockfish\_8\_x64\_popcnt.exe

I loaded the four engines to Arena, but it always says at the top (2000), which means level 2000, how do I make it level 3000+?

Also when I am playing on Arena, it takes 15 seconds and more for each step from the computer to play, is this right?

Thanks, am still new to all these things.

# Answer
You need only one of the four engine files. The four executables are compiles of the same source code for different CPUs. They differ in speed only; sorted in descending order these are: stockfish\_8\_x64\_bmi2.exe, stockfish\_8\_x64\_popcnt.exe, stockfish\_8\_x64.exe, stockfish\_8\_x32.exe. Keep the fastest which runs on your system and delete the other three.

> I loaded the four engines to Arena, but it always says at the top (2000), which means level 2000, how do I make it level 3000+?

This number doesn't set the playing strength. It has informative purposes only. You can change it as follows:

1. Open 'Engine Management' (F11).
2. Click the 'Details' tab and select Stockfish from the list.
3. Click the 'Information' tab in the right part and type the desired value into the 'Rating' field. If this field is empty, a default value of 2000 will be used.
4. Close the dialog and start a new game to display your new setting.

You can't set Stockfish to play at a given Elo level. If you want to weaken it, change the Skill Level in the engine settings (Ctrl+1, if it's loaded as 1st engine). '0' is the weakest setting and the default value '20' means full strength.
> 3 votes

# Answer
Are you beating it when it says 2000?

As of December 2016 Stockfish 8's Elo computer rating was 3478 as seen CCRL. This was calculated by pitting Stockfish against other Chess engines under controlled conditions and compiling statistics. The testing framework used by Stockfish in those competitions can be found HERE.

Rest assured that the 2000 you're seeing is more a problem with Arena's inability to calculate a meaningful rating, than Stockfish's ability to play at the highest levels.

In order for any rating to be believable, lots of games (data) in controlled conditions needs to be seen (for humans those are competitions). I'm apt to believe the CCRL rating before Athena.

Athena is known to struggle with accurate rating calculations. So to answer you: be wary of believing Athena.
> 1 votes

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Tags: stockfish, arena
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# Question
Title: Is there a Windows based command line tool to convert cbh to pgn?
I see that there is code for an Android app available at https://code.google.com/p/cb2pgn/, but I wonder if anyone has taken the time to make a standalone .exe that does the job?

# Answer
> 1 votes
If you have Chess Assistant (CA), it will do the conversion for you. For example, within CA just right click game on the game and go to Edit --\> Copy to Clipboard and pick pgn.

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Tags: software, database
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# Question
Title: How can I analyze and annotate multiple (500) games with stockfish?
I want to analyze multiple games in one batch with Stockfish. Apart from Scid I do not know any other tool which will do it faster or better. What are som alternatives to Scid with better performance or annotation quality in mind?

Scid allows me to set time or depth (not both at together), put score, put variation, multiple lines analysis.

# Answer
> 2 votes
If you are using Android, Analyze This (Free) is the way to go, just use the 'Auto Analysis' feature.
If you are using windows, Arena Chess is the way to go (you need to install Stockfish, and load the games in a single PGN, and turn on Auto Analysis ...)

Hope this helped, ~CSS

# Answer
> 1 votes
Chess Assistant and Chessbase would do it but of course you have to pay for the software.

# Answer
> 0 votes
Would recommend creating an account (free) on Lichess.org, and importing the pgn there. You'll have options for auto-analysis with lichess (~2800 rating), as well as annotating the games. This will avoid you having to download anything onto your computer or phone.

I've used Analyze This, and would definitely recommend it as well, but free users don't get strong auto-analysis, so I don't think it will fulfill your purpose.

Hope this helps!

# Answer
> -2 votes
ChessBase's Fritz (any version less than 10 years old or so) will accept any UCI-compatible chess engine, including Stockfish. You should be able to find a used copy for about $15-20 at most. You don't need to worry about the version, because the functionality of annotating the games has been around a long time, the deciding factor in analysis is the engine, which you're going to replace anyway.

Fritz can process PGN files, but I find it's more helpful to convert the games database to ChessBase's format (.cbh, etc.), so that training questions and the more exotic glyphs that are generated by Fritz from the engine's output can be stored. I haven't tested the impact of file format on processing speed, but I'd expect it to be minimal, as long as your games database to be processed is 1 MM games or less in size.

Regarding speed, a lot depends on your CPU and memory configurations. I use a 1024 MB hashtable, though you can go up to 2048 MB. I also use a quad core AMD Athlon processor running at about 2.9 GHz, and set the engine to use 4 threads. The speed increases pretty linearly with each additional core, so if you have 8, you'll almost double it.

I use Stockfish 7, and set the engine parameters to a depth of 22 or 23 ply, with unlimited time. I've found that the proportion of games where deeper analysis makes a difference to the best move selection is very small (well under 5%), and each additional ply increases the work exponentially, so there's a significant tradeoff in speed for additional depth of analysis. My configuration will process about 15 games per hour (games are about 36 moves long, on average).

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Tags: analysis, stockfish, scid
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title: How to use TWIC files for study

text:
# Question
Title: How to use TWIC files for study
I'd like some feedback and suggestions on how you use The Week In Chess pgn/cbv files for study. Here are a few things I do with them:

**1. Play from a won position** \- here we go down the list of decided games and using a chess engine, get to the point in the game where the evaluation flips to +/- 2.00 or greater. Play the game out at that point against the computer and try and find a winning continuation.

**2. Update your repertoire** \- Using the ECO Keys, gather the games in your main repertoire from the TWIC file and at least review those games and possibly add them to your repertoire games database. This allows you to see potential new ideas and how to play certain middle-games coming out of your repertoire.

**3. Hold the Draw** \- Take a drawn game and jump in and play it against the computer and try and hold the ending with 10-20 moves left. Try it from both sides, alternatively. This ii a great way to understand endgame play.

**4. Defend your King** \- this is the opposite of #1 - Take the losing position and try to defend it. You might want to consider reducing the +/- to a pawn down on the comp. valuation. This is good defensive practice when in a worse position.

Just some thoughts...

# Answer
Grandmaster Larry Christiansen recommends studying 200 recent games per week from games that relate to your opening repertiore. TWIC is ideally suited for doing that.
> 4 votes

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Tags: study
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title: Intervening with swiss pairing

text:
# Question
Title: Intervening with swiss pairing
In connection with the Hou Yifan incident in Gibraltar I read that when doing the pairings they avoided matches between players from Iran and Israel (for whatever reason...).

How is this technically done in a Swiss pairing system? Is there an option in the pairing program to set this? Algorithmically, is it done in such a way that these matches are considered played already (through some flag "playedAgainstEachOther=true") or in some other way?

# Answer
> 2 votes
> Is there an option in the pairing program to set this?

Of course.

Different approved Swiss pairing programs will do this is different ways. You should check out the User Manuals for the different programs to see how this is done.

For instance, in the Vega program go to the File menu, Round Manager, Avoid Pairs option and you can specify groups of players who should not be paired against each other for certain rounds. Generally speaking this should not be done in the last round where one of the players is on more than 50% even in the case of Iranian v Israeli since this can affect prizes and important placings.

> Algorithmically, is it done in such a way that these matches are considered played already (through some flag "playedAgainstEachOther=true") or in some other way?

This is a programming question rather than a chess question and does not belong here.

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Tags: rules, swiss-pairing
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# Question
Title: Alekhine's defence: Exchange variation 5.e5?
After a brief study over the exchange variation in the Alekhine's defence, On the fifth move Black can choose an extremely sharp line with e5 but i couldn't find it anywhere explained as either a bad or good move or even played.

# Answer
It's losing for Black because 6.c5 N(6)-d7 7. dxe! Black can't capture the pawn on e5 because 8. f4! wins a piece (e.g., 8. ... Nd7 9. Qe2+) so Black must play 7. Nxc5 and after 8. Bf4 White's pawn on d6 is a dagger in Black's heart. The chess engines say White is winning.
> 1 votes

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Tags: opening, alekhines-defense
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# Question
Title: Why do people say today's chess is dominated by computers?
Every time I read articles on chess I see people who say that chess is now dominated by computers. For example if you look for a thread on the subject 'Fischer vs Carlsen' (just an example) you see people comment that if Fischer had access to computers he would have been better. Why? What do modern GM's do with computers?

# Answer
Masters use computers as training tools. They allow a master to quickly check the viability of variations and understand why some moves are good or bad. Further, they afford searchable instant access to millions of positions and countless openings to the master.

In short, the computer is your sparring partner, second, and librarian, and who works for cheap.
> 11 votes

# Answer
All current chess players use computers to improve their game. This includes evaluating new positions in the opening resulting in better and deeper opening preparation. They also can set up a board and let the computer evaluate for hours to discover new lines that were previously too complicated to discover.

Also all chess players maintain huge databases of games, this they can search for games played by a specific player (particularly useful in matchplay) or search through historical games that contained a given position. Thus the use of computers is a vital tool to improve ones game especially when dealing with the "opening preparation".

An example of how new chess players are coming up - Hikaru Nakamura claims to have never read a single chess book and learnt completely off the computer.
> 7 votes

# Answer
Today, chess is dominated by computers, that's true because for the same calculating scale (ELO rating), we can compare ELO points of computers and ELO points of humans.

Today, the best ELO rating for a player (Magnus Carlsen): **2872** (february 2013).
Today, the best ELO rating for a computer (Houdini 3 64-bit 4CPU): **3320**.

Moreover, best chess players use chess engines to analyze positions. For instance, Viswanathan Anand currently use Houdini for training.
> 3 votes

# Answer
Computers allow unusual endgames to be solved much more quickly than a human can, if the human can do it at all. In Kasparov vs the World, the game ended with a 25-move forced checkmate discovered by computer.
> 0 votes

# Answer
Kasparov has said that computer + Grandmaster analysis is vastly superior than either computer or Grandmaster alone. I believe there was a chess league for a while that allowed strong programmer + player to compete one another along with strong chess computers or players alone. The combined players usually won tournaments. That's because the strong players can sense when a computer move is perhaps not the best long term strategic plan, although in the short term it is tactically justified.
> 0 votes

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Tags: engines
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# Question
Title: Who is the teacher of the game that has a lesson plan as follows:
To find the degree (or the number of attacked squares), of a square's corresponding vertex for all pieces and their corresponding graphs, given any square of the board. In other words, given a piece and a square - the number of attacked squares by the piece at the given square on an empty board is what the student finds. This is repeated until all squares are examined.

Also, has anyone had the idea to make a 3-D representation for each piece, where each square has a respective height equal to the degree of its' corresponding vertex in the given piece's graph (where the degree is the number of squares attacked by each specific piece at each square)? Of course, the rook's graph representation would be dull, as the graph is regular (ie the number of attacked squares is the same at any square), but all the other pieces, save for the pawn, would give students the visual lesson that the pieces in the center have more options. Not only this, it appeals to an old military adage - to control the high ground - which in these cases is the center, if at all possible.

# Answer
> 3 votes
Not in 3D and not super-fancy, but it should get across the point. I did not do it for the rook because as you note the rook always has 14 squares to go to (on an empty board).

However if you want to use this to argue for putting pieces in the center, I'd be careful, because:

* This is for an empty board. Lots of things can happen when other pieces are on the board.
* The illustration for the king is probably of limited value because (unless you are Steinitz) we don't usually think of the king as an active piece.
* For the queen and bishop (which are essentially the same, only shifted by 14, the number of rook moves) you notice that the difference between different squares (center and border) is not all that great. In my opinion a much more important factor for positioning queen and bishop centrally in a real game is that they have more options, i.e. a bishop in the center can go in four directions while a bishop in the corner has only one direction. This means that a bishop in the center can attack things in all four directions and likewise in order to block this bishop, the opponent has to block four directions. Also for transferring the bishop to other parts of a board a central position might be better.
* For the knight there could be some value in this as it cannot be blocked by other pieces, so the situation for a knight is essentially the same as on an empty board. That's where you get the saying: "A Knight on the rim is dim" from. But as with all such rules there are plenty of exceptions.

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Tags: teaching
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title: How can I tell when to sacrifice?

text:
# Question
Title: How can I tell when to sacrifice?
What are factors to consider when and when not to sacrifice? For example, imagine in a game where your opponent puts his bishop in direct sight of yours and you're not sure whether to take it or not? Is it safe to assume that one of the factors would be if your bishop is bad, then it might be a good idea to sacrifice it especially if the opponent has a good bishop?

# Answer
> 10 votes
What you describe would not be a sacrifice; it would be an exchange - bishop for bishop. And yes, if your bishop is bad (or generally unlikely to enter play without some time-consuming work), then it is a good idea to exchange, especially if your opponent's bishop is well-situated.

To address sacrificing - you should only sacrifice material if you gain a significant positional advantage by doing so, as in a well-played Greek gift sacrifice. Wikipedia's example fits here nicely: `1.e4 e6 2.d4 d5 3.Nc3 Nf6 4.e5 Nfd7 5.Nf3 Bb4 6.Bd3 O-O`:

Now White plays the sacrifice: `7.Bxh7+!` After taking the Bishop (`7... Kxh7`) Black is two points ahead, but severely exposed. White takes advantage of this by `8.Ng5+`, threatening `8...Kh8 9.Qh5+ Kg8 10.Qh7#`, which Black cannot avoid without losing his queen.

For another quick read on the topic of sacrificing, I would suggest *The Art of the Sacrifice*, written by an amateur only a couple months ago. It goes through the main points of sacrifices, along with profuse examples. Also, the ubiquitous Wikipedia is not to be missed.

Naturally, though, good chess reading costs money, so if you want some good, solid, on-your own instruction, you could consider purchasing some books on the subject.

# Answer
> 12 votes
Sacrifices have the following goals:

1. **exposing the king:** for example after your opponent castled, sacrificing the bishop to take the pawn diagonally to the king.
2. **cut the escape of the king:** this one is hard to explain, but basically after the sacrifice, if the opponent recaptures, the king can no longer occupy this square. Note that this can also happen even if there was an enemy piece originally, and you sacrificed by capturing it, but under the scenario that the new piece there have different mobility (e.g usually a knight) so after a check this new piece can't block it as opposed to the old piece.
3. **gaining (or making the opponent lose) tempos:** sometimes you find combinations that allows you to make important moves in time, or make the opponent lose time that he doesn't have. One example is if the two players are about to promote, but you sacrifice a piece so that the king blocks his own pawn or moves into a square that will be attacked by the promoted Queen (so when you promote you deliver a check).
4. **gain control of the center (or any other particular area):** this usually happens by sacrificing pawns from the flanks to be recaptured with enemy pawns from the center.
5. **weaken the pawn structure:** in very closed positions, these kind of sacrifices are almost always played. I can't give examples since I have never done one and usually don't understand them without computer analysis.
6. **removing of the defender (deflecting):** when a piece is the only one stopping the inevitably, it is usually worth taking it down no matter if you lose material.
7. **luring a piece to unwanted squares:** luring the king into forks, screws, etc. Another example is when a enemy bishop is preventing your pawns to advance, making him move out of that diagonal is deadly.

---

Some quick examples from one of my games:

```
[FEN ""]
1. e4  e5 2. Bc4  d6 3. Nf3  h6 4. O-O  Nf6 5. Nc3  Be7 6. d4  exd4 7. Qxd4  O-O 8. Be3  Nc6 9. Qd3  Bg4 10. Bxh6  gxh6 11. e5  Nxe5 12. Nxe5  dxe5 13. Qg6+  Kh8 14. Qxh6+  Kg8 15. Ne4  Be6 16. Rfe1  Bxc4 17. Nxf6+  Bxf6 18. Re3  Bg5 19. Rg3  f6 20. Qg6+  Kh8 21. Rh3+ 1-0

```

**(#1)** \- `10.Bxh6` might not be the best move from that position, but it is not a bad one either, there is a very dangerous pin by the white bishop that together with the Queen can do amazing things. The main idea is to expose the enemy king.

**(#3 and #6)** \- `11.e5` if the Knight moved, I would have achieved #6 over the bishop, however he didn't and decided to take the pawn, I didn't care which way he take the pawn, my #3 is achieved since all I wanted to free the Queen diagonal.

**(#6)** \- `15.Ne4` I attempted to remove the defender of the bishop, with the plan of capturing the bishop with this line `15.Ne4 Nxe4 16.Qg6+`

**(#3)** \- `16.Rfe1` is also interesting, some people would say it is not a direct sacrifice though, but it is deliberately not protecting a piece. The main idea is to don't waste any time and activate the rook ASAP, while still having a chance to protect the other piece if he decides to go for NxN first.

# Answer
> 5 votes
A good time to "sacrifice" is when the true value of the piece you are getting is worth more than the value of the piece your are giving up, even though your piece has a greater *nominal* value.

Examples: 1) You (White) have a rook on an open f-file, and your opponent has a knight on f6. You play `RxN`, Black retakes with his pawn at g7: `...gxf6`. Two things have happened. Black has lost a major defensive piece on the kingside, and lost pawn protection on the g file. Even though you have "lost the exchange," what you have gotten is well worth a rook. 2) In another scenario, you might move `Nf5` to coax `...gxf5` from the pawn on g6. You recapture, having traded a knight for a valuable pawn that no longer protects the enemy king.

Generally, you sacrifice in an area, usually the kingside, where you have preponderance of force. If you have four pieces to one, or five to two, you sacrifice one for one or two for two, even if your pieces have greater nominal value (sometimes a rook or queen for a minor piece). Then your remaining pieces crush the enemy king.

# Answer
> 2 votes
"Material" is but one of the types of advantages in chess. However, it is the easiest one for most people to understand.

Other types of advantages: space, piece activity, king safety.

You learn how to spot good sacrifices when you become more aware of the *other forms of advantage* in chess. Sacrificing is merely taking a hit on the material score in order to gain an advantage in another area.

These words will be easily forgotten without examples. The best examples are classic games. \[The games of modern players are not as good because their defensive technique is so good that sacrifices rarely work against them.\]

Don't wait for people to teach you in this thread - start learning with a google search or two. Here's one on Great sacrifices in chess.

https://www.google.com/search?q=great+sacrifices+in+chess&ie=utf-8&oe=utf-8

Go over the many games there and learn from them. See if you can get a sense as to what *compensatory advantages* are gained for the sacrificed material.

# Answer
> 0 votes
Most of the examples presented in the other answers are about sacrifices related to tactics, i.e. you give up material for a clear purpose; to mate the enemy king or to gain back the material (and more) soon. While these are certainly valid sacrifices they don't happen all that often in high level chess, because everybody is doing their best to not allow them.

Much more common at those levels are positional sacrifices, where you give up material in order to gain a long-term positional advantage or even just to unbalance the position. Most common are pawn and exchange (you give a rook for a bishop or knight) sacrifices.

Typically exchange sacrifices happen in rather closed positions where the rooks are not that powerful and often the captured knight/bishop was a very valuable piece (for defense or attack).

Pawn sacrifices are often done to spoil the opponent's pawn structure or coordination of pieces.

As an example this very nice positional queen sacrifice by Caruana. Look at the position around move 21. Black is completely dominated on the light squares. While it is not clear how black will lose it is a pretty hopeless position.

```
[Event "London Chess Classic"]
[Site "London ENG"]
[Date "2016.12.15"]
[EventDate "2016.12.09"]
[Round "6.3"]
[Result "1-0"]
[White "Fabiano Caruana"]
[Black "Hikaru Nakamura"]
[ECO "B96"]
[WhiteElo "2823"]
[BlackElo "2779"]
[PlyCount "63"]
[FEN ""]

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6 5. Nc3 a6 6. Bg5 e6
7. f4 h6 8. Bh4 Qb6 9. a3 Be7 10. Bf2 Qc7 11. Qf3 Nbd7
12. O-O-O b5 13. g4 g5 14. h4 gxf4 15. Be2 b4 16. axb4 Ne5
17. Qxf4 Nexg4 18. Bxg4 e5 19. Qxf6 Bxf6 20. Nd5 Qd8 21. Nf5
Rb8 22. Nxf6+ Qxf6 23. Rxd6 Be6 24. Rhd1 O-O 25. h5 Qg5+
26. Be3 Qf6 27. Nxh6+ Kh8 28. Bf5 Qe7 29. b5 Qe8 30. Nxf7+
Rxf7 31. Rxe6 Qxb5 32. Rh6+ 1-0

```

# Answer
> -1 votes
Measurable gain is not a sacrifice.

There is a percentage of physical and before so don't hesitate, which capacity is been already accumulate for gain....

---
Tags: sacrifice
---


title: ECO D00 Game for Analysis

text:
# Question
Title: ECO D00 Game for Analysis
After long time, I had played ECO D00,- 1.d4 d5 2.e3 . As my precision lags, I was not yet well with Queens Gambit Accepted or Declined variation. For this position 1.d4 d5 2.e3 my Android Chess.com App says Stonewall Attack, I am not much aware what does that first of all, when I checked, its all are different in WIKI for `Stonewall Attack`.

Here I have the complete game embedded for further analysis. I would like to know abt. PIN in this game. Is that arisen because inaccurate moves considering positioning powers or pawn.

Other than PIN I would like general analysis & reviews. Thanks!

Here is the game and PGN,

```
[fen ""]
[Event "Live Chess"]
[Site "Chess.com"]
[Date "2017.02.01"]
[Round "?"]
[White "anandsadasivam"]
[Black "Tudorache951"]
[Result "1-0"]
[ECO "D00"]
[WhiteElo "756"]
[BlackElo "714"]
[TimeControl "600"]
[Termination "anandsadasivam won by checkmate"]
[CurrentPosition "5BQ1/8/3N3R/8/8/3K4/5P1k/8 b - - 4 55"]

1.d4 d5 2.e3 Nc6 3.Qf3 { (+0.37 → -0.81) Inaccuracy. A better move was 3. Nf3. } ( 3.Nf3 e6 4.Be2 Bd6 5.c4 Nf6 6.Bd2 O-O 7.Nc3 b6 ) 3...Nb4 { (-1.00 → -0.16) Inaccuracy. A better move was 3... Nf6. } ( 3...Nf6 4.h3 e5 5.Bb5 Bd6 6.Bxc6+ bxc6 7.Qg3 O-O 8.dxe5 ) 4.Bd3 g6 5.Nh3 { (-0.30 → -0.94) Inaccuracy. A better move was 5. Qe2. } ( 5.Qe2 Nf6 6.Nf3 Nxd3+ 7.cxd3 Bg4 8.Nc3 Bg7 9.O-O O-O ) 5...h6 { (-1.00 → -0.29) Inaccuracy. A better move was 5... Nf6. } ( 5...Nf6 6.Nc3 Bg4 7.Qf4 e6 8.Nb5 Nxd3+ 9.cxd3 Bd6 10.Nxd6+ ) 6.Na3 { (-0.38 → -1.21) Inaccuracy. A better move was 6. Nf4. } ( 6.Nf4 Nf6 7.h3 Nxd3+ 8.Nxd3 Bg7 9.Nc3 Bf5 10.O-O O-O ) 6...Bf5 { (-0.99 → +0.78) Mistake. The best move was 6... Nf6. } ( 6...Nf6 7.Bd2 ) 7.e4 { (+0.82 → -0.52) Mistake. The best move was 7. Bxf5. } ( 7.Bxf5 gxf5 8.Qxf5 Nf6 9.Qf3 e6 10.O-O Rg8 11.Nf4 Bd6 ) 7...Be6 { (-0.20 → +1.05) Inaccuracy. A better move was 7... Nxd3+. } ( 7...Nxd3+ 8.cxd3 ) 8.e5 { (+0.88 → -0.01) Inaccuracy. A better move was 8. Nf4. } ( 8.Nf4 Nxd3+ 9.Qxd3 dxe4 10.Qxe4 Nf6 11.Qxb7 Bd5 12.Nxd5 Qxd5 ) 8...f6 { (+0.23 → +10.58) Blunder. The best move was 8... Nxd3+. } ( 8...Nxd3+ 9.Qxd3 c6 10.Nf4 Bf5 11.Qe2 h5 12.O-O e6 13.Nd3 ) 9.exf6 { (+10.68 → +0.43) Blunder. The best move was 9. Bxg6+. } ( 9.Bxg6+ Bf7 ) 9...Nxf6 { (+0.56 → +3.46) Blunder. The best move was 9... Nxd3+. } ( 9...Nxd3+ 10.Qxd3 ) 10.Nf4 { (+3.28 → +0.36) Blunder. The best move was 10. Bxg6+. } ( 10.Bxg6+ Kd7 11.Nf4 Bg4 12.Qb3 e6 13.f3 Bf5 14.Bxf5 exf5 ) 10...Bg4 { (+0.33 → +2.81) Mistake. The best move was 10... Nxd3+. } ( 10...Nxd3+ 11.Qxd3 Bf5 12.Qb5+ c6 13.Qxb7 Qc8 14.Qb3 Rb8 15.Qe3 ) 11.Qe2 { (+2.74 → -4.24) Blunder. From winning to losing. The best move was 11. Bxg6+. } ( 11.Bxg6+ Kd7 ) 11...Bxe2 12.Kxe2 Ng4 { (-7.22 → -1.70) Blunder. The best move was 12... Nxd3. } ( 12...Nxd3 13.Nxd3 e6 14.h4 Kf7 15.Bf4 Bd6 16.Be5 c6 17.c3 ) 13.h3 { (-2.16 → -6.32) Mistake. The best move was 13. Bxg6+. } ( 13.Bxg6+ Kd7 14.Bf5+ e6 15.Bxe6+ Kc6 16.Bxg4 Bd6 17.g3 Qf6 ) 13...Nf6 { (-6.89 → -3.22) Blunder. The best move was 13... Nxd3. } ( 13...Nxd3 14.Nxd3 Nf6 15.Bf4 c6 16.c3 Qb6 17.f3 Qa6 18.Kd2 ) 14.Bxg6+ Kd7 15.Re1 e6 16.Kf1 Rg8 { (-3.79 → -2.51) Inaccuracy. A better move was 16... Ne4. } ( 16...Ne4 17.c3 Nc6 18.Bf7 Ng5 19.Nxe6 Qf6 20.Nxg5 hxg5 21.Be6+ ) 17.Bd3 { (-2.64 → -5.68) Mistake. The best move was 17. Nxe6. } ( 17.Nxe6 Rxg6 18.Nxd8 Rxd8 19.f3 Bd6 20.g4 Rf8 21.Kg2 c6 ) 17...Nxd3 18.cxd3 Nh5 { (-6.44 → -4.54) Inaccuracy. A better move was 18... c6. } ( 18...c6 19.Nxe6 ) 19.Nxe6 { (-4.70 → -8.49) Inaccuracy. A better move was 19. Nxh5. } ( 19.Nxh5 Qh4 20.Nf4 Bd6 21.g3 Rxg3 22.fxg3 Qxg3 23.Ke2 Bxf4 ) 19...Qe7 { (-8.55 → -0.04) Blunder. The best move was 19... Qf6. } ( 19...Qf6 20.Re5 ) 20.Nc5+ Kd6 { (-0.02 → +1.02) Inaccuracy. A better move was 20... Kc6. } ( 20...Kc6 21.Rxe7 ) 21.Rxe7 Bxe7 22.Bxh6 { (+1.13 → +0.34) Inaccuracy. A better move was 22. g4. } ( 22.g4 Nf6 23.Bf4+ Kc6 24.Rc1 Rac8 25.Be5 Ne8 26.Nc2 Bxc5 ) 22...Rae8 { (+0.12 → +2.33) Mistake. The best move was 22... b6. } ( 22...b6 23.Na6 c6 24.Rc1 Kd7 25.Nc2 Rg6 26.Bd2 Rf8 27.Ne3 ) 23.Nxb7+ { (+2.31 → +1.03) Mistake. The best move was 23. g4. } ( 23.g4 Rh8 24.Bd2 Kc6 25.Rc1 Nf6 26.g5 Rxh3 27.Na6+ Kb6 ) 23...Kc6 24.Nc5 Bxc5 25.dxc5 Kxc5 26.Rc1+ Kd6 { (+1.71 → +3.83) Mistake. The best move was 26... Kb6. } ( 26...Kb6 27.Nc2 Kb7 28.g4 Ng7 29.Nb4 Ne6 30.Kg2 Rh8 31.Bd2 ) 27.Nb5+ Kd7 { (+3.27 → +5.02) Inaccuracy. A better move was 27... Ke7. } ( 27...Ke7 28.Rxc7+ Kf6 29.Bd2 Re7 30.Bc3+ Kf7 31.Nd6+ Ke6 32.Rc6 ) 28.Nxa7 { (+4.62 → +0.88) Blunder. The best move was 28. Rxc7+. } ( 28.Rxc7+ Kd8 29.Rxa7 Rg6 30.Bd2 Re7 31.Ra8+ Kd7 32.Nd4 Rf7 ) 28...Rg6 29.Be3 { (+0.50 → -0.29) Inaccuracy. A better move was 29. Bd2. } ( 29.Bd2 Rb6 30.b4 Ra8 31.Rc5 Rxa7 32.Rxd5+ Rd6 33.Rxh5 Rxa2 ) 29...Rf8 { (-0.67 → +1.70) Blunder. The best move was 29... Ng3+. } ( 29...Ng3+ 30.fxg3 ) 30.Nb5 c6 31.Nd4 c5 { (+1.80 → +3.42) Inaccuracy. A better move was 31... Nf4. } ( 31...Nf4 32.Bxf4 Rxf4 33.Ne2 Ra4 34.a3 Rg8 35.Rc2 Rb8 36.g4 ) 32.Rxc5 Kd6 { (+3.79 → +9.60) Mistake. The best move was 32... Nf4. } ( 32...Nf4 33.Bxf4 ) 33.Nf5+ { (+9.86 → +0.14) Blunder. The best move was 33. Rc6+. } ( 33.Rc6+ Kd7 34.Rxg6 Nf4 35.Rg5 Kd6 36.Rf5 Rxf5 37.Nxf5+ Ke5 ) 33...Ke6 { (+0.07 → +6.10) Blunder. The best move was 33... Rxf5. } ( 33...Rxf5 34.Ra5 Ke5 35.g4 Ng3+ 36.Kg2 Ne2 37.Kf1 Ng3+ 38.Kg2 ) 34.Nd4+ { (+6.34 → +4.59) Inaccuracy. A better move was 34. g4. } ( 34.g4 Nf6 35.Rc6+ Kd7 36.Ra6 Rgg8 37.Ra7+ Kc6 38.Ne7+ Kd6 ) 34...Kd6 { (+4.58 → +10.25) Mistake. The best move was 34... Ke7. } ( 34...Ke7 35.g4 Ng7 36.Rxd5 Ra8 37.a3 Kf7 38.Kg2 Raa6 39.Kg3 ) 35.Nb5+ { (+10.39 → +4.14) Blunder. The best move was 35. Rc6+. } ( 35.Rc6+ Kd7 36.Rxg6 Nf4 37.Rg5 Nxd3 38.Rxd5+ Kc8 39.b3 Nb4 ) 35...Kd7 { (+3.97 → +7.89) Inaccuracy. A better move was 35... Ke6. } ( 35...Ke6 36.Nc7+ Kd6 37.Rc2 Nf4 38.Bc5+ Kxc7 39.Bxf8+ Kd7 40.f3 ) 36.Rc7+ { (+8.08 → +3.99) Blunder. The best move was 36. Rxd5+. } ( 36.Rxd5+ Ke6 37.Rxh5 Rd8 38.Bd4 Rc8 39.g4 Rc1+ 40.Ke2 Kf7 ) 36...Ke8 37.Bc5 Nf4 { (+4.65 → +7.01) Inaccuracy. A better move was 37... Rff6. } ( 37...Rff6 38.Re7+ Kd8 39.Re5 Nf4 40.Be7+ Kd7 41.Bxf6 Rxf6 42.a4 ) 38.Rc8+ Kf7 { (+7.39 → +14.41) Inaccuracy. A better move was 38... Kd7. } ( 38...Kd7 39.Rxf8 Ne6 40.Ba3 Nxf8 41.Bxf8 Ra6 42.a3 Rc6 43.Bg7 ) 39.Rxf8+ Kg7 40.Rxf4 Rc6 41.Bf8+ Kg6 { (+14.83 → +51.78) Inaccuracy. A better move was 41... Kg8. } ( 41...Kg8 42.Nc3 ) 42.h4 { (+53.21 → +13.48) Mistake. The best move was 42. Nc3. } ( 42.Nc3 Ra6 43.Nxd5 Ra5 44.Ne7+ Kg5 45.b4 Rb5 46.a4 Kxf4 ) 42...Rc1+ 43.Ke2 Rc2+ 44.Kf3 Rxb2 45.Nd6 Rxa2 46.g4 Ra3 47.Ke3 { (+58.08 → +18.77) Inaccuracy. A better move was 47. h5+. } ( 47.h5+ Kh7 48.Ke3 Ra8 49.g5 Rd8 50.Be7 Rd7 ) 47...d4+ 48.Kxd4 { (+33.15 → +16.17) Inaccuracy. A better move was 48. Ke4. } ( 48.Ke4 Ra7 49.h5+ Kg5 50.Nf7+ Kh4 51.h6 Kh3 52.h7 Kg2 ) 48...Rxd3+ { (+25.38 → +318.00) Mistake. The best move was 48... Rb3. } ( 48...Rb3 49.h5+ ) 49.Kxd3 Kh7 50.g5 { (Mate in 4 → Mate in 4) Excellent. Faster mate A better move was 50. Nf5. } ( 50.Nf5 Kg8 51.Ne7+ Kh8 52.Rf5 Kh7 53.Rh5# ) 50...Kg6 51.Rf6+ { (Mate in 5 → Mate in 5) Excellent. Faster mate A better move was 51. Ke4. } ( 51.Ke4 Kh7 52.h5 Kh8 53.g6 Kg8 54.Bh6 Kh8 55.Rf8# ) 51...Kh5 52.g6 Kxh4 53.g7 Kh3 54.g8=Q Kh2 55.Rh6#  1-0

```

Here is the fen,

```
[fen "5BQ1/8/3N3R/8/8/3K4/5P1k/8 b - - 4 55"]

```

# Answer
> 1 votes
Stonewall attack refers to a pawn structure with pawns on f4, e3 and d4. If you don't play f4, it should not be called stonewall. If you want to give it a name you could call it closed "Queen's pawn game". In any case looking at this game you should not worry about opening at all, but first and foremost focus on not blundering pieces in one move (and so should your opponent).

> I would like to know abt. PIN in this game.

Do you mean a pin? At which move do you see a pin?

Analysis/comments:

* 3. Qf3 Getting out the queen early makes her prone to attack. Develop your minor pieces (bishop, knight) first. Also on f3 the queen does not do much and takes away that square for development of the knight.
* 5. Nh3 and 6. Na3 You really like putting the knights on the rim, do you? Usually it is better to develop knights towards the center (via c3, f3, d2 or e2) where they have more space and can attack things)
* 7. e4 Here you could have won a pawn after 7 Bxf5 gxf5 8. Qxf5 (tactical motif: *counting*)
* Starting from move 9. you could just take the pawn on g6 with check
* 11. Qe2?? It is good that you realized that your queen was attacked but you should have removed her to somewhere safe like e3 or g3. Also you could still have captured Bxg6+ with check and only after that removed your queen.
* 19. Nxh5 would give you a knight for free
* 20 Nc5+ and 21 Rxe7 Well spotted that you can win the queen!
* 33 Rc6+ (*skewer*) would win the rook on g6; 33 Nf5+?? this knight could just be taken by black 33. ... Rxf5
* 35 Nb5+? Missed your second chance to play 35 Rc6+ winning the rook on g6

Your question suggests that you are concerned about opening theory, which you really should not at this level. During the game you and your opponent blundered like 5 pieces each and whether you play queen's gambit or stonewall attack or whatnot is completely irrelevant in this case.

Most important for you would be to concentrate on not blundering pieces and also to take pieces when allowed to. So at every move check whether something is attacked and whether you attack something which you can capture. Also before making a move make sure that after the move you don't lose material. There are two ways to do this, you can go through the whole board each and every time to look for these things or you can do this incrementally, meaning to look for changes in the position. What I mean by this is that if say your opponent makes a move this will only affect some part of the board, so you only need to look for any changes in that part (and keep in mind all the other potential options which did not change).

Once you blunder fewer pieces you can start studying basic tactics like pin, skewer, double attack (knight and pawn forks) and improve on your strategy, which is not all that bad (for a player at your level), except for somewhat neglecting development of pieces.

Only then should you think of opening theory.

---
Tags: opening, analysis, learning
---


title: Is there an Android chess GUI library

text:
# Question
Title: Is there an Android chess GUI library
I am looking for an open source chess gui library for Android that I can use in an app so that I don't need to take care of the GUI engine, but can focus on the logic behind it.

I have searched for solutions but not found anything. Does something like this exist?

# Answer
You can use mine. I have an Android application that takes care of the GUI elements.

https://github.com/jj30/ChessPGNHelper

The application itself is in the play store at

https://play.google.com/store/apps/details?id=bldg5.jj.pgnbase

Please attribute me (Jan Jansz) as a developer where possible. (I need it; thanks.)
> 3 votes

# Answer
I don't see anything better than the active Droidfish app.
> 1 votes

---
Tags: programming, android, open-source
---


# Question
Title: Which piece is least likely to be taken?
If one were to analyse a large number of chess games, which specific piece (not *type* of piece) would be found to be taken the least number of times? And yes, in light of SomePatzer's comment, besides the kings of course.

# Answer
> 13 votes
I recently looked into that very thing a couple of weeks ago, and found an excellent breakdown on it (*just this one, though*):

The short answer is that aside from Kings, h2 & h7 are the least likely to be captured pieces (*with survival rates claimed to be 73.92% and 72.29%, respectively*).

Regarding individual pieces' survival (*from a 2,196,968 game database*), http://www.quora.com/What-are-the-chances-of-survival-of-individual-chess-pieces-in-average-games/answer/Oliver-Brennan gives a table (*and an accompanying graphic*) of each piece's respective chance of survival.

---

While I was at it, I found some data on square usage. I've included the sources below not because square usage relates to your question directly, but because the nature of the two topics is so close that I figured that they might be of interest to you (*or future readers*).

Using 509 games selected randomly \[and analyzed\] out of a 567,000 game database, these two URLs give tables of raw events and normalized through-traffic usage of squares, and heat maps of same:

1. http://sarcasticresonance.wordpress.com/2010/10/05/chess-territorial-2
2. http://sarcasticresonance.wordpress.com/2010/10/13/random-chess-conquests/

This URL analyzes the moves of 12 Grandmasters' entire careers (*separated by white and black, all normalized \[no raw counts\]*), along with some graphs of average-data counts:

1. http://en.chessbase.com/post/seth-kadish-visualizing-chess
2. http://en.chessbase.com/post/study-of-square-utilization-and-occupancy

There are also some excellent analyses (*per side*) of each type-of-piece's square usage at http://philanalytics.blogspot.com/2014/11/chess-analytics-analyzing-championship.html .

# Answer
> 4 votes
Probably the rooks. That's why the greatest number of endings are the rook endings.

The knights and bishops fight it out early on and get "killed." Later, the queens are targets because they're so powerful, and they get traded. The rooks are left on the board. Sometimes one or both sets are traded, but often, they remain until one player resigns.

Between the rooks, the queen rook is less exposed, and therefore less likely to be captured.

# Answer
> 1 votes
The obvious answer is the king. It will be taken 0 times. The most frequent one would be a pawn: there are 16 pawns and you can hardly find a game, where a pawn is not taken. I would bet that the least frequently taken (apart from king) would be a queen.

I do not have statistics to back up my assertion, but you have only 2 queens and 4 rooks, bishops, knights. Also pro players prefer not to exchange queens early, so they will go only after some of the other pieces would be exchanged.

# Answer
> 1 votes
The h2/h7 pawns as confirmed by @Charles Rockafellor seems to be the most likely to me; at least for normal games above Patzer level.

If you look at games there are very few pawnless end positions. And since more people castle short than long, it makes sense to keep those protective f-g-h pawns a bit longer. Also the h pawns being where they are at the rim, it is very hard to get at them and if they'd ever be involved in some exchange action it could only be to one side, towards the g file.

# Answer
> 0 votes
If by taken, you mean captured, then the least likely to be taken might be the queen, although it's impossible to statistically prove it as there are as many possible chess games as atoms in the universe.

By taken, if you consider an exchange, I would bet on the rooks.

---
Tags: statistics, captures
---


title: Trying to locate an old problem

text:
# Question
Title: Trying to locate an old problem
A friend of mine showed me a great white-to-mate-in-three puzzle back in the late '50s or early '60s. Unfortunately he doesn't recall it. I can remember a few things: It was composed by someone from West Virginia. White had two knights at opposite corners of a 3x3 block. White's first move was not a check. Can anyone help me find it?

# Answer
> 3 votes
This is hit or miss.

No one can really know what puzzle your thinking about, so please don't down vote wrong attempts. People shouldn't be penalized for trying to help. It's only through trial and error we're going to help you find your puzzle.

Is this your puzzle: HERE?

---
Tags: problems, identify-this
---


# Question
Title: Connecting Chess Engine with a Java program
I wanted to make a 1 player chess game.

The idea is:

* The move made by the player would be displayed on the GUI.
* It is sent to the Chess Engine in its own specific understood form.
* Then the result of the Chess engine would be taken and then made visible on the GUI.

Currently I have made no progress on it and am on a dead end. My current program on Java lets 2 players play with each other. The program manages the rules that have to be followed and which moves are illegal. But for a single player game I wanted an AI for my game that can take inputs and give outputs. I searched online for various open source chess engines like Stockfish. But found nothing about using it in my program.

I tried to work on to create my own engine but it was quite a challenge for me. Hence connecting it with an external AI is the only solution I think there is.

# Answer
> 9 votes
Let's break it down:

* You have a working Java chess board that you can use to move pieces
* You want a chess engine (**engine** is a more precise term than **AI**)
* You want to download Stockfish and use it
* You want to invent a new protocol or technology to communicate your chess board with the Stockfish engine

To me, your question is really:

* How to connect an external chess engine such as Stockfish within my own chess GUI in Java?

Useful old posts in this site:

Basically, what you need to do is:

1. You shouldn't invent your own technology, you should study the UCI protocol. http://wbec-ridderkerk.nl/html/UCIProtocol.html is a useful reference. I can get you started, do this:

1. Download Stockfish
    2. Open Stockfish in a console/terminal, don't double-click on it with your mouse
    3. Type `ucinewgame` and then `go movetime 1000`. Do you see Stockfish's move?
    4. Read the protocol specification and learn how to analyze a position, and the output format.
2. Write a UCI output parser. Parse whatever information you want.
3. Use the information to make a move on your chess board.

The only technical difficulty I can see here is to establish a "connection" between your GUI with the engine. This is done by creating a new process, running the engine.

> https://stackoverflow.com/questions/2006035/how-to-create-a-process-in-java has information on how to do it.

Once you have the new process, you can establish a simple standard input/output pipeline. https://stackoverflow.com/questions/27081918/java-how-to-send-a-value-to-child-process-using-outputstream has the details. Ask on Stackoverflow if you're not sure.

---
Tags: engines, software, stockfish
---


# Question
Title: beginner chess terminology: opening is white's and defense is black's?
absolute beginning self-learner here, asking trivial terminology:
xyz(*placeholder*) **opening** is speaking of **white**'s play and zyx(*placeholder*) **defense** is referring to **black**'s play, is that correct?
or
opening schemes are played by white, while defense schemes are played by opponent -- the black.
Is this thinking correct?

# Answer
> 5 votes
I believe that there is not much meaning in these terms and the terminology developed historically. Terms like *opening, defense, attack, game,...* are often used synonymously.

**Opening** is the general term which can be used to refer to any sequence of moves at the start of the game.

Also it refers to systems that develop after 1. e4 e5 (e.g. Italian, Spanish openings) which a long time ago were by far the most popular and considered the best because they follow the straightforward plan of occupying the center and developing pieces to active positions.

Later, other openings were developed which do not follow such a natural plan. E.g. in those new openings white is often allowed to create a strong pawn center which black later attacks. Many of these received the name **defense**, perhaps to signify that black is not going for active play immediately but lets white get somewhat active. Examples are the French, Sicilian, Caro-Kan, King's Indian,... defense.

However note that in these defenses it is black who determines the structure of the game to a large extend, by deciding e.g. between the French or the Sicilian which result in completely different kind of games. In the Spanish/Italian on the other hand it is white who makes the major decision on the third move, between 3. Bc4 and 3. Bb5.

Then there are also the **attacks** (e.g. King's Indian attack) which often refer to color-reversed defenses. In these it is mostly white who decides the structure.

Generally (with a few exceptions, usually called "system" or "set-up" such as the Colle system), black's and white's moves in openings are related. So it does generally not make sense to talk about an opening for one side only. For instance the King's Indian is basically defined by a certain set-up for black: (pawns on d6, e5, g6, bishop on g7, short castle, later play f5 and attack on the king side). But still experience has shown that there is a recommended way for white to play against it and therefore King's Indian means both, the black and the white set-up.

But as mentioned, don't break your head over this. Just take it as a name without much meaning. In the same way there is not much meaning in "open", "semi-open", "closed" openings. For instance you can have very closed positional play in some lines of the Spanish/Ruy-Lopez which would be classified as "open".

If you are a beginner focus on general opening principles and tactics. This will be more useful than learning a specific opening.

---
Tags: terminology
---


title: multi PVs using triangular array

text:
# Question
Title: multi PVs using triangular array
I am currently using a triangular array to collect the PV in my chess engine (written in C). However, I would like to return several variations such as the second best, third best, and so fourth. Is is possible to do with a triangular array scheme or do I need to use a transposition table. In either case is there a simple example of an engine that uses; one preferably in C?

# Answer
You use neither.

You run your search to collect the best PV from your triangular table. This gives you your best variation. Then you exclude this best move and run another search to get the best PV from your triangular table. This gives you your second best variation. And so on.
> 0 votes

---
Tags: engines, transpositions
---


# Question
Title: How do I make my opening reportorie stronger, specifically my Grand Prix Attack against high level competition?
I saw the DVD Killer Grand Prix Attack from GM Gawain Jones. This helped a lot. However, I have some trouble with some concepts against 2 ...e6 lines. According to the DVD the second plan of the Grand Prix Attack is to play Bb5 and capture the Nc6 to give Black double c pawns then attack the double pawns in a positional way. However, I sometimes heard you have to transition to Closed Sicilian or Open. Here is an example were I'm unsure.

1. e4 c5
2. Nc3 e6
3. f4 Nc6
4. Nf3 d6
5. Bb5 Nge7
6. o-o g6
7. d3

Would it better to play Bb5 earlier to go for the double pawn plan or 5. Bb5 here is better such as this game was played? Would 7. d4 be better than 7. d3?

What are further resources to study the Grand Prix Attack seriously?

# Answer
As resource:

Please check Lawrence Trent's analysis from White's perspective and Andrew Martin's's from Black's perspective.

About line:

I don't find it correct to say anything about this line without studying state-of-the-art. So, you better check experts analyses for suggestions.
> 2 votes

# Answer
A strong player is going to know how to get a good position against an opening like this that is considering weak. Theory and computers suggest your position favors Black. There have been 29 master level games played from this position with Black winning the majority of them.

That said, after Bg7, White should play Qe1. Below is a sample game. 12. Qe4 was the losing move but the best move was the embarrassing retreat 12.Qe1.

\[Event "Ch England"\] \[Site "England"\] \[Date "2015.3.22"\] \[Round "8"\] \[White "Dean Michael (ENG)"\] \[Black "Levy Christopher A (ENG)"\] \[Result "0-1"\] \[Eco "B23"\]

1.e4 c5 2.Nc3 Nc6 3.f4 e6 4.Nf3 d6 5.Bb5 Nge7 6.O-O g6 7.d3 Bg7 8.Qe1 h6 9.Qh4 Bd7 10.f5 exf5 11.exf5 g5 12.Qe4 Bxf5 13.Bxc6+ bxc6 14.Qa4 O-O 15.Be3 Be6 16.Rae1 Qd7 17.Ne2 Nf5 18.Bd2 d5 19.d4 cxd4 20.Nexd4 Nxd4 21.Nxd4 c5 22.Qxd7 Bxd7 23.Nf5 Bxf5 24.Rxf5 Rad8 25.Ba5 Rd7 26.c4 Bd4+ 27.Kf1 dxc4 28.Bc3 Rb8 29.Rd1 Rdb7 30.Rd5 Bxc3 31.bxc3 Rb1 32.Kf2 Rxd1 33.Rxd1 Rb2+ 34.Kf3 Rc2 35.Rd8+ Kg7 36.Rc8 Rxc3+ 37.Ke4 Rc2 38.Kf3 Rxa2 39.Rxc5 Ra3+ 40.Ke2 c3 41.Kd3 Ra2 42.Rxc3 Rxg2 43.h3 Rg3+ 44.Kc4 0-1
> 0 votes

---
Tags: opening, analysis, learning, theory
---


# Question
Title: Why is 4...e5 not popular in the Smith-Morra Gambit?
When I encounter the `Sicilian` as White, I often will play the `Smith-Morra Gambit`. My opponent played `4...e5`, but this does not appear to be a very popular move as there are only 2 games on www.chessgames.com that have it, one of them being here, which is apparently the first ever `Smith-Morra Gambit` recorded. I didn't even see Wikipedia give it as an option, so I was curious to know why `4...e5` is not popular or in other words, what drawbacks does it have?

```
[FEN ""]
1. e4 c5 2. d4 cxd4 3. c3 dxc3 4. Nxc3 e5

```

# Answer
I could not find any master games which included `4. ... e5`. Of the amateur games I found, the move produced the worst '%age win' result for Black of all moves listed. (Black's best response? `4. Nf6`, being prepared to retreat it back to `g8` if White pushes the e pawn. How the Hypermodernists would grin. These are all amateur games, remember... so you'll have to do your own analysis.)

I see almost 80 games that include `4. ... e5`. White's wins about 70% of the time which is huge. Black's win percentage just under 21%. The only responses recorded for White are `5. Bc4` and `5. Nf3` with the former being marginally more successful.

Here are some sample games.

This one is Erich Hoffman v Walter Geissler from the 2005 EU-ch Seniors. ECO B21.

```

[fen ""]
1. e4 c5 2. d4 cxd4 3. c3 dxc3 4. Nxc3 e5 5. Bc4 Nf6 6. Qb3 d5 7. exd5 Bd6 8.  Bg5 h6 9. Bh4 g5 10. Bg3 a6 11. h4 g4 12. h5 Nbd7 13. Bh4 Qc7 14. Bg3 Nb6 15.  Be2 Bd7 16. Rd1 Rg8 17. Bd3 Qc5 18. Bb1 Qa5 19. Kf1 Rb8 20. Nge2 Rg5 21. Bh4  Rxh5 22. Ng3 Rxh4 23. Rxh4 Nfxd5 24. Nge4 Bf8 25. Nxd5 Bb5+ 26. Kg1 Nxd5 27.  Qxd5 Be7 28. Rxh6 1-0

```

The first thing that strikes me is White's 9th move, a uncomfortable attack on two of Black's weakest squares, `b7` and `f7`. Now Black's backward `d` pawn is a liability as he can't easily block the `a2-g8` diagonal. Black is forced to give the pawn back. That being said, I don't see White getting any real traction here. If Black castled on move 10 instead of playing `g5` he'd have had even chances. The path he chooses instead leads to a back-rank weakness that ends the game. Stockfish wasn't impressed with the entire adventure between Black's `g` pawn and h-file Rook, or White's Bishop and `h` pawn. While both players miss some chances for improving their positions, Black's shattered King-side pawns remain. The game is back and forth from moves 13 to 22; either player could have gained an advantage. However Black's `23. ... Nfxd5` is tragic and ends Black's chances to survive. After that he comes apart.

This one is Ondrej Gabris v Ladislav Kasas from SVK-chT1W 0405. ECO B21. Both are rated between FIDE(?) 2050 and 2100 so these players are similar in strength to USCF Masters. I'll post it without any Stockfish analysis as I am out of time.

```

[fen ""]
1. e4 c5 2. d4 cxd4 3. c3 dxc3 4. Nxc3 e5 5. Bc4 Nf6 6. Qb3 d5 7. exd5 Bd6 8.  Bg5 h6 9. Bb5+ Nbd7 10. Bxf6 Qxf6 11. Nf3 O-O 12. Ne4 Qe7 13. O-O Nf6 14. Nxf6+  Qxf6 15. Nd2 Bf5 16. Bd3 b6 17. Rfe1 Bc5 18. Bxf5 Qxf5 19. Re2 Rad8 20. Rae1 e4  21. Nxe4 Rxd5 22. Nxc5 Rxc5 23. Qa3 Qd7 24. h3 Ra5 25. Qb3 Qd5 26. Qb4 Qc5 27.  Qxc5 Rxc5 28. f4 g6 29. Kf2 Kg7 30. Rd2 Rfc8 31. Re7 R8c7 32. Rxc7 Rxc7 33. Ke3  Kf6 34. g4 Ke6 35. Ke4 f5+ 36. Kf3 Rc4 37. Re2+ Kf6 38. Rd2 Ke6 39. Re2+ Kf6  40. Rd2 1/2-1/2

```
> 6 votes

# Answer
Simply stated, it's because of Black's backward d-pawn; see http://en.wikipedia.org/wiki/Backward\_pawn -- as opposed to other lines of this Gambit it gives White a definite weakness to focus on well through the opening and possibly the middle-game and beyond.
> 10 votes

# Answer
When I play the Smith-Morra gambit, I attempt to entice black into playing this move via `3. Nf3`:

```
[fen ""]
1.e4 c5 2.d4 cxd4 3.Nf3 e5 4.c3 (4. Nxe5? Qa5+) *

```

After `3. Nf3`, I haven't announced my intention to play the gambit since it could transpose into mainline Sicilian Defence (although, black's 4...Qa5+ might commit you to it; see my recent question here).

Black's move `3... e5` indeed protects black's `d4` pawn, since if `4. Nxe5? Qa5+`. However, white now plays the gambit move `4. c3`.

I think `...e5` gives white a better game than one of the usual variations. The usual themes with backwards pawns on a half-open file apply: ganging up on black's `d6` pawn and `d5` hole; if the `d6` pawn is pinned, the `e5` pawn is also weak. There's also opportunity to pile up black's `f7` pawn, which is typically awkward to defend using a minor piece. However, it's not really all that bad; it's somewhat similar to the Sveshnikov variation of the Sicilian defence.

Comments:

* I personally like swapping off white's dark squared bishop for black's `f6` knight, then placing one of white's knights at `d5`. Sooner of later, black will need to swap off his light squared bishop to dislodge the knight, thereby giving opposite-coloured bishops, a particularly important imbalance. If I can't find the right attack, I can still swap off into an opposite-coloured bishop endgame, which is likely an easy draw despite being a pawn down.
* **I find black's `...Bg4` to be a very annoying move**, since it pins the `f3` knight against the queen, and threatens `...Nd4`. This seems to be the main advantage of `...e5` over `...e6`. Keep an eye out for this move; in some cases, it can be a game-changer. Sometimes it's helpful to take time to play `h3` to prevent this move.
> 6 votes

# Answer
To summarize and without going into detailed variations, white has an easy game after e5 and all pieces can have perfect positions.

* Bc4 with pressure on f7, Nf3 attacking the e5 pawn, and if black is not careful Ng5.
* Bg5 and Nd5, pinning Nf6 in some variations.
* Qb3 adding more pressure on f7 and b7.
* After castling, doubling rooks on the d-file with pressure on the d-pawn or bringing the rooks to the c and d files with possible threats like Nb5.

Positionally and tactically white should be winning!
> 3 votes

# Answer
Better is 3...e5, on account of 1.e4 c5 2.d4 cxd4 3.c3 e5 4.Nf3 Nc6 5.Bc4 Nf6 6.Ng5 d5 7.exd5 Nxd5 and now

A: 8.O-O Be7 9.Nxf7 Kxf7 10.Qf3+ Ke6 11.a4 g5 (11...Rf8 12.Qe4 Kd6 13.Qxd5+ Kc7 14.Na3=) 12.Rd1 g4 13.Qxg4+ Kd6 14.Qf3=;

B: 8.Nxf7 Kxf7 9.Qf3+ Ke6 10.a4! (10.O-O Na5 11.Bg5!) 10...Be7 11.Qe4 (11.O-O {see variation A}) 11...Qd7 12.O-O Rd8 13.f4 Kf7 14.Qxh7 Bf6 = (14...e4 =);

C: 8.Qb3= Schroeder-Krzyzanowski, corr. ICCF 2015, https://www.iccf.com/game?id=812611
> 0 votes

# Answer
You create a hole on d5 for the White knight and the e pawn can no longer defend f7.
> 0 votes

# Answer
This kind of opening does not give advantage so it is not played often. The loss of a pawn does not give enough compensation. If there is any compensation, it will be if it can be realized fast, in the opening.
> -3 votes

---
Tags: opening, learning, sicilian-defense, smith-morra-gambit
---


# Question
Title: Which currently active chess player tends to play complicated positions?
In earlier years, Michail Tal would be a candidate for this topic.

Which player could be a candidate today for regularly playing complicated positions ?

# Answer
> 3 votes
Alexander Morozevich probably obtains the most consistently complicated positions of any \>2700 player, although he has fallen off some since the mid-2000s.

Baadur Jobava is probably his rightful successor, but a recent string of horrible tournaments pushed him under 2700 and he is now sitting at 2699.

# Answer
> 1 votes
Richard Rapport plays a lot of novelties in the opening. You can search for it. The positions are not necessarily tactically complicated, but the novelties are interesting.

# Answer
> 1 votes
Nakamura, Mamedyarov, Topalov, Svidler, Shirov, Jobava

---
Tags: famous-players
---


# Question
Title: To what move depth should you analyze a chess position
I'm trying to learn a chess opening and using a chess engine (stockfish8) to analyze the position but I'm wondering what move depth should I set it to (e.g., 25, 30 35 half moves).

# Answer
Generally, the only reason running a chess engine at less than maximum power are time constraints or if you want to give yourself a chance to win, though in the latter case I'd still prefer to play human players instead.

Regarding the use of a chess engine **to analyze the position** in an opening in order **to learn a chess opening** I am wondering how you are going to practically do this? I mean, the engine will give you only a certain sequence of moves which it considers best play for both sides. It will not teach you the ideas/plans behind an opening which is the most important part and something which you can rely on if your opponent for instance does not play the expected move. It will not teach you about subtleties, like move-order changes or any sidelines.

I am not saying a chess engine is completely useless for studying openings. You could use it for practice games in a specific opening or you could study a certain alternative move in an opening (but that would be at a stage where you already know the opening somewhat).

For studying a new opening I'd find much more useful than an engine:

* any explanation of plans/ideas (this can be books, videos, or a coach/friend)
* a database
* following games of a Grandmaster who is playing the opening regularly (let them do the difficult analyzing part...)
> 5 votes

# Answer
I don't torture engines much when preparing openings as it makes almost no sense. I grew up from this.

No human can get anywhere close to engines in **dynamic** positions. That means your moves will be quite random in sharp positions and your opponent's will be also quite random (or very unprecise if it sounds better to you). There is also quite a little point in analysing **static** position to extreme depths. What for, does it mean something to improve by 3 centipawns on depth 40?

The engine evaluation may be based on some alien variation club players will never make playing unprepared. Evaluation of main line isn't important at all if it is almost certain that it won't happen. And that is exactly what engines expect, 100% precision. Engine will go to a minefield for one centipawn, not caring any mistake means immediate loss.

I doubt it makes much sense for grandmasters and I'm pretty sure it makes no sense for hobby players to waste time and electricity for calculations they will never be able to replicate at the board. If the line is too messy, you will either not be able to find correct moves at the board (if engine didn't see it early enough) or you will simply forget it sooner than you will be able to catch there someone unprepared (if you try to remember it by heart). I think people heavily overestimate use of deep engine searches for practical games. They behave like if it was 30% of a success while it may very well be 0.2% of it.

And here is beautiful example from last round of republic championchip where I had to win with white to make silver and my opponent (very dangerous 2500 player with sharp PC preparation) caught me unprepared in dragon sicilian and from engine perspective he just murdered me with black right from the opening.

```
1rr3k1/4pp1p/3p2p1/q2P1b2/2BQ2PP/1P3P2/2P5/2KR3R b - - 0 24

1...Bxc2 2.Kxc2 Qa2+ 3.Kd3 Rxc4 4.bxc4 Rb3+ 5.Ke4

```

After the game he told me that he knew taking on c2 leads to very good endgame with queen and five pawns against two rooks and four pawns. I didn't know anything so I had to make my decision at the board. Do I want to give a queen and suffer in this type of endgame or do I like to go with my king to the center? I was thinking about half an hour and it looked to me that marching king to e4 could be very easily winning position (maybe I found the only forced draw, I don't remember that exactly, but for sure I saw no single worse position for me in this variation). I made my march to e4 instead of giving up a queen, my opponent spent remaining 40 minutes calculating. I spent another twenty minutes of his time too, then I went to look on cups and medals as I was almost certain I'm winning (or at least not losing). Neither me nor my opponent found the -10 winnig strike for black that Komodo found on depth 5 in a few miliseconds. In the game I easily converted my extra rook as my opponent missed also the only forced draw (not completely obvious too) and the rest of variations were just easy wins for me.

Even in a dream scenario things can go really wrong. It is horrible strategy to go into a minefield for a few centipawns which is exactly what engines do. They don't help you in recognising minefields, they don't care about them. There is some value in doing deep searches, one can hardly find reason why lower depths would produce better chess related results than higher depths, but that value is very close to zero. It is much easier to measure time related results and they are horrible on higher depths. Even if you are comfortable with wasting the electricity, don't waste your time.

The stronger player you are, the more precision you want, obviously. But with today strength of computers, even GMs should be comfortable on under 1sec for unprobable variations to forget soon and on a few seconds for highly probabe positions to happen. There is always something to do if you want to see depth 50 result, it makes no sense but you can feel pretty comfortable with it, if you can for example prepare a breakfast in a meantime :-)
> 4 votes

# Answer
The depth of a Chess Engine is the Level of Play when you analyse the game . If you are aware of the ELO System of rating I would like to describe below .

1. 100 - 1000 :--\> Beginner
2. 1001 - 1200 :--\> Casual
3. 1201 - 1400 :--\> Average
4. 1401 - 1600 :--\> Intermediate
5. 1601 - 1800 :--\> Experienced
6. 1801 - 2000 :--\> Tournament Player
7. 2001 - 2200 :--\> Expert
8. 2201 - 2300 :--\> National Master
9. 2301 - 2400 :--\> Fide Master
10. 2401 - 2500 :--\> International Master (IM)
11. 2501 + -2800 :--\> Grandmaster / World Champions (GM)

Now when you set the Chess Engine depth to a Highest Level they play with the Strength of an IM/GM . The Depth what you should set is always on the category that you are in this ELO level .

Let's assume that if you are a 1600 Approx Player you must try defeating the Players who are about 1700-2000 ELo level . As you know when you climb up a stair case you should take 1-2 steps at one time and you just cannot leap at one shot you must try crossing the next levels and check where your standard is and then prceed on to the next levels .
> 2 votes

# Answer
Sorry to disappoint you but from my Chess experience I can say that when you play real Chess Tournaments or even in the Internet you would find Players of the above category have different way to produce the Openings .

When you play with a Player of 2300 + you would see that his openings are more ultra sharp and much more precise compared to a Player of 1500 Elo level . The Player with a 2300 + would get an opening advantage very soon and the Score of the Game would be a plus to him . Infact they will even defeat his low rated opponent within 15-20 moves .

A player with 1500-1600 Elo would play average openings with not so great quality but still he can give good competition .

For a better reference please download Stockfish/SmallFish if you have an iPhone and then go to the Game Difficulty Section and choose any one . PLAY with the APP for sometime and then you would realize the difference .

One more thing : I have given you the answer from a Player's perspective . Please let me know what exactly you are trying to achieve so that I can frame my answer accordingly if the above is not satisfactory .
> 0 votes

---
Tags: opening, engines
---


title: Computers finding computer moves

text:
# Question
Title: Computers finding computer moves
There are positions in chess where the only good move (e.g. only move that preserves equality) is very unnatural for a human player. For instance if this move goes against common principles or if it opens the king to a potential attack, a human might be less likely to play this move.

Have there been attempts to find such positions with a computer?

I am not interested in using this to identify cheaters (=humans using illegally computer help in chess).

I am more interested in whether this could be used to win equal positions against humans. For example with such analysis, one could improve opening preparation, steering towards positions where the opponent has to find a "computer move". Also in endgame studies it could be used for the same reason.

# Answer
One of the most common "unnatural" moves for a human is an under-developing move. Computers find them easily, as it's just another move to check but human's have invested time and energy developing a piece - why then move it back again?

Computers just crunch and then evaluate. Humans are much more emotive and have certain biases for development so it's very easy as a human to overlook a move that a computer would find in a heartbeat.

(one example might be re-routing a queen from one side of the board to the other, via the home-square - e.g. Qa5-d8-h4)

I realise this is a general answer but might help :)
> 2 votes

# Answer
Have you seen the Computer Chess Rating Lists competitions? They pit chess engines against one another for the purpose of **assigning chess engines consistent ratings**, and for **determining which chess engines are the strongest** using fair methodologies (such as by using controlled conditions and hardware).

I ask because in the process of doing this you can find games of chess engines (*with ratings much higher than humans*) playing chess engines (*with ratings much higher than humans*). Some of these games are **very strange** to watch.

These chess engines can see so many moves beyond what a normal human can (even GMs), that the moves they make are **very nuanced** and strange to us (and GMs).

**ANSWER**:

> **Have there been attempts to find such positions with a computer?** Indirectly, yes but as a consequence of pitting chess engines against one another. These games, and their odd moves can be downloaded and witnessed.

For example:

```

[Event "CCRL 40/4"]
[Site "CCRL"]
[Date "2016.11.25"]
[Round "351.6.759"]
[White "Fire 5 64-bit 4CPU"]
[Black "Stockfish 8 64-bit 4CPU"]
[Result "0-1"]
[BlackElo "3481"]
[ECO "B06"]
[Opening "Modern"]
[Variation "1.e4 g6 2.d4 d6"]
[WhiteElo "3324"]
[Termination "normal"]
[PlyCount "119"]
[WhiteType "human"]
[BlackType "human"]
[FEN ""]

1. e4 g6 2. d4 d6 3. c3 Nf6 4. Bd3 Bg7 5. f4 O-O 6. Nf3 c5 7. dxc5 Nbd7 8.
cxd6 exd6 9. Be3 Nxe4 10. Bxe4 Re8 11. Qd3 Nf6 12. Bxg6 hxg6 13. O-O Bf5
14. Qd2 Qa5 15. Re1 Rac8 16. a4 a6 17. Bd4 Bg4 18. Rf1 Ne4 19. Qd1 Rc4 20.
Bxg7 Kxg7 21. Qd3 Qc5+ 22. Nd4 Be2 23. Qxe2 Rxd4 24. Qe3 Rxa4 25. Qxc5 Nxc5
26. Rxa4 Nxa4 27. b3 Nc5 28. Nd2 Re3 29. Rf3 Rxf3 30. gxf3 Kf6 31. Kf2 d5
32. Ke3 Ne6 33. c4 dxc4 34. Nxc4 b5 35. Nd6 Ke7 36. Ne4 f5 37. Nc3 Kd6 38.
b4 Nd8 39. Na2 Nc6 40. Ke2 Nd4+ 41. Ke3 Kd5 42. Kd3 Nxf3 43. h3 Ng1 44. h4
Nf3 45. Nc3+ Ke6 46. Ke3 Ne1 47. Kd2 Ng2 48. Ne2 Kd6 49. Kd3 Nxh4 50. Ng1
Ng2 51. Ne2 Kc6 52. Nd4+ Kc7 53. Ne2 Kb6 54. Kd4 a5 55. bxa5+ Kxa5 56. Kc3
Ka4 57. Kd2 Ka3 58. Kc2 b4 59. Kb1 Kb3 60. Nd4+ 0-1

```

And in this game (**NOTE**) Watch WHITE's Knight in this match between move 12-15. WHITE spends 3 moves to relocate his Knight to an adjacent square (because he can see far enough ahead to want it there, and can afford 3 moves to get him there):

```

[Event "CCRL 40/4"]
[Site "CCRL"]
[Date "2016.11.25"]
[Round "351.6.716"]
[White "Stockfish 8 64-bit 4CPU"]
[Black "Fire 5 64-bit 4CPU"]
[Result "1-0"]
[ECO "A00"]
[Opening "Benko's opening"]
[PlyCount "208"]
[WhiteElo "3481"]
[BlackElo "3324"]
[FEN ""]

1. g3 e5 2. c4 Nf6 3. Bg2 Nc6 4. Nc3 Bb4 5. Nd5 O-O 6. a3 Bc5 7. Nc3 Bd4 8. Nf3
Bxc3 9. bxc3 d6 10. O-O Bd7 11. d3 h6 12. e4 Re8 13. Ne1 Qc8 14. Nc2 Bh3 15.
Ne3 Ne7 16. f4 Bxg2 17. Kxg2 exf4 18. Rxf4 Nd7 19. Rf1 f6 20. a4 Ne5 21. a5 c5
22. Qe2 Qd7 23. Bd2 Kh8 24. Ra2 Rac8 25. h4 Qc7 26. g4 Rg8 27. Be1 Nf7 28. Bg3
Nc6 29. Rb1 Rcd8 30. Rb5 Qc8 31. Nf5 Rd7 32. Rb1 Re8 33. Rba1 Qd8 34. Qf3 Nfe5
35. Qd1 Nf7 36. Kg1 Kh7 37. Kh2 Kg8 38. Ne3 Nfe5 39. Qe2 Rc7 40. Bf2 Rc8 41.
Nf5 Qc7 42. Bg3 Nf7 43. Rf1 Rcd8 44. Qf3 Nfe5 45. Qd1 Ne7 46. Ne3 N7c6 47. Kg1
Rf8 48. a6 b6 49. Raf2 Qd7 50. d4 Nf7 51. Nd5 Qc8 52. Qd3 Rde8 53. Rxf6 Qxg4
54. R1f4 Qd7 55. Bf2 Ne7 56. Qg3 Nxd5 57. cxd5 cxd4 58. cxd4 Nh8 59. e5 Rxf6
60. exf6 h5 61. Kh2 Re2 62. Rf5 Re8 63. Qg5 Rf8 64. Bg3 Rf7 65. Rf4 Qc8 66.
Qxh5 Rxf6 67. Rxf6 gxf6 68. Bxd6 Qc2+ 69. Kg3 Nf7 70. Ba3 Qc7+ 71. d6 Qc2 72.
Qf3 Qa4 73. Qd3 Kg7 74. h5 Kh8 75. Kf4 Nh6 76. Kf3 Qd7 77. Ke2 Nf7 78. Qf3 Kg7
79. Qe4 Kh8 80. Qe7 Qb5+ 81. Ke3 Qg5+ 82. Kd3 Qf5+ 83. Kc3 Qa5+ 84. Bb4 Qa1+
85. Kb3 Qb1+ 86. Kc4 Qa2+ 87. Kd3 Qb1+ 88. Ke2 Qb2+ 89. Bd2 Qb5+ 90. Ke3 Qb3+
91. Ke4 Kg7 92. d7 Qb1+ 93. Ke3 Qg1+ 94. Kd3 Qf1+ 95. Kc2 Qc4+ 96. Kb2 Qd5 97.
h6+ Kg6 98. h7 Qb5+ 99. Bb4 Qh5 100. Qxf7+ Kxf7 101. d8=Q Qe2+ 102. Kc3 Qf3+
103. Kc2 Qe2+ 104. Bd2 Qc4+ 1-0

```
> 1 votes

# Answer
First off, this is a very valid question.

The short answer is that no - to my knowledge, there are no programs that can somehow "steer" the game into positions where "unnatural" moves are good. While it is certainly possible to create such an engine, remember that a natural move is subjective.

However, you don't need a computer program to do it for you! You can do it yourself. Select a complicated opening, especially something like the Najdorf or some other sharp line, and you'll notice that there will be many opportunities for you to lead your opponent into muddy water - complex positions where you know the theory sue to computer analysis, and your opponent might not.

Here's the thing though; to attempt such a thing, you'd need to be a VERY strong player already, at least FIDE master I would say. The reason is that while grandmasters play complicated positions on purpose all the time, they have to do it to beat equally strong players. But they don't need to if they're playing against even a 2000 rated player, as they can just gradually outplay them, without need for double edged positions.

For practical purposes, I will repeat that complicated openings, which you shouldn't be playing in the first place unless you're a master level player at least, will offer an incredible array of tough positions which are amazing fro computers, yet in which humans make plenty of mistakes.

Also, note that good players will play unnatural moves if they are good! That's part being a good player - considering all possible candidate moves.

To make myself even more explicit, Kasparov once said that even he can't calculate everything. In complex positions, there naturally tend to be no real natural moves. That's where computers dominate.

(I am an expert rated USCF player)
> -1 votes

# Answer
First of all I think that your question needs to center on how to discover unusual moves that hold or improve your position evaluation.

First of all, in equal positions sometimes any move is equally good. Therefore, is the frequency of moves what gives us an indication of the preferred variations that correspond aproximately to the same number of plans. In this circunstance an engine is almost uncapable to discover a move of value, due to the horizon effect. You should select by yourself a potential move.

This kind of position can be of advantage for your purpose. You can explore withing the several moves ordered by the engine the second or the third alternative and explore its continuation (different from chess database moves) and adjust the resulting line with your chess knowledge and your plan.

A different approach that sometimes I have experimented is to find positons in which there are only one best move according to an engine and the remaning moves have an inferior valuations of at least 1/4 of pawn. This is a kind of position that I consider risky for my oponent and if this variation is preceded by an unusual move as chosen with the method previously explained, you have build a potential surprise for your opponent that could be useful for your preparation.
> -1 votes

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Tags: opening, computer-chess, preparation
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# Question
Title: What exactly means centipawns field in stockfish/uci output?
According to this page:

```
cp
        the score from the engine's point of view in centipawns.

```

but is it a score for the current (start) position of the game that I feed to engine, or it is a difference between start and final(when coputations completed and best line found) scores?

And the range in which this value varies is unclear to - how could it be as big as 6000 that I sometimes get for my positions? That would be a ton of figures:)

# Answer
It's the score of the *current* position, but it is computed by static evaluation (i.e. counting pieces, pawns, pawn structure, king safety, mobility, etc.) of positions arising in the program's search tree, and applying the minimax algorithm and alpha-beta pruning.

A cp-score of 6000 does indeed mean the engine thinks it's 60 pawns (centi means 1/100) = between 6 and 7 queens ahead. Because it wasn't able to find a forced mate, it will just try to get the highest possible point advantage, knowing that this will bring the game closer to mate. In practice, a score of (+/-)150 is already decisive most of the times.
> 7 votes

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Tags: engines, stockfish, uci
---


title: Enter non-game moves in ChessBase

text:
# Question
Title: Enter non-game moves in ChessBase
One problem I have with ChessBase is that often I need to enter moves that are non sequential in a comment. For example, I might have a comment like "with the idea of g5 followed by Bb7". There is no way to enter these moves, I just have to type them in as text. As an extreme example of non-sequential moves, there is of course the chess game from "Through the Looking Glass" which features many out of order (illegal) moves.

The bizarre thing is that ChessBase has a "with the idea of" Informant symbol (the delta), but this annotation is useless, because you always use it with a non-sequential move, which you cannot enter.

Is there any way around this dilemma? Note that I am using ChessBase 9.0, so more recent versions may have additional capability.

UPDATE -------------------------------

I tried entering a null move according to an answer below, and this is the result:

So, this kind of works and allows use of the annotation symbol, but it does look a little kooky with the dashes.

# Answer
Enter a null move by ctrl+alt+0.
> 4 votes

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Tags: chessbase, annotation
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# Question
Title: What are the main differences between 2...d5 and 2...e5 in the anti-Caro-Kann?
In the anti-Caro-Kann (also known as the Pseudo Panov-Botvinnik or Panov's little Brother), reached by 1. e4 c6 2. c4, what are the main differences between **2...d5** and **2...e5**?

```
[FEN ""]
[StartPly "4"]

1. e4 c6 2. c4 d5 (2...e5)

```

The reason why I ask this question is because I play the Black side of this opening, using 2...d5, as suggested in *The Caro-Kann: Move-by-Move*. I also own *The Panov-Botvinnik: Move-by-Move*, which covers 2...e5 but from White's point of view, so Black ends up making a mistake, or the author annotates the White moves more heavily.

# Answer
> 1 votes
They are based on two different strategies - in the e5 line, black focuses on preventing (or making less favourable) the d4 central grab. Black may continue with Bc5, d6, Qc7 (defending laterally), Nf6, Nbd7, Be6. White has a small space advantage thanks to ownership of d5 but probably not a lot more. It's a slow but solid development plan.

In the d5 line, black seeks to clarify the centre straightaway. After 1. exd5 cxd5 2. cxd5 black has some open lines and leaves white with an isolated queen pawn, however, after 2...Qxd5 3. Nc3 and 4. d4 white has a small development advantage. The game becomes about whether white's development advantage outweighs the potential weakness on d4.

# Answer
> 2 votes
I don't play this from either side, but apparently **2... d5** leads to positions known as **isolated queen pawn** (isolani) which can also result from many other openings. Look it up, there is lots of information out there about this. There is a fairly standard plan in these positions. White wants to avoid getting into an endgame where the pawn would be a weakness. Typically black would try to control the square in front of the isolani (i.e. d5 in this case) preventing white from exchanging the pawn playing d5 himself. White usually has a bit more active play in the middle-game.

I don't like **2...e5**. If white attacks the e5 pawn, e.g. with 3. Nf3, black is almost forced to play 3...d6 and the set-up with pawns on e5,d6 and c6 is gernerally not good. White can later play d4 and open the d-file after which the pawn on d6 might get weak.

# Answer
> 1 votes
There is nothing similar with these two variations. Panov is unbalanced open game, both sides have some pros and cons.

The e5 is weak move, it leads to something that I think is called old indian defence, KID with bishop on e7, which makes black setup way too passive. No pressure on h8-a1 diagonal, no pressure on the e-file, no kingside attack.

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Tags: opening, caro-kann
---


# Question
Title: Is it disrespectful to pay attention to other things while playing?
Sometimes when I'm playing a variation that I'm comfortable with I get bored while waiting for my opponent to move, so I get distracted and start to pay attention to other things around me.

I know that focus is important, and being distracted can put me on short pants when playing, but lets, for the purpose of this question, ignore that.

As an example, yesterday I was playing with my uncle with no time limit, and the Real Madrid game was on. While waiting his moves I took a (sometimes not so) quick look at the TV.

Obviously, my uncle is someone I respect. When doing this I had (and always have) no intention of looking presumptuous or insinuate the game is easy (and I don't think my uncle got me wrong).

But not everyone I play against knows me as well as my uncle. Does this look bad when playing? Can my opponent be offended?

# Answer
> 3 votes
I don't think this question is really chess related. For an informal (no tournament) situation like you describe I don't see much difference in whether you play a game of chess or do some other activity together with somebody.

Whether it is disrespectful depends on your cultural background and also on how well you know each other. For instance some people like (trash-) talking during informal games.

Regarding tournament games you can read about the FIDE rules of conduct in article 11 here, particularly article 11.5 which states:

> It is forbidden to distract or annoy the opponent in any manner whatsoever. This includes unreasonable claims, unreasonable offers of a draw or the introduction of a source of noise into the playing area.

In practice you can do almost anything which does not affect your opponent directly. For instance it is very common that players get up and walk around, as is eating/drinking at the board.

# Answer
> 4 votes
Whether or not your opponent is offended may depend on your local culture outside of chess, and might also depend on the situation in which you're playing the game. In a tournament with slower time controls, it's not uncommon to even see players get up and walk over to watch other games in progress. On the other hand, if you're just playing a casual game with someone then it's probably polite to pretend you're interested in the current position because otherwise your opponent may think that you don't actually want to be playing with them.

# Answer
> 2 votes
In a tournament game, as long as you do not distract the other player and are not consulting help with your game, you may do as you please. The other player will not be able to persuade a tournament director that you are distracting him if you are just looking (or walking) around.

I think the more important question is how well you maintain your train of thought through the game. While you are playing purely on technique, such as in an opening variation, you may be tempted to spend time on something else while waiting for your opponent's move. However, even Grandmasters have misplayed openings because they left the board, and when they returned expecting the "only move" to have been played by their opponent, responded to that move, only to realize that their opponent had played something else.

If you do lose focus on the game while playing a known variation, make sure you double-check your opponent's move when you return to avoid that mistake.

# Answer
> 1 votes
The main etiquette rule to follow when playing a game of chess with someone is to not do anything to distract your opponent while he's thinking about his move. I think it's OK to watch soccer on TV when it's your uncle's turn, but I wouldn't do it on your own move.

# Answer
> 1 votes
I would say no. There was some training school in the 80s where you were not supposed to look at the board much but try to look anywhere else. The idea was to only see the board in your mind. Some famous players (e.g, Shirov I believe) adopt this method.

# Answer
> 1 votes
Definitely be in any profession it is not advisable to pay attention to other details, but sometimes in chess it is important that you look here and there and take your eyes from the board during a tournament play.

When two people play the game of chess sometimes they lose the presence and they enter into a world of illusion. This happens majorly when the game extends for 3-4 hours. During the openings phase it is not advisable but in middle and endgames when you require a definite plan sometimes a few secs of break from the game can re-energize you and can make you think better. Your brain even gets stuck when you are playing a hard game for a long time. Top players do this at their levels in classical chess not in blitz.

Now a concrete rule: Blumenfeld's rule: Here the rule says that "after a prolong deep calculation it is important that you look away from the board for sometime which helps you to skip blunders".

So sum it up, look here and there sometimes during a game but do not make someone else's business yours, and take few breaks during long calculations.

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Tags: etiquette
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