Here are my observations:

Both games are long. The average game lasts about 40 moves. No wonder you ran out of time!
I can see you know the principle that when you are ahead in material, trade down. However, both games involved your king being chased around by the queen. You are not trading the right pieces
You don't need to be up that much material to win a technical game

Advice:

Learn to play more efficient chess. I'm guessing it took you some time to figure out all the branches in the tactical analysis

I feel that you are trying to find the best move by calculation. I.e. that you are trying to see 5 moves ahead to see if you can win more material. What I believe you should do is aim to look 2 and a half moves ahead and base those moves on your evaluation. This is particularly useful in non-tactical situations.

For example, in your first game you win material and have to solidify. At move 31, you make life more complicated for yourself with 31...b5. Why not offer to trade queens with 31...Qe4, which needs almost no calculation? That move follows the principles and is in line with your evaluation of having to solidify and trade down.

When ahead in material, your first priority should be to trade queens. This is a big reduction in material and reduces the opponents counter attacking chances a great deal
Don't spend so much time gaining more material. Spend time either solidifying your position or reducing the opponent's counter chances


Minimal number of moves before castling in Chess960

The three first steps:
There are 90 positions where n(P)=1
For White to be able to castle short at once, he needs to have Kf1, Rg1 in the initial position. Then there are 5 possible spots from the second rook, 3 for one bishop and 2 for the other one, and finally 3 remaining spots for the queen. The knights go to the last two spots.
There are 64 positions where n(P)=2
36 of them with Kf1, Ng1, Rh1: White can play 1.Nf3 or 1.Nh3 and 2.0-0
28 of them with Rg1, Nf1, Ke1: White can play 1.Ng3 or 1.Ne3 and 2.0-0
There are 242 positions where n(P)=3
please double-check this part
Here are the different configurations and the number of relevant positions:
xxxxxQKR 18
xxxxxBKR 36
xxxxxRKR 18
xxxxxKQR 18
xxxxxKBR 24
xxxxKNNR 8
xxxKNNRx 6
xxxKNRNx 6
xxxKRNNx 6
xxKRxNNx 4
RKRxBNNx 2
EDIT: Now I have a doubt for these two cases. Is castling allowed in Chess960 in spite of a piece being "on the way" on e1 ?
xxxxKBRx 24
xxxxKQRx 18
xxxxKRBx 36
xxxxKRQx 18
Total:242
Once we reach n(P)=4, we cannot ignore Black's play anymore: for instance, QNRNKBBR looks like it should have n=5, but actually it has n=4 because of the sequence 1.f4 b5 2.Bxa7 Qxg2 3.Bxg2 Nc6 4.0-0. Counting by hand becomes too fastidious and hazardous: a software program is needed.

On the other hand, after clarification by the OP, I believe 7 to be the maximum value of the function P->n(P).
If Black wasn't allowed to "help" we could build only 2 positions with n(P)=9; Here is one, the other is similar with RKBBNNQR on the first rank.
[FEN "rkqnnbbr/pppppppp/8/8/8/8/PPPPPPPP/RKQNNBBR w - - 0 1"]

In a series problem where White plays alone he would need 9 moves in order to castle. But since Black moves are taken into account, White actually can castle on move 7 from that diagram if the game goes something like 1.b3 d5 2.Qa3 Qe6 3.Nb2 Qxe2 4.Nd3 Qxf2 5.Bxf2 Nc6 6.Be2 0-0-0 7.0-0.


There's a variety of reasons why openings are commonly named after nations (but most commonly would surprise me), maybe due to an individual player of the nation, e.g. Spanish (Ruy Lopez), English (Staunton), maybe due to a group of players in one nation e.g. Italian, maybe due to an event involving the nation e.g. Scotch (named for a correspondence match between Edinburgh and London in the 1800s), and I suspect a number of other reasons, including "we don't really know"

Wikipedia list of chess openings named after places might be a good place to start researching this


Do some chess players actively train moving the pieces on the board quickly?

I'm a FIDE master and in my experience I've never come across any material on how to physically move pieces faster. There's not a lot you have to do: pick up the piece, move your arm to where you want to move the piece, and let go. As you play more this becomes second nature, to the point where training wouldn't make much sense.

As for short moves costing less time, this usually isn't a factor in blitz/bullet games; the exception is when you're about to flag and just need to make moves quickly. Then moving a piece 1-2 squares can be better than moving it across the board. Also, if you move pieces that are physically closer to the clock, you can save very small (but possibly precious) amounts of time. So for Black it would be moving pieces on the right side of the board, and for White the left side. Again, such strategies would only be implemented when you're down to literally a few seconds.


Generally white tries to develop a kingside attack by pushing the kingside pawns. Blacks strategy is less fixed. I always try to get counterplay on the queenside and I usually do get some play, but the white attack always stays dangerous.

In this game by Magnus Carlsen you can see some typical ideas:

The Qd2-Be3 setup.
Bg2 and going for f4.
0-0! Contrary to the open sicilian, castling long would be suicide here.
Bringing the Nc3 to the kingside and kicking out the d4 knight with c3.
Nh3 is a bit unusual, but it speeds up f4. Completely normal would be Nf3-h4.

Carlsen-Wojtaczek:

rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1
1. e4 c5 2. Nc3 d6 3. g3 Nc6 4. Bg2 g6 5. d3 Bg7 6. Be3 e5
7. Nh3 Nge7 8. f4 Nd4 9. O-O O-O 10. Qd2 Bd7 11. Nd1 Qc8
12. Ndf2 Ndc6 13. c3 b5 14. fxe5 Nxe5 15. Bh6 N7c6 16. Bxg7
Kxg7 17. Nf4 Qd8 18. Rad1 Rc8 19. Qe2 h5 20. d4 cxd4 21. cxd4
Ng4 22. h3 Nxf2 23. Qxf2 Ne7 24. Rd3 b4 25. Rf3 Qe8 26. g4
hxg4 27. hxg4 Bb5 28. Re1 Qd8 29. g5 Qb6 30. Bh3 Rcd8 31. Be6
Be8 32. Nd5 Nxd5 33. Bxd5 1-0


No, you cannot force white to play c4 and end up in a KID.

However, if you want to avoid the Pirc, you have several options after 1. d4 Nf6 2. Nc3.

... d5 is the most popular and you usually end up in easy to play positions. E.g. you can fianchetto your bishop to g7, attack the center with c5, etc.. You need to be prepared for the Hübsch/Blackmar-Diemer Gambit after 3. e4, but that is nothing to be afraid of.

... c5 to attack the center immediately

... e6 which can transpose into the French defense


You may have been in a fight or not.  Top players do not fight that way they make the moves best for their position.  Sometimes they delay castling but not to fight the opponent.

This seems to be a tactic used by weaker players who might want to mount an attack on the other king.  The position should decide whether that is the best strategy or not.

Not sure why you two  did it that way as there had to be better moves available.  it looks more like you all were struggling to just make moves so did what you did. So  being a bullet game might explain some of the moves that I would not have considered.

That said I would have just moved the white king up earlier and not castled at all as there is no danger of an attack and it would ensure that my king has an endgame advantage should black castle.   I note that is what black did to white later.

But then I would have made a number of different moves earlier on that would have changed the entire game making the question moot:)


How do I get to the next level of chess skill?

When I was in the same situation, Jeremy Silman's How to reassess your chess helped me a lot. It made me reconsider the basics of the game. I now have a much better undertanding of what goes on during a game, and I got from 1700 to 2000 Elo in the process. Just don't take his method too literally (he recommends making up "dream positions", which is just not my thing).


Should one actively search for a checkmate ('hunt the King') in the middlegame?

There is no overarching middlegame strategy that trumps all other strategies.

Both middlegame strategies listed are viable general strategies to play for, if the position allows it. What makes a difference are your own preferences; if you love tactics and mating attacks then you should probably go for middlegame positions that allow you to play in that manner, and similarly if you like calmer positions you should probably go for positions that aren't as sharp. Objectively speaking there isn't really much saying that one playing style is better than the other.


What is the lowest chess title you can get?

According to this Wikipedia entry, the lowest FIDE title is Candidate Master (CM), which requires an ELO rating of at least 2200. Obviously national chess federations offer their own titles, often with lower requirements.


Are banter blitz players who draw arrows on the board during the game breaking the FIDE Laws of Chess?

I agree that it would break the FIDE rules against note taking, but this is not a FIDE tournament; it is online blitz on Lichess, so FIDE rules need not apply. You'd have to look at the Lichess terms of service instead. They say

  Cheating. We define this as using any external assistance to strengthen your knowledge and, or, calculation ability to gain an unfair advantage over your opponent. Some examples would include computer engine assistance, opening books (except for correspondence games), endgame tablebases, and asking another player for help, although these aren’t the only things we would consider cheating.

The definition is open-ended so it's really up to the Lichess administrators to interpret. Does drawing an arrow on the board during a blitz game "strengthen your calculation ability?". Perhaps, but one could also argue that it makes you waste precious time, so it is probably more of a handicap than anything else. More importantly, just the fact that the Lichess user interface supports drawing arrows during a game (something which I had never noticed, despite being a frequent user!) may reasonably be interpreted as implying that the administrators approve of that use.

I don't think the "banterers" who stream their games draw arrows as a calculation aid, but rather to communicate their ideas to their audience. I'd love to hear from anyone who uses this feature and finds it helpful while playing blitz for non-streaming purposes. (Arrows might be more useful for correspondence chess, but there you are definitely allowed to use analysis boards, opening books, notes, etc., so arrows shouldn't be a problem.)


Now that FIDE has just announced BIDDING winners to be the official FIDE clock does that mean we have to buy those to play in their tournaments?

Now they they have selected them do we need to buy those to play in
  FIDE tournaments?

Certainly not! FIDE has never required players to buy any equipment to play in FIDE tournaments. We players have never been required to buy any clocks, sets, pieces, memorabilia, etc. The only two things we have to pay for are the appropriate level of membership of our national federations or associations and the entry fees charged by the organisers.

  I would feel better if they had tested the clocks to ensure they were
  good quality and worth the money we pay for them instead of awarding
  the seal of approval to the high bidders.

You appear to be ignorant of the FIDE Chess Clock Bidding Procedure. Not surprising given the lack of clarity of much of the FIDE site particularly after the latest munged redesign.

Here are some relevant sections of the bid document:

  11. Evaluation Methodology

  11.1 The evaluation methodology used by FIDE for this ITB is based on “the lowest-cost / highest-reward, substantially compliant offer”
  approach.

  11.2 FIDE will determine which offers are substantially compliant, and will reject noncompliant offers. Compliance refers to whether or not
  the offer substantially meets the quantitatively and qualitatively
  defined criteria as per the requirements and other qualification
  criteria as stated in the ITB documents.

  11.3 FIDE will choose the lowest-cost / highest-reward offer among the substantially compliant offers. Various factors such as the price of
  the goods, the full life-cycle costs and service costs will be taken
  into account.

  11.4 All evaluation criteria use by FIDE are non-discriminatory.

  11.5 FIDE will use three main categories of evaluation criteria: (1) formal, (2) technical and qualification, (3) financial.

  11.6 Formal criteria allow checking for compliance with specific mandatory requirements in the present ITB. Offers that do not meet the
  formal criteria will be rejected.

  11.7 Technical and qualification criteria are derived from the requirements as well as from qualification conditions. FIDE has
  developed technical and qualification criteria for evaluation
  according to a weighted scoring.

  11.8 Financial criteria include payments to FIDE, royalties to FIDE, and guaranteed prices for FIDE purchases.

Note that what is being bid for is primarily marketing rights:

  2. General Provisions    ...
  2.3 FIDE shall grant the winner(s) a non-exclusive right to use the FIDE logo in conjunction with the words “FIDE Championship Clock”,
  “Official FIDE Chess Clock” and/or “Chess Clock Recommended by FIDE
  for National Federations” for one or more models included in the bid.

  2.4 This right shall be granted for three (3) years starting October 01, 2019, and ending September 30, 2022.

  2.5 The rights to use the FIDE logo and the clock designations as per Clause 2.3 above shall be provided to the winner(s) in consideration
  for:
  a) lump-sum payments to be made to FIDE for each model of the chess clocks that
  are included in the bid;
  b) royalties to be paid to FIDE for each wholesale or retail sale of chess clocks that
  are included in the bid for the whole duration of the contract;
  c) an obligation to supply chess clocks to FIDE and/or national chess federations at
  a fixed price or/and with discount from the standard market price (royalties as per
  subcl (b) hereof do not apply for such supplies).
  ...
  2.7 FIDE retains the right to freely certify other chess clocks for competition use after testing. However, no other chess clocks could be
  designated as the “FIDE Championship Clock” or the “Official FIDE
  Chess Clock” prior to the expiry of the three-year period, i.e.,
  September 30, 2022.

  2.8 FIDE shall use the model(s) designated as the “FIDE Championship Clock” in its top-level competitions (Chess Olympiad, World
  Championship Match, Candidates Tournament, World Cup, Grand Prix)
  during this three-year period. No more than one bidder shall be
  declared a winner for this designation.  Bidding Procedure – August
  05, 2019.

  2.9 FIDE shall use the model(s) designated as the “Official FIDE Chess Clock” in its other official competitions included in the FIDE
  Calendar (e.g., World Seniors Ch., World Team Ch., World Youth Ch.)
  during this three-year period.

  2.10 FIDE will make available its development fund, subject to certain criteria established solely by FIDE, to subsidize, in whole or
  in part, the purchases by its member federations of the clock models
  designated as the “Chess Clock Recommended by FIDE for National
  Federations”.

In other words, clocks which win the bid must be available to member federations at subsidized prices. Other clocks which meet FIDE's technical specifications and which are consequently approved separately by FIDE may be used in ordinary level FIDE competitions.


Moving a pawn to attack a piece on the 5th or 4th rank

In the second example, after a2-a3, black does not have to retreat his dark squared bishop but can instead play ...Qxd4 when after axb4 Black can follow up with Qxd3.


What are some of the most unsportsmanlike conducts witnessed in over-the-board play?

Here are some examples of unsporting behaviour I have heard of before:

Kicking opponent under the table (from Josh Waitzkin in the Chessmaster tutorials)
(Added for interest) Running down the clock in correspondence chess with the aim of waiting for an opponent to die of old age (this shouldn't be a major issue under the ICCF, as games with deceased players are now cancelled or substitutes are called, but they could be misrecorded as a loss on time)
Using an iPhone for analysis (hat tip to @SmallChess)


How many games can be stored in Chess.com with a free account?

I believe the answer is as @double-beep said it. You cannot permanently delete a game from chess.com's archive, and I do not believe there is a way to make it so that you cannot see it. There are, however, a few limited filtering options so you can filter your games, but other than that you cannot delete a game. Also, there are an unlimited amount of games stored on chess, com's database. Anyone can see your games (not the ones played against the computer however), and you can see anyone else's.


Why is Ne4 considered as an inaccuracy whereas it is one of very few moves which saves d3 pawn?

Calling it an "inaccuracy" is nothing more than the engine saying that it evaluates the position after one move to be a certain amount better than after another move. It doesn't necessarily mean a move is "bad".
Both d-pawns cannot be kept no matter what Black does. After 1...Ne4, if White plays Nxe4, the recapture will leave the c4 knight without a defender, and it doesn't have a lot of places to go. White can win the pawn on e4 and attack that knight. And the dark squares around the Black king are just a bit weak. Black is still winning though.
If instead Black plays ...d4, this forces some trades. Simplifying the position seems like a good idea for Black, since they are winning. Overall Stockfish likes this option better.
Here's a comparison showing what the next few moves might look like for each option:
[FEN "r2q1rk1/1p3ppp/p4n2/2Pp4/1Pn5/P1Bp3P/3N2P1/R2QN2K b - - 4 21"]

1...Ne4 (1...d4 2.Nxc4 dxc3 3.Qxd3 Qxd3 4.Nxd3 ) 2.Nxe4 dxe4 3.Qg4 g6 4.Qxe4 *


Are Elo ratings adjusted after each match, or after each tournament?

Short answer: Neither

Elo-ratings are not ajusted for calculation after each game, they are not adjusted after each tournament either.

For all games played during one month, each player is supposed to have his last published elo-rating. If I am 2300 on the 1st of November and we play together November the 29th, your rating will be calculated by considering that you have faced a 2300-player. Whether I have gained 50 points in a previous tournament from 5 to 12 of november, or lost 100 points from novermber 16 to 23, will only be relevant for my rating on December 1st, and for my opponents in December and thereafter.

In your example, the second method applies. But there won't be any ajustment after the tournament if one of your three players plays another tournament within the same month.


Can you compile Stockfish on Windows without Unix/GNU?

The stockfish source code can be easily compiled with gcc, Visual Studio, XCode etc. In Visual Studio, create an empty project, use the mouse to drag all files in Stockfish into the project then press the compile button. Very simple.

The only reason that Visual Studio is not listed in the documentation is that the website maintainer (Daylen Yang) is a Mac and Linux user. He doesn't have Windows installed so he didn't care about it.


In Chess, are there simple "mechanics" that amateurs can learn to improve their game?

Good question, and I think that there are a lot of different common patterns/tactics that improving players would do well to learn:

(very roughly ordered from simplest to most difficult)

"Simple" tactics and endgames

knight forks and bishop forks - get in the habit of just seeing the squares that would be forked instead of needing to spend time looking
rook and queen forks - very similar to the above, but sometimes these are more difficult to see for some reason (i.e. white king on g1, knight on g3, Rg2+ would fork the two if the rook is defended)
king and pawn endgames - as mentioned in your question, the rule of square is crucial.  At the end of a long variation leading into a king and pawn endgame, just knowing whether or not the pawn will queen is often the difference between a win and a loss, and this trick will save a lot of time, often during time pressure.
drawn bishop and rook pawn endgames - again, if you know that a rook pawn and the wrong colored bishop will only draw, this will enable you to save time and half points.
drawn knight vs pawn endgames - sometimes a lone knight can fight successfully against the enemy king and pawn, sometimes not.  At a certain level (1900+?) it's important to know when the king and pawn win and when they only draw.  That's probably a separate question on its own...

Rook endgames

Lucena position - the Lucena position is the most common method of winning with a rook and extra pawn vs rook.  It's not terribly difficult to commit to memory either - spend 5-10 minutes and learn how to win when you get your king in front of your pawn!
Philidor position - the Philidor position is the most common drawing method if you are down a pawn.  Again, doesn't take much time to learn the basic position, and a good investment if you want to save a few draws in your games.
cut off king - if the enemy king can be cut off along a file or a rank, usually the stronger side will win.  However, learning the exceptions to this rule is important as well.  This is far less common than other winning rook endgames though, so less important if you just want practical knowledge.

Piece relationships and domination

bishop dominates knight - a picture is worth 1000 words...

king dominates knight - similar to king and pawn vs lone knight...

More complicated endgames

queen endgames - learning how to win with an extra pawn in a queen endgame can be valuable, as can learning how to defend.  There are few very common tricks (walking your king close to the enemy king to allow for cross-checks, deciding which corner to run to when you are on the weaker side, etc.) that are useful.  Again, this might be worth its own question.
bishops of opposite color - many times bishops of opposite color are a quick draw.  Not always though!  Learning some of the patterns used to get a win with an extra pawn or two in this endgame will allow you to win as the stronger side, and avoid losing as the weaker side.  Common patterns/tricks include two pawns vs no pawns separated by a single file (many times a draw), learning how to win with two pawns separated by 3+ files (hint: king helps the pawn barricaded by the enemy bishop), and learning how to draw these positions.

Tactics and mating patterns

Learning some basic mating patterns or typical tricks can be useful as well:

Greek gift Bxh7+ sacrifice - if black doesn't have a knight on f6 and white has a knight on f3, queen on d1, and a bishop that is attacking h7, it's imperative to at least check this sacrifice.  The Art of the Attack has a whole chapter dedicated to this common theme.
Checkmate patterns - spend an hour learning patterns - the wikipedia article is a great start, but Art of the Checkmate is the authoritative book and it is available fairly cheap on Amazon...

Well, that was a lot, please feel free to add or embellish this answer if you think of more patterns and tricks!


How do they determine the starting position for Fisher Random / Chess 960?

8.4.3. Drawing of positions

● Set up of the pieces will be decided by a drawing made by Fischer Random Generator
software with all players present 15 minutes before the start of the first game of
each time control. This setup then will be used for both games. The players will
attend this drawing, and will then be given time before the start of play to confer
with a second.

Found in the download here: https://www.frchess.com/regulations

Interestingly, if the classical position is picked then they pick again.


Yes, you're right that this is a draw because of stalemate. There is no better solution; White is two pawns behind, his king is exposed, he can't profit from the pin on the bishop and he can't safely win the a7 pawn. Without this tactic, black could just push his f-pawn towards victory.


Inconsistent timings of world championships

Due to funding and other problems with FIDE, the world championship schedule has been changed many times during past few years. TLDR: After the title reunification match in 2006, there was a tournament in 2007, followed by matches in every two years, starting from 2008. The 2013 match was an exception.

The match in 2006 was the reunification match between the FIDE world champion (decided in knockout tournaments by FIDE) Topalov and the classical world champion (decided by matches against the current classical world champion) Kramnik. Before the match, FIDE had announced that there is a world championship tournament in 2007. Kramnik and Topalov agreed to that. Before the 2007 tournament, there was also an agreement that if Kramnik (2006 winner) does not win, the winner of 2007 tournament needs to play against him in a match in 2008.

After that match, FIDE had decided to have a 2-year world championship cycle. However, there were some problems with some players withdrawing from the qualification tournaments because rule changes by FIDE, see e.g. the list in Wikipedia's page on the 2012 match or Carlsen's interview. FIDE apparently reacted to that and shortened the world championship cycle: the qualification cycle for the 2012 match started in 2008, and the qualification cycle for the 2013 match started in 2011.

As to when it was decided that there are matches in both 2013 and 2014, my memory fails me. The lists in Chessbase and FIDE web site, both dated on March 28th 2012, are different. The FIDE contract with Agon in early 2012 might also have something to do with it.


Why does Fishtesting test Stockfish against itself, not other engines?

The point of fishtesting is to test if a newer version of Stockfish has become stronger. The definition of stronger is it beating its previous version.

I'm not sure how testing each new version against an engine like Leela would help. Your idea might be only accepting a new version of Stockfish if it performs better against Leela than the previous version of Stockfish did. So now each version of Stockfish is guaranteed to play better against Leela, but not guaranteed to be a better chess player overall. The reason is that Stockfish could rely on certain characteristics in Leela's play to win more games.

EDIT - I thought of an example that might help here. Suppose you were rated 1500 a few years ago, and now you're 1800. If you played your past self in a match it's clear you would win. But for the sake of argument it's possible your 1500-self would perform better against Kasparov than your current 1800 self. Maybe the 1500-self was less conservative and took way more risks. This manages to beat Kasparov in a rare game, while your current 1800 self would lose every time (yet the games would be slightly closer on average).


How many steps to mate the only king with all pieces?

Your first question: It takes 6 moves to mate the black king.
The only move is 1.e2-e4. All other white moves would take more than 6 moves... Also after 1.e2-e4 there are a lot of variations to long to post it right here.

The simplest way is to get the details and answer the second question yourself is using the program popeye, see http://sourceforge.net/projects/popeye-chess/

Final remark: There is a well known chess problem with white initial position and black king on h4. How to mate in 3 (white to move...)


Can tactics be reduced to a finite number of simple patterns that can be learned?

I would say that, indeed, the vast majority of tactics falls into some kind of pattern and there are a number of them but not too many.

In my opinion there are two issues that you need to improve in order to improve tactics in your games.  First, you need to know the basic patterns, that is you have to know how they look like and what is the main idea in exploiting them.  Often the basic ideas of the pattern cannot be applied out of the box and you will need to find the right moves to actually implement the combination.  The second issue is that, of course, you have to spot these patterns on the board and exploit them.

For picking up the patterns a tactics book that presents problems grouped by patterns, together with some explanations how to exploit them, is very useful.  E.g. "Tune Your Chess Tactics Antenna".  To facilitate the second step, such books often have mixed exercises at the end, where you are not told what the pattern is you should find, but then almost any tactics book with mixed problems will be okay.


How are chess variations meant to be read

Visualization usually improves as you get stronger, and there are exercises that can be done to improve it.

When following lines in a book, most players use a board,  and sometimes two. The second one is used to explore those side variations,  without having to constantly reset the board and play from the first move. This can be done with either physical boards, or software, which makes it easier to follow a variation,  then go back to then main line with just a mouse click.


Can White win the endgame from game Kramnik-Carlsen, London 2010?

According to the analysis of GM Mueller, white is winning.

The game went: 65.Kf2 Kd4 66.Kf3 Kd3 67.g4 Kd2 68.Be6 Kd3.
And now 69.g5! wins in all the lines, while Kramnik played 69.Kg3?, after which the ending is drawn.

The entire game, with the analysis of GM Mueller:

[FEN ""]
[Event "2nd London Chess Classic"]
[Site "London ENG"]
[Date "2010.12.14"]
[Round "6"]
[White "Kramnik, Vladimir"]
[Black "Carlsen, Magnus"]
[Result "1/2-1/2"]
[ECO "D07"]
[WhiteElo "2791"]
[BlackElo "2802"]
[Annotator "Müller,Karsten"]
[PlyCount "171"]
[EventDate "2010.12.06"]
[EventType "tourn"]
[EventRounds "7"]
[EventCountry "ENG"]
[EventCategory "19"]
[StartPly "128"]

1. d4 d5 2. c4 Nc6 3. Nf3 Bg4 4. Nc3 e6 5. Bf4 Bd6 6. Bg3 Nf6 7. e3 O-O 8. a3
Ne7 9. Qb3 b6 10. Ne5 c5 11. Nxg4 Nxg4 12. Rd1 Bxg3 13. hxg3 Nf6 14. cxd5 exd5
15. Be2 Qd6 16. Qc2 h6 17. O-O c4 18. b3 Qxa3 19. bxc4 dxc4 20. Bf3 Rab8 21.
Ra1 Qd6 22. Nb5 Qd7 23. Qxc4 a5 24. e4 Rfc8 25. Qe2 Rc6 26. Rab1 Rd8 27. Rfd1
Rdc8 28. d5 Rc2 29. Qe3 R2c5 30. Nd4 Re8 31. Qd3 Qd6 32. Qa6 Rb8 33. Nb3 Rc2
34. Nd4 Rc5 35. Nb3 Rc2 36. Qd3 Rcc8 37. Nd2 Ng6 38. Be2 Qc5 39. Rb5 Qc3 40. f4
a4 41. e5 Nd7 42. Qxc3 Rxc3 43. Ne4 Rc7 44. Ra1 Ra7 45. d6 Ngf8 46. Nc3 Nc5 47.
Nd5 Ra5 48. Rxb6 Rxb6 49. Nxb6 Nfe6 50. Bc4 Kf8 51. f5 Nd8 52. Rf1 Ncb7 53. Re1
a3 54. e6 fxe6 55. fxe6 Nxd6 56. e7+ Ke8 57. exd8=R+ Kxd8 58. Rd1 Kc7 59. Ba2
Rg5 60. Nd5+ Kc6 61. Nc3 {#} Rc5 62. Rxd6+ Kxd6 63. Ne4+ Kc6 64. Nxc5 Kxc5 {#}
65. Kf2 Kd4 66. Kf3 Kd3 67. g4 Kd2 68. Be6 Kd3 {#} {A miraculous escape. It is
hard to believe that Magnus Carlsen got away with a draw despite being down a
piece.} 69. Kg3 $2 {Kramnik allows the king to penetrate too deeply.} (69. g5 $1 {Hiarcs 13, running on a 12-core machine and providing added information to the live commentary, calmly spat out a mate score with an irreductible winning line.
Here it is with some added analysis to clarify.} hxg5 (69... h5 70.
Kf4 Kd4 71. g3 Kc5 72. Kf5 Kd6 73. Ba2 Ke7 74. Kg6 Kf8 75. Kh7 $18) 70. g3 {
opening the gates to the deadly endgame weapon: the Zugzwang, which takes the
day once more.} Kd4 71. Kg4 Ke3 72. Kxg5 {#and here all attempts to defeat the
triangulation with the bishop will fail.} Kf3 (72... Kf2 73. Kf4 Kg2 74. g4 Kh3
75. g5+ Kh4 76. Kf5 Kh3 (76... Kh5 77. Bf7+ Kh4 78. Ba2 Kh5 79. Be6 Kh4 80. Kg6
) 77. Bb3 Kh4 78. Ba2 Kh5 79. Be6 Kh4 80. Kg6) 73. Kh4 g6 74. Bf7 g5+ 75. Kh3
Kf2 76. Kg4 Kg2 {and now a triangulation with the bishop wins it.} 77. Ba2 Kf2
78. Bd5 $18) 69... Ke3 70. Kh4 (70. g5 {is no longer good enough. Ex:} Ke4 (
70... Kd4 $2 71. Kf4 hxg5+ 72. Kxg5 Ke3 73. Kf5 Kf2 74. g4 Kg3 75. g5 Kh4 76.
Kg6 $18) (70... h5 $2 71. Kh4 g6 72. g4 hxg4 73. Kxg4 Ke4 74. Ba2 Ke5 75. Bf7
$18) (70... hxg5 $2 71. Kg4 Kf2 72. g3 Kg2 73. Ba2 Kf2 74. Bd5 Ke3 75. Kxg5 Kd4
76. Ba2 Ke4 77. Kg4 Ke3 78. Bb1 Kf2 79. Kf4 Kg2 80. Ba2 Kf2 81. g4 Kg2 82. g5
Kh3 83. Kf5 Kh4 84. Bb3 Kh5 85. Be6 Kh4 86. Kg6 $18) 71. Kg4 Ke5 72. Ba2 Ke4
73. g3 Ke3 74. Bb1 Kf2 75. g6 h5+ 76. Kxh5 Ke3 77. Kg5 Kd4 78. Kf5 Kd5 79. Ba2+
Kd6 {and Black has succeeded in securing the draw.}) 70... Kf2 71. Bd5 (71. Kh5
{fails because the white bishop is overwhelmed after} Kxg2 72. Kg6 Kg3 73. Kxg7
a2 74. Bxa2 Kxg4 75. Kxh6 $11) 71... g6 72. Kh3 g5 $1 $11 {White cannot leave
the kingside without losing the g4 pawn.} 73. Kh2 Kf1 74. Be6 Kf2 75. Bc4 Ke3
76. Kg3 Kd4 77. Be6 Ke3 78. Kh2 Kf2 79. Bc4 Ke3 80. Kg1 Kf4 81. Be6 Ke5 82. Bb3
Kf4 83. Be6 Ke5 84. Bb3 Kf4 85. Be6 Ke5 86. Bb3 1/2-1/2


Joining a FIDE tournament abroad without a rating

Often tournaments have a B- (or C-) open in which even unrated players can take part.

But I have also encountered the regulation that unrated players need to provide an estimate of their playing strength, given by their federation, to take part in an open. Maybe that would be an option for you.

Apart from reading tournament regulations carefully you can always just write to the organisers explaining your situation. They should usually be quite accommodating, and if they aren't maybe this shouldn't be the tournament of your choice anyway.


How can minimax chess engines do alpha-beta pruning without reaching the final positions?

If a chess engine isn't aware of the mate, then it will be happy to play the moves as Black. By the time it sees the checkmate, it'd be too late. Game over. 1-0.
Fortunately, your scenario is quite simple. A good engine should have sufficient depth to see the mate. The iterative deepening depth-first algorithm will allow searches with increasing depth limits: d,d+1,d+2,d+3... I believe any decent chess engine should be able to handle it, it's not a very deep search.
While your example is simple, pruning does cause problems for tactical positison. Take a look at Chessbase's article:

https://en.chessbase.com/post/houdini5tacticalmode
...Suppose there is a complicated position in which you just feel there must be a tactic. You could be right, but sometimes even the monster engines can miss it at first...

"Tactical mode" is a fantasy term for applying passive pruning.


Chess challenge #7: Women's European Team Championship

I think the winning tactical combination is the following:

   1.Qh5! h6 2.Bxf7+ Rxf7 3.Qxf7+ Qxf7 4.Nxf7 Kxf7 5.b4 Nxe4 6.Rd7+


How would you figure out someone's Elo rating from a single game of chess?

I also try to take part in that competition, although I'm not sure I will be able to spare the time and computational effort to actually make a submission.

Unfortunately I think the Kaggle data set of engine evaluations isn't suitable to get the best possible result. I think it is crucial to not only have the evaluation of the best move, but also of the inferior choices.
The reason is that you need to calculate some kind of measure of the complexity of the position to weight the accuracy shown by the players.

In short: It is hard to be accurate in a complex position and easy to be accurate in a simple position.

Another problem is that at a runtime of one second per move, stockfish probably isn't much stronger than the average player in the dataset (which would be around 2200 Elo) …

So to create a decent dataset one would have to invest a lot of cpu-hours. 50000 games x 40 moves x 1second (or more) >= 555 hours.

To create an opening tree that allows you to see when the players deviate from already played games and how strong the players of the played games were, is another idea to give an initial guess of the players strength.

So my rough outline is to create an opening tree to get an initial guess of the strength, ignore the moves played in the opening, weight the accuracy of the moves after the opening phase with the complexity of the position and do some kind of linear regression analysis. Maybe look out not to overvalue time trouble blunders.

I think the key is to get a good "complexity number". The other possibilities you mention … "number of blunders" just reduces "accuracy of play" to something similar with less information. "Depth of tactical traps avoided" is tricky and may computationally be even more expensive.


Chess players identify with their openings, all chess clubs have that one guy who always plays stodgy London stuff with white, the maverick with all his dodgy gambits and the youth player with 25 moves of Najdorf theory memorized for the day he finally gets to play it.

Opening books are by far the most sold type of chess book, and the number of titles is much larger than that of other types of book. People write hundreds of pages of grandmaster level analysis on a line that starts on move 6 and still lots of amateurs buy the books.

When an amateur watches a grandmaster game live, he uses knowledge of the opening played to understand what is going on. If they play a King's Indian and the center is locked, one of them is going to attack on one wing and vice versa. If it's a closed Ruy Lopez, we know there's probably a slow maneuvering game coming up, et cetera.

Playing memorized opening theory gives the amateur the feeling that for that part of the game at least, he is playing at grandmaster level.

In other words, chess players like opening theory.


Depends if you have the white pieces or the black pieces;

white: 1. Nf3 - Versatile, deceptive, unassuming. Typically, blacks first move dictates the style and nature of the game. However, with 1. Nf3, white has countless systems at his disposal depending on how black responds.

b3 (Nimzovich-Larsen attack)

g3 (King's Indian attack)

c4 (English opening)

black:
against e4: 1... Nf6 - Alekhine's defense. From move number one, black is directly attacking white's center. Many novice players will over-extend themselves and start pushing their pieces hastily. Alekhine's defense is a tricky, formidable response to 1. e4, as Bobby Fischer showed us in 1972 against Boris Spassky.

against d4: 1...f5 - Dutch defense. The Dutch defense, whose famous practitioners include  Aleksander Alekhine, Mikhail Botvinnik, and Hikaru Nakamura, is a dangerous response to 1. d4. Black is taking dead aim at white's kingside and, specifically, the e4 square.


Is it bad etiquette to try to make an opponent lose on time when a position is clearly drawn?

Etiquette doesn't really come into it unless your name is Gata Kamsky (strong language warning for the link). The rule is very simple. If you want flagging to be a part of the game then play with no increment, otherwise always play with an increment.


Chess pairing program for double round robin

Just use the "Berger" Pairings/Tables. If there are an odd number of players, then a "dummy" player is added. When creating the pairings each round, whoever is playing the "dummy" player is simply receiving a bye. Then you run it again with colors reversed. If your program has no major issues, you should be able to manually enter people into your program, and the program should allow for people to be paired again with reversed colors.


Checkmate is possible with a king, bishop and knight against a bare king, and therefore it would have been a win for white if you timed out before the 50 or 75 move rules came into play. So for instance if the game had gone 72 ... Qxh3 73 Bxg3 and then you timed out within the next 50 moves it would be a win for white.


What is the theory behind Bishop's Opening, Philidor Counter-Attack?

Black cannot play Nc6 at the moment, that is true. However, it doesn't look like White can exploit this immediately, either.

Black will answer 3 Nf3 by ...d5, gaining tempo on the Bc4 that he can then use to either defend e5 (d7 is open for the knight, at the very least) or counter-pressure e4 (which is equally weak as e5). The whole motive is similar to the classical center attack in the Italian (c3 + d4).

Trading the pawns (4 exd5 cxd5) opens c6 for the knight again and doesn't look very attractive as it yields the center to Black. 5 Bb5+ is toothless, Black will reply ...Bd7 and then take back on d7 with his knight (or simply play Nc6 if the white bishop retreats now). Immediately retreating (by 4 Bb3) doesn't look very good either, Black will gain the initiative.

Of course, White has other options for his third move. 3 d4 is a similar attempt to attack e5. Black can reply 3...d5 again, which leads to a very complicated position. But again, e4 is just as weak as e5 and swapping away e4 opens c6 for the knight. No clear advantage for any side.

Against 3 Nc3 (prevents 3...d5, but doesn't attack e5), Black has time to play 3...Bc5 , followed by 4...d6 (e5 is safe) and he will achieve something similar to a Giuoco Pianissimo Reversed - which is not too bad, really.

So, yeah: Totally playable in my opinion.

Disclaimer: I'm not an actual expert in this opening.


I don't think 1.d4 itself really makes the game slower; you can use 1.d4 to play aggressive chess. Kasparov and Alekhine did. Likewise, you can play positional chess with 1.e4, e.g. Ruy Lopez, (especially Karpov's handling of it).

So if you want to practice positional chess you don't need to switch to 1.d4, and if you switch to 1.d4 without changing your mindset, you won't necessarily be playing positional chess.

I first tried 1.d4 after playing for about a 1 year. I was really fascinated with the Qd3 and Bc2 (or Bb1) set up and tried to drive away black knight form f6 and mate on h7, basically my whole plan revolved around that. I didn't find 1.d4 much harder to play or anything like that, but I am sure you are a stronger player than I was back then :).


Stockfish thinks 1. Rc1 leads to a even game or maybe a draw. It's undone immediately by 1. ... Ba3.

Stockfish preferred 1. Nh4 with a 60 centi-pawn advantage to White.

[FEN "2kr1b1r/pp3p1p/1q2pp2/3p1b2/3P1B2/1PP2N2/P4PPP/R2QR1K1 w - - 0 1"]

1.Nh4 Bg6 2.Qf3 Be4 3.Qh5 Rd7 4.Rad1 Rg8 5.c4 Bb4 6.Re3 Qc6 7.Qe2 Bd6 8.Bxd6 Qxd6 9.f3 Bg6 10.c5 Qf4 11.Nxg6 hxg6 12.b4 Qc7 13.b5 Kb8 14.Rb3 b6 15.Qe3 g5 16.Rc1 Qf4

The 1. c4 move fares ok at about 40 centi-pawns but by the end any winning chances look like an illusion.

[FEN "2kr1b1r/pp3p1p/1q2pp2/3p1b2/3P1B2/1PP2N2/P4PPP/R2QR1K1 w - - 0 1"]

1.c4 dxc4 2.Rc1 Bd6 3.Bxd6 Qxd6 4.bxc4 Rhg8 5.d5 Qf4 6.g3 h5 7.Nd4 h4 8.Nxf5 Qxf5 9.Rc3 exd5 10.cxd5+ Kb8 11.d6 Qd7 12.Rc7 Qxd6 13.Qxd6 Rxd6 14.Rxf7 a6 15.Ree7 b5 16.Kg2 hxg3 17.hxg3 Rgd8 18.Kf3 Rd3+ 19.Kf4 Rd2 20.Rb7+ Ka8 21.Ra7+ Kb8 22.Rxa6 Rxf2+ 23.Ke3 Rg2 24.Rb6+ Kc8 25.Rxb5 Rxa2  (964.21)


Let's face it (and this is not being mean), both players are beginner chess players and are naturally making lots of mistakes. For instance 7....Qa5+ would win the knight on e5. Also black had a forced mate starting with 14. ... Rxf2+ (with the idea to remove the pawn first which could intercept bishop checks) but chose to win the queen instead.

Of course 12. Qxg7 was a losing mistake because after 12 ... Rg8 you will lose the queen (or the game if you let black take on g2). You could call this a mini-trap, but more typically you would call the pawn on g7 poisoned pawn, because it kind of obviously should not be captured because of the resulting attack on g2.

It is well worth memorizing the pattern of Nf6, Qg7, Rg8 as you will encounter it in many games, in all four corners of the board (i.e. also with queens on b7, b2, g2). Also note, that in this setup the square/pawn h7 is protected, leaving the queen only one square to escape. So, if you memorize this pattern  you should memorize it together with two ideas: i) the rook might attack something along the g-file (or b-file if in other corners) and ii) the queen has little space (and in other situations that one escape square might not be available; e.g. occupied or under attack).

I don't think this pattern/"trap" has any specific name. After 13. Qh6 Rxg2+ 14. Kh1, white runs into a discovered check which is very often deadly.

Apart from the forced check mate after 14...Rxf2+, you could also consider this as a mini windmill, i.e. you could win an extra pawn (on f2) in addition to the queen. But note that black cannot continue with the windmill (winning pawns on c2, b2, a2) because white can cover the bishop check with Rf3 and escape with the king to f1.


The point of the minority attack, you have correctly pointed out, is to force pawn weaknesses. Usually, the weakness that you are going for is to create a backwards pawn. This weakness is very difficult to deal with for your opponent. Normal play is to gang up on the pawn, double your rooks along the file.


Longest *shortest available* fixed sequence of moves leading to checkmate?

In other words, you wish for the record length for a completely dual-free sequence. Every White move must be absolutely unique to any possible by Black. Shorter, dualed mating sequences do not count.
To that end, I remembered a mate in 61 from this page on SuperProblem.ru (a Russian based chess problem site). It is also in the Die Schwalbe Chess Problem Database.
[Title "Bosko Miloseski, SuperProblem.ru 1/24/2020, Dedicated to the participants of TT-235, Mate In 61"]
[FEN "4Q3/1ppr4/br1k4/1p1p4/1PpP1p2/KBp2p2/2P2P2/8 w - - 0 1"]

1. Qe5+! Kc6 2. Qe6+ Rd6 3. Qe8+ Rd7 4. Ba2 Kd6 5. Qe5+ Kc6 6. Qe6+ Rd6 7. Qe8+ Rd7 8. Bb1 Kd6 9. Qe5+ Kc6 10. Qe6+ Rd6 11. Qe8+ Rd7 12. Ka2 Kd6 13. Qe5+ Kc6 14. Qe6+ Rd6 15. Qe8+ Rd7 16. Ka1 Kd6 17. Qe5+ Kc6 18. Qe6+ Rd6 19. Qe8+ Rd7 20. Ba2 Kd6 21. Qe5+ Kc6 22. Qe6+ Rd6 23. Qe8+ Rd7 24. Kb1 Kd6 25. Qe5+ Kc6 26. Qe6+ Rd6 27. Qe8+ Rd7 28. Kc1 Kd6 29. Qe5+ Kc6 30. Qe6+ Rd6 31. Qe8+ Rd7 32. Kd1 Kd6 33. Qe5+ Kc6 34. Qe6+ Rd6 35. Qe8+ Rd7 36. Ke1 Kd6 37. Qe5+ Kc6 38. Qe6+ Rd6 39. Qe8+ Rd7 40. Kf1 Kd6 41. Qe5+ Kc6 42. Qe6+ Rd6 43. Qe8+ Rd7 44. Kg1 Kd6 45. Qe5+ Kc6 46. Qe6+ Rd6 47. Qe8+ Rd7 48. Kh2 Kd6 49. Qe5+ Kc6 50. Qe6+ Rd6 51. Qe8+ Rd7 52. Kh3 Kd6 53. Qe5+ Kc6 54. Qe6+ Rd6 55. Qe8+ Rd7 56. Kg4 Kd6 57. Qe5+ Kc6 58. Qe6+ Rd6 59. Qe8+ Rd7 60. Kf5 Kd6 61. Qe6#

This works since Black basically has only one legal move for the entire mating sequence. There are no alternative lines that might spoil it with White dual mates and such.


Has a highly-rated GM ever lost to a low-rated opponent who didn't go on to become a GM?

There is a book called "Great Chess Upsets" by Reshevsky, but unfortunately most of the games are not upsets at all, but one famous player against another. Reshevsky himself, in his first major tournament, beat Janowski even though he was prepubescent. Prior to the tournament Janowski bitterly complained to the organizers that they were spoiling the gravity of the event by allowing children to play in it. After he won, Reshevsky reporting starting jumping up and down shouting, "I beat a grandmaster! I beat a grandmaster!".

Some of the more notable upsets:

In 1905 Frank Marshall, a World Championship candidate, lost to the unknown Dutch player Dirk Bleijkmanns at the Scheveningen Masters Tournament.

Joel Fridlizius beating both Alekhine and Spielmann at the Nordic Masters Tournament in 1912.

At the great St. Petersburg Tournament of 1914, the winner, Alexander Alekhine lost to German lesser light Bernhard Gregory.

In the 1923 Scheveningen Match Tournament, Spielmann lost to the little known Dutch master George Fontein.

In the 1924 Masters Tournament in Merano, Rubinstein lost to unknown player Gyula Patay.

Max Euwe lost to Vera Menchik at the 1930 Hastings Tournament, thereby becoming a member of the "Menchik Club".

The Cuban master Guillermo Estevez Morales beat Mikhail Tal after Tal blundered the exchange.

Croatian master Josip Rukavina beat Korchnoi at the 1973 Interzonal.

The unknown Ecuadorian player César Muñoz beat Bobby Fischer at the 1960 Leipzig Olympiad.

Bernardo Wexler beat Fischer at the 1960 Buenos Aires tournament.

An unknown player named Robert Burger beat Bobby Fischer in 12 moves in a simul after Fischer fell into a surprising trap of the queen.

Israeli Alexander Huzman beat Kasparov in the 2003 European Clubs Cup in 24 moves after Kasparov blundered two pawns because he missed a mate threat.


Playing good chess is still totally worth it. It's much easier to blunder in a deseprate position than in a good one. That being said, the main path towards stopping blunders is improving your tactical skills so you can detect threats more easily.
With enough time on the clock, you should always look for forced moves both you and your opponent may have (checks, captures, mate threats...) There's probably a reason for your opponent's last moves, so think of what new threats it creates.


What should be the next move in this position?

All black pieces are currently defended but that does not mean there is nothing to do as if you play aimlessly white will eventually gain an advantage.
On analyzing the game the first thing you can notice is that the kingside is completely locked down by pawns so our attack needs to be on the queenside. Ba6 and Be7 are good moves to start gaining control on the queenside. Double rooks on c- file with a c5 pawn break is one option (but it sacrifices the d5 pawn).
Exploiting White's cramped position is essential for any strategy you employ on the queenside side. White will probably outpost his knight on the f4 square so BxN eventually will open up the e-file. Even though this is a drawish game it is far from over and inaccurate play from either player might lose the game.


Is chess a good game for recovering addicts?

Stack Exchange has a site dedicated to medical sciences.
If you open that, you'll immediately see that on the right column there's a disclaimer that you won't find on any other Stack Exchange site. It's a bit long, so let me cut the most important parts:

Stack Exchange Inc., and its sites including Medical Sciences Stack Exchange, is not a medical practice or healthcare provider and does not provide medical advice.
[...]
Consult your own doctor for medical advice.
[...]
Medical Sciences Stack Exchange is for information exchange only, and is not a substitute for medical advice, individualized diagnosis or treatment by a healthcare provider.

This obviously covers the legal aspect, but it's more than that. Even if there were no lawyers and lawsuits in this world, that disclaimer would still have value. Because, well, it's true. In general you cannot trust users on any of these sites to really know what they are saying. Your health is too important to blindly trust some random stranger on the web, no matter how high their reputation is or how sincerely they are trying to help.
Besides, it seems to me that you've already got the answer from your clinic:

But they banned me from chess, arguing I played obsessively.

I'm sorry, but I'm afraid you'll have to accept it.
I hope I won't sound judgmental if I tell you that what you are really doing here is not looking for an answer (you've already got one; only, it's one you don't like), but rather for an excuse that will let you keep playing and ease your conscience.
Imagine someone posted an answer along the lines of

Don't worry, those doctors don't understand anything! Playing chess can't be a problem, just go ahead and play as much as you want!

I suppose you'd be very happy to read it. And yet, who would you rather trust: the doctors that visited you and know your case specifically, or someone who probably has no idea what they are talking about, and who certainly doesn't know you, your clinical history, anything about you at all?
So do the right thing, and do what your doctors say. Or in any case discuss with them what you should do.
My best wishes for your full recovery!


How to change text color in Arena Chess?

It seems that in Arena some colors are controlled by the operating system. I went to Control Panel\Appearance and Personalization\Personalization, clicked on Window Color and in the Window Color and Appearance I changed the color of the item Window to green in order to make it easier to see the color changes in Arena.

And this is the result.

As you can see, some text remained black, like:

RAM display (next to the Appearance Settings button)
players' rating
numbers inside the Permanent Statistics pane
last player move (to the right of opening name)
the Demo button

I don't know how to change the color of these elements.


Typical Good Bishop vs. Bad Bishop endgame - how to decide if stronger side has a definite win

With new analysis from user AlwaysLearningNewStuff, we can conclude this is a win for white,

The first critical position appears after 1.Be2 Kb7.

      [FEN "2k5/5b2/p7/P1p2p1p/P4P1P/2K2B2/8/8 w - - 0 1"]

       1.Be2 Kb7

Black defends everything at the moment, but the only moves that keep the position are Kb7-a7-b7. A simple triangle maneuver puts black in zugzwang.

     [FEN "2k5/5b2/p7/P1p2p1p/P4P1P/2K2B2/8/8 w - - 0 1"]

       1.Be2 Kb7 2.Kd2 Ka7 3.Kc2 Kb7 4.Kc3

Now black is in zugzwang and loses. The following lines illustrate this:

[FEN "2k5/5b2/p7/P1p2p1p/P4P1P/2K2B2/8/8 w - - 0 1"]

1.Be2 Kb7 2.Kd2 Ka7 3.Kc2!+- Kb7 4.Kc3 ( 4...Ka7 5.Bc4 Be8 ( 5...Bg6 6.Be6 Kb7 7.Kc4 Kc6 8.Bd5+ Kd6 9.Bb7+- Bf7+ 10.Kd3 )( 5...Bxc4 6.Kxc4 Kb7 7.Kxc5+- ) 6.Be6 Bg6 7.Kc4 Kb7 8.Kxc5+- )( 4...Bg6 5.Bf3+! Kc7 6.Kc4 Kd6 7.Bb7+- Bf7+ 8.Kd3 )( 4...Be8 5.Kc4 Kc6 6. Bf3+ Kd6 7.Bb7+- Bf7+ 8.Kd3 ) c4! 5.Kd4! ( 5.Bxc4? Bxc4 6.Kxc4 Kc6= ) 5...Kc7 ( 5...Kc6? 6.Bxc4 Bxc4 7.Kxc4+- )( 5...Kc8? 6.Bxc4+- Bxc4 7.Kxc4 Kc7 8.Kc5 ) 6.Bf3! Kc8 7.Bd1!!+- Kc7 ( 7...Kd7 8.Bc2! Be6 9.Ke5+-)( 7...Kb7? 8.Bc2! Be6 9.Ke5 Bd7 ( 8... Bg8 9.Bxf5+- ) 10.Kd5!+- ) 8.Bc2! Be6 9.Ke5 Kd7 ( 9...Bd7 10.Kd5!+- ) 10.Bd1! Bf7 11.Kxf5 Kd6 12.Kf6!+-

The important idea is that after 4...c4! White uses 6.Bf3! to restrict Black king. After 6...Kc8 White repositions Bishop on c2 with the move 7.Bd1!! so the decisive zugzwang can be achieved. After 12.Kf6! the rest is a matter of technique.

The analysis is kept as brief as possible in order to preserve space, since the rest of the winning moves can be easily found with an engine.


Lichess Puzzle 82753: Can white win with a queen and two pawns vs. rook and four pawns?

It looks very difficult for white to prevent the fortress.

The obvious sequence is something like -

[FEN "2Q5/6p1/1K3pkp/8/8/4p3/r5PP/8 b - - 0 1"]

1. ... Rb2+ (to kick the king one square further from the action) 2. Ka5 Rxg2 3. Qe8+ Kh7 4. Qe4+ Rg6 5. h4 h5 and black has 3 extra pawns, albeit the e3 pawn is likely to fall soon

If 5. Qf5 then 5... h5 anyway when 6. Qxh5 Rh6 leaves white struggling to save the h pawn.


Touch-move when move is illegal but opponent's piece can be captured by another piece

Article 4.3.2 clarifies this -

  4.3 Except as provided in Article 4.2 [j'adoube], if the player having the move touches on the chessboard,with the intention of moving or capturing:

  4.3.2 one or more of his opponent’s pieces, he must capture the first piece touched that can be captured

In the scenario you describe you touch your knight and your opponent's bishop with the intention of capturing the bishop with your knight. Moving the knight is illegal hence you may not capture the bishop with the knight. However capturing the bishop with some other piece, your queen, is legal. Therefore you must capture the bishop with that piece.


Is it possible to improve the Elo rating system like this?

Sure, you could compress the current range like that. The issue, though, is that ELO is not an objective scale with absolute endpoints. It's only a measure of play strength relative to past opponents.

The fact that no current player has an ELO above 2900 does not mean that such ratings are impossible. Until 1990, no one had a rating above 2800. In fact, there's no mathematical upper bound on ELO rating at all: see this question, for example. The "big range of [unused] numbers" is infinite.

So yes, you could compress the ratings--but what do you do when someone achieves ELO 3001 in the uncompressed system? Recompress it with a different scaling factor, and change what everyone's ratings mean? And keep doing this every time someone "breaks" your current system? If the goal is to make ELO simpler to keep track of, this seems rather counterproductive. I suppose you could report log ELO to make it more tenable (also sillier), but the fact remains that there's no mathematical bound, so there's no guarantee that all ELOs will stay within the range you're looking for.

Perhaps the most pertinent question of all is, why? What do you gain from compressing Elo down to three (ish) digits? It diminishes (slightly) your ability to distinguish between players of similar ratings, but what is the upside? Or, why not compress it down to between one and one hundred, or zero and one? It's all the same values; "three digits" is quite arbitrary, and I can't think of any way that it "improves" on the current system.


What is White's compensation in the Smith-Morra Gambit, Paulsen Formation (a6, e6, Nc6) after an early ...Na5?

To be honest, I see very little there, but Re1 also just looks like it is not in the spirit of the opening since it does little to add any pressure to the center. Of course, if black were to play d5, then it would make sense, but black will probably refrain from playing that for quite a while. Bc2 probably should be played there, and follow it up with the standard Qe2 and Rd1.

Overall, the only compensating factors right now are a slight lead in development, and more space; but as always, in such positions, if the other side is very solid, they can catch up in development, and then the extra pawn will become a major factor.

There is a reason the Morra is only popular at lower levels: It just loses a pawn, and there are not many redeeming factors.


What would approximately be the ICCF rating of a GM with no external help and of a computer with no human judgment?

I play on ICCF. My guess is that the engineless GM might be able to maintain a 2000 rating by beating other engineless players or players who are bad at engine use.

I don't think the second player would do that well actually. Players in the 2300+ range are all using anti-engine strategies, following GM opening theory, have their novelties, so they can lure him into opening traps or positions his engine has trouble evaluating. I would guess he'd wouldn't go much beyond 2100.  I've played against 2200 players who are pure engine once out of book, but they put more effort into their openings than your player B does.

There is another breed of player you haven't mentioned: the engine monkey master.  These are players with 2000+ ratings over the board. They could potentially try to carry out strategic plans in the middlegame, but they get so caught up in the engine analysis they end up play positionally suspect moves. They do contribute a lot to the openings and endings though, so you see them in the 2300-2400 range.


What are some lines of the Queen's Gambit symmetrical variation for white?

It's really unknown, I've never seen it actually played except for maybe one or two internet blitz games out of ten thousand. But I've looked up some lines for you.

You play 3.cxd5 and now black needs to decide what to do.

The symmetrical 3...cxd4 4.Qxd4 followed by e4 just loses a pawn.

3...Qxd5 allows white to chase the queen, getting a lead in development:

[FEN ""]

1.d4 d5 2.c4 c5 3.cxd5 Qxd5 4.Nf3 cxd4 5.Nc3 Qa5 6.Nxd4

So black plays 3...Nf6. Now a thing like 4.Nf3 cxd4 5.Qxd4 Qxd5 stays completely symmetrical, but white can play 4.e4!.

Fundamental Chess Openings gives two lines, both a bit better for White because of better development:

[FEN ""]

1.d4 d5 2.c4 c5 3.cxd5 Nf6 4.e4 Nxe4 5.dxc5 Nxc5 6.Nf3 e6 7.Nc3 exd5 8.Qxd5

and

[FEN ""]

1.d4 d5 2.c4 c5 3.cxd5 Nf6 4.e4 Nxe4 5.dxc5 Qa5+ 6.Bd2 Nxd2 7.Qxd2 Qxc5 8.Na3


Difference between Swiss Manager Light and Full version?

The difference is in the scale of the tournament / match you need to handle. If you plan a tournament with maximum of 60 participants and 11 rounds (or a team championship up to 6 teams), the light version is enough.

If you plan to grow big, then choose the full version.

You can read this on the official site (last paragraph).


So, for future reference, the option is under: Edit -> Setup Start Board..., or by pressing S.

Update: There is another way! Click on the 'menu' icon below the board (three horizontal bars), then on the what I see as a 'crop' icon (on the far right), and then following menu pops up:


Is there a method to efficiently generate moves for bishops?

Move generators in modern engines do this with lookup tables, which are indexed by the square of the slider and a bitboard representing occupied (impassable) squares that might block the movement of the piece.

There are two main ways of compressing the huge set of possible occupancy bitboards into a reasonable size. Magic Bitboards are often used, which involve multiplying the occupancy bitboard by 'magic' numbers, which are chosen because they empirically map the set of possible occupancy bitboards into a dense range.

A more modern way depends on the PEXT instruction which is available in newer x86 processors. PEXT bitboards allow for the lookup table to be mapped to an even denser range, and also improves lookup times on processors which can run PEXT quickly. However, PEXT is very slow to emulate on older processors, and also seems to be particularly slow on Ryzen processors.


Dr. John Nunn vs Irving Chernev's "Logical Chess Move by Move"

It seems that Nunn (who is undoubtedly a stronger player than Chernev was) is correct in his criticisms of certain instances of analysis in Chernev's book, and also correct in pointing out that Chernev is sometimes too quick to dogmatically conclude an overarching general principle that doesn't properly allow for exceptions. But I don't believe this should cause you to read Chernev's book with caution (at least no more caution or skepticism than one should have when reading anything), and certainly not with paranoia.

The criticisms Nunn directs Chernev's way in Grandmaster Chess Move by Move are worthwhile things to hear for a player who is at an appropriate level to be reading Nunn's book, but the intended audience for that book is quite a bit more advanced than is Chernev's. The fact that Chernev makes certain oversimplifications (and yes, out-and-out mistakes in some places) is a good thing to be discovered at some point in a player's chess development, but this doesn't necessarily mean that Chernev's book, warts and all, cannot be (very!) useful to a beginner. [Consider: an absolute beginner reading Nunn's criticisms of Chernev that you cited wouldn't be able to appreciate the points being made at all: they would sail right over his or her head.]

The saying "One has to know the rules to break them" is applicable here. If you were to try and take every word in Chernev's book as gospel for the rest of your chess career, you would indeed be leading yourself astray. The same would be true if you tried to dogmatically follow, say, "knights should be developed before bishops" or similar overly general advice which is routinely thrown at novices. That doesn't mean that that kind of advice doesn't serve a useful purpose by giving newcomers to the game some first, rough guidelines to start learning from. I think the same can be said for Chernev's work; after all, it's not for nothing that this instructional book from 1957 is still topical today.


No, it is not.

FIDE Laws of chess, clause 3.7e:

  When a pawn reaches the rank furthest from its starting position it
  must be exchanged as part of the same move on the same square for a
  new queen, rook, bishop or knight of the same colour.


Chess.com's daily problem-Why doesn't 1...Nf8 win the Nh7?

Frankly, you overlooked a major detail...Nf6+ in reply is mate. It is important to notice your "opponent's" moves too.

 [FEN "r2qk2r/pp1nnp1N/4p1pQ/3pP3/4b1PP/P1B5/1PP1B3/R3KR2 b Qq - 0 1"]

 1... Nf8 $4 (1... Ng8! 2. Qg7 (2. Nf6+ Qxf6 $1) 2... Qxh4+ 3. Kd2 Qxh7) 2. Nf6#


Even one minor error could cost the game against a perfect opponent, so 95% losing rate is generous.  However, I don't understand how the "best move" engine could lose any games in the second trail.

The ABSearch could be modified, but it's easier to perform this at the RootSearch function.  Since the arrays for the current moves and their respective scores are present here, it's easy to implement, and the RootSearch should be able to self-correct on future moves better than anything done in the current ABSearch.  (This is really messy.  Sorry.)
I've seen three ways to limit strength.

a.  Make a weak move at a specific interval.  When playing against its sponsors, a computer was told to make a random king move every 10 moves.

b.  The computer wasn't allowed to make a move in which the eval was above a threshold.  So, for a drawing computer, the computer wouldn't make a move where the eval was above a pawn or had to make a mistake to lower the eval to below this range.  This i similar to your variance, but instead of within the top range, it's a final eval of +- a pawn.

c.  The chess engine Galahad (I can't find its source anymore.) allowed you to change some eval constants.  Lowering the penalty for a weakness, such as doubled pawns, does lower its strength, but not in a dramatic manner.

Trappy Beowulf trys to implement a more human engine where it does try for traps instead of the best move.  I haven't read the code, so I can't explain how it accomplishes this, but I assumed that it goes for simple, one move threats, and when this threat is parried, the positions is slightly worse.

I"d like to give a special thanks to the four examples and the OP for thinking out of the box.  Not just trying to be the best, but for being usable.

EDIT:  A better example is "c" would be a piece-square value.  By adjusting this variable, you could make the computer think that g3 is a better square for the knight than e5.  This could be used to make the computer decentralize pieces or make them more defensive.  Changing the pawn protection around the king values, you could make the computer make these weakening moves and test your attacking skills.  The options are only limited by your imagination.


How many positions per second should my homemade engine calculate?

On my old laptop with an i5 processor, running on a single thread, a recent version of Stockfish (written in CPP) makes around 1 million nodes per second (1Mnps). You must take into account that these nodes are not just the move generator, but the engine is also using its evaluation, so Stockfish's move generator should be much faster than that
My very simple chess engine (written in C), whose move generator is not optimized can make around 4.5Mnps also on a single thread (with no evaluation, just the move generator working. This is what in chess programming is called a perft test).
So at first glance something like some thousands of positions per second seems like very poor performance.
Of course part of this poor performance can be due to the language you've chosen to write your engine, but unless you've made a really weird choice, it seems like there's something odd about your program. My educated guess is either the move generator is buggy or its design is (very) sub-optimal.


For Windows desktop there is ChessX and for a modern / metro app there is PgnViewer


What is the required Elo to beat a Grandmaster with queen odds?

I have a hard time believing that there's a player on the planet who could beat me with Queen odds.  The strategy would be simple: trade off pieces pieces when possible.  I'm a USCF B player.

Here are some 'Queen Odds' games.  Play by the weak side is sometimes very dicey. Paul Morphy loses his game.  None of the games the GMs won went past 15 moves.  After that the Queen asserts too much power to overcome.

Here's a rant, lol.


Can Black perform a successful freeing break? If yes, what would be his long-term plan after?

c5 is, by far, the preferred idea and line here, because it not only frees up the light squared bishop, breaks and challenges the d4 pawn, as in some Rubinstein lines, but also allows your queen to visit in e7, and park your rooks on c8 and d8 respectively.

It is by far, in terms of breaks, the most effective, and does not allow white the luxury of a kingside attack.

Therefore, as white, it would be beneficial, tactically, to park your a-rook on d1 to prevent c5 and then try to play on the d-file with doubled rooks and c3 (to prevent counterplay).


How or what to practice when mentally exhausted?

Yoga.

Failing that watch your favourite TV programme.


f5 is a decent square for your knight, but it is not doing all that much from there either. Ok, it is attacking d4, but that pawn is overprotected by knight and queen, so nothing to worry about for white.

I am not a Caro-Kann player, but I believe a much more natural plan is trying to push c5 exchanging the d4 pawn after which the pawn on e5 gets weak.

Even if you get in Nf5 first, I don't see how you would proceed without playing c5 as black.

Regarding the move h5. Yes it does prevent g4 for the moment, but it also weakens the square g5, which can be occupied by white knight and bishop. For instance after h5 castling short is almost impossible for black, because after white Ng5, Qh7 mate is very difficult to prevent.

After Ne7, immediate g4 is not good, because

it weakens the white king
it only prevents Nf5 which is not all that dangerous anyway (see above)
if you want to prevent the black knight from occupying the square f5, you could just wait until black moves Nf5, then play g4 and you would gain a tempo, because the knight would have to retreat to e7.


To earn a direct title for coming first in an official FIDE tournament, do we include players who already have that title?

Yes, we include all the players who participated in the event. If you finish second after WGM Ryjanova, you will receive a norm but not the title. If you finish fourth, you receive neither, regardless of who is on the podium. If the level of the field is high with a lot of tilted players participating, it often occurs that no 'special' title is awarded at the end of the tournament.

For instance, the World Junior champion is awarded with a grandmaster title. This year, the tournament was won by Iran's Parham Maghsoodloo, who was already a GM. The first non-GM in the tournament, IM Sergei Lobanov, did not receive that title instead (he 'only' got a GM-norm for his third place).


Before I answer I'm sorry if my english is bad. This game opening using King's Gambit declined (C30). I make the assumption that you are aggressive player who like open game than close game based on your opening and moves. In my opinion the several your mistakes and blunders is:

5.h3; the best move is 5.d5. Why d5? Because you can push your opponent knight and you winning the center position. If your opponent play 5...Nd4, you can counter with 6. Be3 Nxf3+ 7.gxf3 exf4 8.Bxf4 Bd7 9.Nc3.... You absolutely win the center and have a pole position to develop your pawns and pieces
7.Bc4; Black move in 6...Nf6 is mistake, 6...Nd4 is better than 6...Nf6 because he can push your Queen. But you counter with Bc4, the move that you should take is 7.Bb5 because you can freeze your opponent knight. If your opponent moves is 7...exd4, you can counter with 8.0-0 and makes your opponent pawn hanging in the center
8.f5, Black move in 7.Qd7 is bad, but your counter move 8.f5 is bad too, you can counter with 8.d5. You will lost your pawn in the center if you take the other move than 8.d5
11.c4, In my opinion, black move in 10...h5 is not good. I don't know what his plans but he should take 10...c5 to backup the knight in d4 and can push your Queen and Bishop. Your move should 11.0-0 make your King safer than before. But Black made a mistakw again with 11...Rb8. He should take your pawn in c4 and next move maybe 12.Qxc4 d5 13.exd5. He make your f5 pawn hanging.
13.Nb5. It makes your bishop in b3 taken by Black knight
14.a4. Maybe it's your biggest mistake in this game. Your opponent 13...Rb7 is bad move. You can obtain his knight in d4 with your knight and next move is 14...exd4 15.Qxd4. You got his pawn in center!!!!
15.0-0. Black second biggest mistake is 14...g6??? He can focus in his right side(A-D) and push your pawn. The best Black move is 14...Nxb3. Your counter is  very bad. You should still take the 15.Nxd4 move.
16.Qd1. And this is your biggest mistake too. You are lead the game if you take 16.Nxd4 move. 3 move and maybe you still don't realize this is your greatest move so far in this game
17.Rxf5. Another biggest mistake too. 4 move and still don't realize.
20.Qc1. 20.Qf3 is better
22.Qh8+. 22.Rf1 is better
23.c5. 23.cxb5 is better

This is my analyze. I'm sorry if I made a mistake too in this analyze


sets up for possible tactics with Qa5, but that's not going to happen against decent opposition

Well, the Qa5+ tactics is exactly what's going to happen, and Black also threatens ...a6, ...b5 and ...c4 trapping the Bishop. It looks like White cannot avoid losing a piece, but he will only get a pawn and some light pressure in return.

[FEN "rnbqk2r/pp2bppp/5n2/1Bpp4/8/3P1N2/PPP1QPPP/RNB1K2R b KQkq - 3 7"]

1... Kf8 2. Ba4 {2. a4 doesn't help because of ...a6, trapping the bishop; 2. Nc3 fails to ...d4 and the bishop will again be unprotected} Qa5 3. Nc3 d4 4. O-O dxc3 5. Re1 Qd8 6. bxc3


Lc0 gets slower if weight file gets bigger

The bigger weights file corresponds to a larger Neural Network, which means more computation per node, but better evaluation per node.This is expected, and there is nothing that can make a bigger NN as fast as a smaller NN. The best solution is to use a small NN for blitz time control. I would personally recommend LD2 (available at Lc0.org/LD2)


You speak the language of my people.

There's nothing magical, unfortunately.  You must avoid 'target fixation'.  That is, even if you're close to delivering mate, you have to stop before every move, and look at every piece your opponent has. Every time.  And you must remember that your opponent is choosing moves for a reason. One of those reasons is to snap your pieces off the board.

So the other thing you can do is to be cognizant of basic tactics such as pins, forks, x-rays, etc.  You can work on these by running a tactics trainer.


Can't a pawn capture onto the last rank to promote?

Since the board is mirrored, the pawn is on b7 and the rook on a8. But b7xa8 promoting to a piece is a valid move.
I'm not sure which program/website this is, but it could be that a popup is asking to which piece White wants to promote, and something/your browser is blocking this popup, and your friend cannot complete the move.


Chess.com, along with FIDE, awards the full point to your opponent if you run out of time, unless your opponent has insufficient material: not enough resources to feasibly carry out a win. This effectually concedes victory to both players, which is sensible since on the one hand, your opponent rendered you incapable, but on the other, you held him off until he had no time to finish you off.

However, Chess.com's definition of "insufficient material" differs from FIDE's Laws. Chess.com simply looks at your material. If you have lone K, KN, KB, or KNN, you have insufficient material. So in your case, your opponent ran out of time, but since they determine that you could not have checkmated him anyway, Chess.com split the point.

Whereas FIDE calculates all possible futures; if one legal series of moves results in checkmate against the player whose flag fell, flag-fall is a loss for that player:

  6.9
  Except where one of Articles 5.1.a, 5.1.b, 5.2.a, 5.2.b, 5.2.c applies, if a player does not complete the prescribed number of moves in the allotted time, the game is lost by that player. However, the game is drawn if the position is such that the opponent cannot checkmate the player’s king by any possible series of legal moves.

Just for kicks, let's see one of these legal series of moves wherein you checkmate your opponent.

[FEN "5Q2/8/8/8/2k2P2/6K1/4n3/8 w - - 0 0"]
[startflipped "1"]

1. Kg4 Kd4 2. Kg5 Ke4 3. f5 Nf4 4. f6 Kf3 5. Kh6 Kg4 6. Kh7 Kh5 7. Kg8 Kg6 8. Qe8+ Kh6 9. Kf8 Kh7 10. f7 Ng6#

That's why FIDE would count flag-fall to be a win for you. Chess.com does not. To be fair, that or any line resulting in victory for you is so far-fetched that in this case, it's hard to complain that you could feasibly have won.*

Sources: FIDE Laws of Chess, Article 6.9; Chess.com forums - list of threads with "insufficient" in the title.

*There are a couple positions, however, in which King and Knight can force a checkmate vs. King and Pawn. For example, there would be ample cause of complaint if Black purposely runs out of time in the following position:

[FEN "8/8/8/8/N7/p7/k2K4/8 w - - 0 0"]

1. Kc2 Ka1 2. Nc5 Ka2 3. Nd3 Ka1 4. Nc1 a2 5. Nb3#


I can think of a couple counter arguments against what your friend says:

1) Sure in the Caro-Kann you can easily develop your Bishop outside the pawn chain, but there are several variations where the Bishop ends up being a target when developed to f5. The most prominent example is in the advance Caro-Kann:

[fen ""]
1. e4 c6 2. d4 d5 3. e5 Bf5 4. Nc3 e6 5. g4

The fact that the pawn is on c6 means the b8 knight is deprived of its best square to pressure the base of the pawn chain on d4. Essentially you are trading your traditional bad bishop for a bad knight. You can't have everything!
Because black played c6 first, a further c5 to pressure the center if not well timed is a loss of tempi compared to the french where you play c5 in one go. This means that in a lot of lines, black must do a lot of prep work before he can afford to play c5, meaning there is also less pressure against white's center. This allows white a lot more leeway as to how he wants to organize his forces. Compare this to the french advance where you quickly play moves like c5, Nc6, Qb6 to pressure the center. Those moves certainly aren't possible to play as quickly in the Caro-Kann. Furthermore, if black opens the center too quickly in the Caro-Kann, he may wish his bishop were back inside the pawn chain to guard against annoying checks on the a4-e8 diagonal!

Ultimately, a debate over whether or not the Caro-Kann is better than the French is fruitless. They are both good openings of equal strength, and your choice to play one over the other is a purely stylistic choice.


Can these chess terms be used interchangeably?

"positional advantage"  -- This could refer to a better pawn structure or deployment of forces; a knight outpost or the opponent has doubled pawns etc.
In battle it could be having the high-ground.

"initiative" and "attack" are used similarly, but "initiative" is who can make the next threat.  For example, in Tennis: you have the serve = initiative.  You make a good serve and are able to rush the net (keeping the initiative -- threat after threat) = attack.

"pressure" is making threats against weaknesses.  So, you might have a positional advantage, say your opponent has weak pawns, but if you don't attack them where is the pressure?

"play" and "counter play" refer to the ability to make threats.  If you are completely on the defensive then you have no play.

"active moves" are moves that seek to attack/counter-attack as opposed to passivity.

So now I hope you can understand this:
"I had a positional advantage, which I turned into an attack, but he sacrificed the exchange and got counter-play.  I defended and was able to consolidate my material advantage."


How to make a chess engine that can identify tactics in the position?

Yes, you can of course create a chess engine that does that. What you're saying is just a tiny part of engine search tree. You will need to read about more chess programming to get yourself started. Please come back when you have a concrete question.

Stockfish is free, why  not start from it?


Are there ever scenarios where more pawn islands are preferred?

Such scenarios arise occasionally in the late endgame.  For example, this position is a win for white (LiChess):

[fen "1k6/8/8/7p/P2P2pK/8/8/8 w - - 0 1"]

while a similar position (where white has fewer pawn islands) is a draw (LiChess):

[fen "1k6/8/8/7p/PP4pK/8/8/8 w - - 0 1"]

In the first case, if black's king captures a pawn, the other white pawn promotes (although white needs to play precisely).  In the second case, black's king can stop both from promoting because they're closer together, i.e., because of there being one pawn island.


Analyze, improvement - My game without blunders?

As noted in the comments, after 7.Qxb7??, the reply ...Bc6! simply traps the queen, leaving White completely busted. This may be the most obvious thing both players failed to notice in this game, and one of the few concrete ones I will bring up in this answer.

To me, it looks like this game is not an elite game, and it would be interesting to know your overall strength. I can assure you(without even analysing deeply), that black made more "mistakes" in this game than just missing 7...Bc6, but they may be more or less relevant depending on your level of self critisism, and ambition.

Let's take for example the position after 10.Qa6 by White: Did you consider playing ...Nb4, threatening both the queen on a6 AND a nice fork on c2? To me, not considering the move could be considered as a mistake, but at that point you already had quite a nice position, so most reasonable moves by black should be enough to win by then.

But there are other considerations to be made in the game. I think, that in this game, you did not develop your f8 bishop efficiently. This I view as a mistake, but it's not a tactical mistake, rather a positional one. But White never capitalised on this in any way, so you weren't punished for it. And this is the important point I wanted to make with this answer:

In this game, you outplayed your opponent, and the reason for it was that your opponent didn't play well enough to stop you from bullying his queen around the board. Therefore, your opponent will have a much easier time to learn from this game than you will. Your opponent got the "You play badly, and here's why"-treatment from you this game, but you didn't get the same treatment from anybody! Therefore you think you played great, no matter what the reality of your play is like.

This is the reason why it's easier to learn from your losses than from your victories in general. I would advise you to go through this game yourself with a bit more self-critisism, if you really want to take anything from it.


Some general advice about kings cut off on the 7th(or2nd) rank in rook endgames.
Involve your king or get your N to f3.
1.Kg1 Nf5!? {going after the f3 pawn.} 2.Rxc5 Nd4 (2...Kg6 also comes into consideration but
 is not tricky enough. although it is my personal fave) 3.Kf1! (3.Ne5?? Rxe5! -+) Rh2=

Involve a pawn!
1.Kg1 h5! {in order to get a pawn to h3 or f3 ASAP. Black will then threaten mate in two ways: ...Rg2# and ...h2#} 2.Rxc5 g4! -+

I have only used my head to give instructions. No computer, just to show what the general plans are. I'm IM but compared to a comp I'm nothing. So please forgive me if this is completely wrong. The general ideas are still valid though!