Is it rude to ask my opponent to resign an online game when they have
a lost endgame?
Yes, it is rude, although you are in good company. In one Olympiad Victor Korchnoi is alleged to have asked his opponent - "Do you speak English?" When they said "Yes" he replied "Then please resign". I may be misquoting. He may not have said "please" :-)
If you promote to a queen with 1. b8Q, black has:
1...Re2+ 2. Kd1 Rb2
attacking the queen and hinting at mate with Rb1++. If white takes the rook 3. Qxb2 it is stalemate.
Because of the mate threat white does not have any other good square for the queen either (no good check and no square that would defend b1).
If you promote to a rook, black does ...
Brian Towers answered the question, but to help you understand why people don't resign, I recommend you watch this lecture by GM Finegold Blunders, with GM Ben Finegold. The gist of it is:
Never resign, and look for resources no matter how bad your position
is. And when you are winning, don't let your guard down.
White to move:
[FEN "8/q1P1k3/8/8/8/8/6PP/7K w - - 0 1"]
Since my example is rather contrived and artificial, I'll also say that the so-called Lasker trap in the Albin Countergambit gives a more realistic setting, and one where a knight promotion is the best option as early as move 7:
1.d4 d5 2.c4 e5 3.dxe5 d4 4.e3 $2 Bb4+ 5.Bd2 dxe3! 6.Bxb4 $4 ...
In the specific position that you mention, the answer is a resounding no. The king and the knight will defend each other, and white will not be able to force mate.
However, the knight is a clumsy piece. If the knight is not positioned perfectly, then the rook will frequently be able to drive the knight to a bad square and deprive it of moves. Eventually, ...
I believe your question essentially boils down to the topic of whether it is possible to completely "solve" chess. Wikipedia has an excellent article on the topic which should give you a good overview.
To summarise, the number of possible game variations in chess is estimated to be 10^120. This is a staggeringly huge number, for comparison, consider that ...
It's always rude to ask your opponent to resign. They should resign of their own accord once they're convinced that you're overwhelmingly likely to win the game. In my case, that always meant you'd have to convince me that you knew how to play the endgame in question and that both of us knew how you would win it.
If your opponent hasn't resigned yet, it ...
I know you're a FIDE Master :), so I suppose you're more interested in this question from a teaching perspective.
The simplest way to understand a checkmate with King and Rook vs King is the idea of the rectangle of the opposing king. Consider this position-
Here, the Black King is restricted by the White Rook in this giant rectangular area of the ...
I will preface this by saying that I'm a 2150 USCF player who has had the same issues that you are struggling with in the past. What I'm about to tell you comes straight from my own experiences playing chess all these years.
Don't study or memorize any theory straight up. I find it difficult to retain information like that and the potential for it to be ...
This is not a blunder, expected behaviour from the engine. Everything worked as intended. Try to copy the FEN string out, and you'll know.
Although the position looked winning, White didn't have enough moves to force checkmate before the 50 moves rule. Stockfish, knowing the position was a dead draw immediately asked for simplification.
The position you ...
Shirov resigned: the thinking was that despite both sides left with pawns and a knight, the advantage went to Black.
Black has an extra pawn and Black's pawn chain is mutually supporting. White is down a pawn and they are split. White's king is buried too deeply in the corner to either prevent a black pawn advance to promotion or to save White's pawns.
According to the Lomonosov tablebases, it's mate in 40 for black. While the queen can't force mate by herself, she can force a zugzwang. In this case, when the bishop is forced to move to e8. Then, it's a matter of giving checks until the queen forks the king and bishop.
One of the longest variations given is as follows:
[FEN "7k/5BpP/3K2P1/8/8/8/8/4q3 w -...
Actually, the bishop and knight mate is not as slippery as it appears. I have checked this on a tablebase program I wrote. On a 10x10 board, the side with the bishop and knight (say white) can force mate in at most 47 moves. White can even force mate on a 16x16 board, in at most 93 moves. I believe mate can be forced on an arbitrarily large even size ...
It's probably a trick problem with a promotion to a black knight.
Such promotions to the wrong colour are not allowed, and never were. In the official rules it is now specifically pointed out that the new piece has to have the same colour as the promoted pawn.
FIDE's laws of chess, Article 3.7 e:
When a pawn reaches the rank furthest from its starting ...
The weaker side needs to keep Knight close to his King in order to achieve draw.
There are some special cases where the stronger side wins even in those situations, like when Knight is cornered or pinned in such a way that puts weaker side in zugzwang.
If the Knight is far away from the King then the result of the game depends whether or not the defending ...
Seven man end game table bases are already available online:
By the end of 2013 they should be available off line as well. The size is 140 000 gigabytes so there is an obvious problem with copying them. They did not compute 6 white pieces versus 1 king since they decided it was pointless.
Interesting fact- the longest forced ...
I always like to explain this in a visual way.
Basic Idea: Keep the bishops together. They form a large net (restricted area) from which the opponent king cannot escape.
Step 1: Push Opponent's King To Edge Rank or File
Keeping the bishops together and using the king for support, make the restricted area smaller to push the opponent's king back to an ...
There is a very easy way to detect whether King and Pawn endgames are drawn or not.
This method I use is a very easy to understand one from Karsten Mueller and Frank Lamprecht's excellent book Secrets of Pawn Endings
It concerns key squares and opposition
The rule states that if pawn has not reached or crossed the central line (5th rank for White and 4th ...
Honestly it's rude to ask your opponent to resign in any position. The one exception may be them deliberately letting their clock run to 0 in a completely lost position, but in this case they're being deliberately malicious and you can't really hope to reason with them.
Even though you're absolutely justified in thinking your opponent should resign, that ...
During round 9 of the Istanbul 2012 Chess Olympiads, at the Nakamura-Kramnik table of the USA vs Russia match, we've witnessed another one of those promotions to knight at move 62 by white.
The relevant position (white to play):
[fen "8/2P1k3/8/8/5p2/5KbB/3pp3/3N4 w - - 1 62"]
1. c8=N+ (1. Kxe2? f3+ 2. Kxf3 Bxc7)
We can see here that if
There are several key positions from which it is easy to memorize the win. The basic idea is to drive the opposing king to the edge of the board, and then to the corner, where you can force the rook to separate from the king.
[White "King and Queen"]
[Black "King and Rook"]
Is it really possible to checkmate with two knights and king against a
Theoretically, the checkmate is possible, but you can not do it in practice unless the weaker side allows you to. This is related to a drawback in the way knight moves.
There is a mating position with this but no extra tempo to do it in
What are the ...
There isn't a clear-cut definition of endgame, or a set of criteria where you could draw a line and say "after this move, we have reached the endgame."
Quoting Glenn Flear in his excellent book Practical Endgame Play - Beyond the Basics:
The word 'endgame' is widely used and generally implies the final phase of the game (however long!), assuming that ...
Examples and instructions are taken from the book:
Y.Averbakh - Comprehensive Chess Endings Volume 3.
In many cases I felt no need to "reinvent the wheel" so I quoted the above authors. Those parts will be marked with apostrophes "", like this: "This is a quoted text".
Without further delay let us tackle this endgame:
"In endings of ...