72
votes
Accepted
Can you solve this unique chess problem of white's two queens vs black's six rooks?
It's checkmate in 20 moves. White's queens circle around the board giving checks, and Black interposes horizontally/vertically moving pieces. Black only has one choice because the other piece is ...
- 24.8k
60
votes
Stalemate situation with all pieces on the board
Here is an example of a 12-move game after which White (to move) is stalemated. All 32 units (pieces and pawns) are still on the board. The original version of this concept game was created by Charles ...
- 6,265
56
votes
How can I prevent checkmate in this position?
Initial Analysis
White is clearly in a dire situation, since Black is threatening mate in one on either h7 or h8 if White doesn't do anything. But the White king can't move nor can White get rid of ...
- 17.1k
54
votes
Can all 64 squares be attacked or defended by the eight pieces?
If the two bishops travel on the same color squares, then all 64 squares can be covered by the eight pieces. However, if the bishops must travel on opposite colors, then the maximum number of squares ...
- 616
53
votes
Accepted
How fast can checkmate occur by just moving the king?
Here is a starter solution in 7 moves.
Can we do better?
[FEN ""]
1.g3 e5 2.Bh3 Ke7 3.Bxd7 Kxd7 4.Kf1 Ke7 5. Kg2 Ke6 6.Kh3 Kf6+ 7.Kh4 Kg6#
If this is best, interestingly, the play is ...
- 15.8k
52
votes
Accepted
How is this position possible in a normal game of chess?
Double check is only possible by using discovered check. So either the rook check or the bishop check was discovered by moving something in between on the previous move.
I don't see how that's ...
- 27.8k
49
votes
Accepted
47
votes
How fast can checkmate occur by just moving the king?
It's impossible to checkmate faster than 7 turns (handicap on black) or 8 turns (handicap on white).
Proof by elimination
I'm going to argue from the perspective that white is helping and black is ...
- 571
46
votes
Why underpromote in this KNNP-KR endgame?
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 ...
- 20.7k
46
votes
Accepted
When was it possible for a player's king to be attacked by 3 of the opponent's pieces?
In my thread on the English Chess Forum, which seemed to make the world go crazy on the subject, I gave all the major and minor events in the history of the “legal” triple check that my extensive ...
- 17.1k
42
votes
Endgame problem: How to avoid stalemate and win?
It's quite a fun problem to think about, before getting to the
calculation of long variations, try to first spot the key idea needed to crack the problem.
Here are the first observations that come to ...
- 12k
40
votes
Accepted
Is the position in this trick question reachable?
Even though the board is upside down, the position is still easily legal.
[FEN ""]
[startply "86"]
[StartFlipped "1"]
1. a4 h5 2. g4 h4 3. Bg2 Rh5 4. gxh5 h3 5. h6 e5 6. ...
- 17.1k
39
votes
Please help solve this endgame problem posed by a friend
White is one tempo short of catching the pawn - if White could make two moves immediately it would be a draw as white would just take the black pawn. But they can't, so white has to find a threat ...
- 4,357
35
votes
White to play and checkmate in two moves
Use the fact that the rook is pinned, and that the king has few squares left;
I'm thinking that 1.Rd8 Kd3 (only possible move) 2.Nc5# should be the solution.
[White "NN"]
[Black "NN"]
[FEN "7R/1B1N4/...
- 7,988
33
votes
Longest sequence of mutually forced moves
Assuming you allow promoted material (since you didn't say anything :-),
this (on Page 13 of the PDF) is the (unfortunately, extremely unknown) finite record since ages. It shows the record for the ...
- 15.5k
33
votes
Accepted
Is there a position with the stupidest possible move?
Every single legal move from White checkmates—except the extremely stupid Bd7. There are 12 (discovered) checkmates with the rook on g2 alone. After the stupid move, Black is forced to give checkmate ...
- 6,010
30
votes
Accepted
What is the solution to this mate in 2 puzzle?
It is a nice little puzzle:
3k4/3P4/3Q4/8/8/8/8/4K3 w - - 3 13
1. Qd5 Kc7/Ke7 2. d8=Q# 1-0
- 24.8k
29
votes
What moves solve this mate in 2?
White to play checkmates in 2 with 1 d4+! exd3 e.p. 2 Qbf4#.
Black to play cannot checkmate in 2 but should win after Bxf7.
7r/1p3Q1p/2q5/3bk3/1Q2p3/2P5/r2P2PP/2KR4 w - - 0 1
1. d4+! exd3 2. Qbf4
- 6,524
28
votes
Is there any position where not promoting (illegally) would be the best move?
Here is an example:
[fen "8/4P3/8/4p1p1/2p3Pp/p4p1K/k1p2P1P/8 w - - 0 1"]
1. e8 leads to stalemate next move, while all legal promotions lose to 1... c1=Q followed by 2... Qf1#.
- 9,006
28
votes
What is the highest number of different mates in 1 you can have in one (legal) position?
[FEN "1B1Q1Q2/2R5/pQ4QN/RB2k3/1Q5Q/N4Q2/K2Q4/6Q1 w - - 0 1 "]
105 mates — Nenad Petrovic, Sahovski Vjesnika 1947 (Chess Problem Database)
In this position any check is mate. There are 3 knight mates ...
- 3,762
26
votes
Accepted
Can White avoid a loss in this endgame study by Lazar?
The first half of white's move is forced - d8. Then white has a choice of knight, bishop, rook or queen. Black has two threats which white must parry to get a draw. The first is to play Bf4 and then ...
- 94.5k
26
votes
Basic "mate in one move" puzzle - what am I missing?
You are absolutely right! The black king can move to d8 and e7 and then there's no follow up mate. Most probably there's a white queen/bishop on h4 to prevent the black king from escaping (which is ...
- 1,485
25
votes
Accepted
What is the least number of knights needed to cover the entire board?
Depending on whether occupied squares need to be covered as well, the number is:
[Title " 12 knights, Without Covering Occupied Squares"]
[FEN "8/5N2/1NN1NN2/2N5/5N2/2NN1NN1/2N5/8 w - - 0 1"]
[Title ...
- 20.7k
25
votes
Accepted
Can you solve this queen + 3 pawns vs bishop + 3 pawns chess problem?
If White can get the Black king to the first rank, then it will not be fast enough to catch the g-pawn from promoting. White starts by playing 1. Qg5, and after 1...Kh7 2. Qf6 Kg8 3. Qh6, the White ...
- 863
24
votes
Accepted
Is there any position where not promoting (illegally) would be the best move?
The Matt Bengtson problem Prof. Elkies mentions is:
[Title "Matt Bengtson, Chess Braintwisters (Burt Hochberg), no. 103. White to move & draw."]
[FEN "4kn2/3p1pPp/4pPpK/6P1/8/2p5/1b6/8 w - - 0 1"]...
- 6,265
24
votes
Accepted
Can you solve this chess problem of a lone knight against numerous opposing pieces?
OK
The check must come from the knight (D'uh!)
The black king must be on c5 for the mate
The white king must be used to cover any empty squares to the right of the black king - thus the white king ...
- 4,357
23
votes
Accepted
Is the "Pawn Box" possible in standard chess?
As @BrianTowers showed, it can be done. Here’s a shorter proof game for the fun of it.
[FEN ""]
1. h4 g5 2. hxg5 f5 3. g4 Nf6 4. gxf6 d6 5. gxf5 Be6 6. f4 Bb3 7. axb3 c5 8. e4 c4 9. bxc4 d5 10. cxd5 ...
- 17.1k
23
votes
Is there a double-forced mate position?
Indeed, there are many possible positions in which all mates are forced on the first ply. Since you ask not for that, I shall provide examples with more than one move by both sides.
Here is the known, ...
- 17.1k
22
votes
What is the shortest number of moves from the starting position required for Black to mate White with a pawn?
4 moves, as far as I can tell.
[FEN ""]
1. e3 e5 2. Ke2 Qh4 3. Kf3 d6 4. Qe2 e4#
Another one:
[FEN ""]
1. d3 d5 2. Kd2 e5 3. Kc3 Be6 4. Qd2 d4#
And one more:
[FEN ""]
1. e3 e5 2. Ke2 d5 3. Kd3 ...
- 3,806
Only top scored, non community-wiki answers of a minimum length are eligible