Hot answers tagged

80

To get out of check, the king needs to move to a square that isn't attacked by any opposing pieces, or you need to capture/block attacking pieces such that the king is no longer under attack on its current square. Since the queen is attacking the king and both of the unblocked squares it can move to, white needs to capture the queen to get out of check here. ...


35

Really interesting question. I think the following shows that such a situation is sort of possible, depending on how you define the pin. [StartFlipped "0"] [FEN "7k/4p3/8/2KP3r/8/8/8/8 b - - 0 1"] 1... e5 2. dxe6?! {Illegal move!} Now, 2. dxe6 is illegal. The check would go from being stopped by both pawns, to being stopped by neither.


26

Rook at d2 is pinned by the bishop at g5 and hence the rook can not capture the black queen at c2 checkmating the white king at c1.


26

Since you are a beginner in chess first you need to understand the term pin in chess. In chess, a pin is a situation brought on by an attacking piece in which a defending piece cannot move without exposing a more valuable defending piece on its other side to capture by the attacking piece. Now, coming to your answer: Rook cannot capture the queen at f7 as ...


21

No. The touch-move rule can't force you to make an illegal move, and it is not legal to put yourself in check. Here's what the FIDE laws of chess say: 4.5 If none of the pieces touched in accordance with Article 4.3 or Article 4.4 can be moved or captured, the player may make any legal move


14

Your description of the computer's suggestions doesn't quite match the position, but if you mean the computer suggests Nxe5, that is correct, as Bxd1 leads to a variation of Legal's Mate. Nxe5 Bxd1 Bxf7+ Ke7 Nd5# If, instead, Nxe5 dxe5 Qxg4 and white has won a pawn, and has a big lead in development.


12

You're referring to ...Bc8-g4 as a threat. The only threat it makes is ...Bg4xf3, losing time and the bishop pair. While White has d4 under wraps with a pawn at c3, theere's no ...Nc6-d4 coming to pressure the pinned knight. The f6-knight has to move to a lesser square to prepare ...Qd8-f6, which is nothing because Nb1-d2 is right at hand to prevent a ...


12

The original goal of chess was to capture the opponent’s king. The idea of “checkmate” follows this: you may as well call the game won/lost once capture next turn is inevitable. So you’re checkmated if whatever you do, your king would get captured next turn — i.e. if every move you can make would leave your king still in check. In your example: There are ...


11

To answer the subquestion: "Does anyone know if this is some kind of known chess variant?" Yes, it is a known chess variant. It goes under several names including PMDNC (Pinned Men Do Not Check), Pin chess, Superpin, or Stevens Principle. Its written history dates back at least to a publication by SJ Stevens in Westminster Papers in 1875.


10

To me one move was clear - Nxd5 But after 1...cxd5 2.Rc7, although the knight is pinned for a move, Black can easily unpin it by moving the queen to d6, d8, e6, or e8. In fact, the knight is not even fully pinned - Black could move it to c5 and force a queen trade. You've sacrificed the knight for a pawn, and get no lasting pin. Why 1. ......


9

Part of the problem with Bc5 is that they can respond with Na4, which threatens the bishop and grabs the tempo. Be7 isn't great because its range is inhibited by the knight and it impedes the kingside rook's power on the e file after you castle. Bd6 is nice because it is protected by the pawns, the bishop can be retreated to b8 or c7 while still controlling ...


8

I realize that it's hard to give general guidelines here, since every chess position has unique considerations. Still, any rules of thumb would be appreciated. I would rather be right 80% of the time than fly blind and "flip a coin" on these decisions every game. If he ignores your pin by castling / moving queen / interposing the bishop, you have 2 options :...


7

Let's stick to one color, white here, and everything we'll say will generally hold true for black as well. Rule of thumb: On the one hand, you generally don't want to move your king-side pawns (such as h3) when you've castled short, unless you have to, and we will expand on what "have to" entails here. The immediate exception to that is when you decide to ...


7

One of the key principles of opening play is that control of the center is vitally important. If one of the players has complete control of the center then they can much more easily launch an attack and it is much more difficult for the other player to defend. A white knight on c3 supports/attacks e4 and d5. A white knight on f3 supports/attacks e5 and d4. ...


7

No, that's not a checkmate. The white bishop is currently pinned (in absolute pin because it protects the king from check by Black's rook), so there's no legal move can be made by that bishop. In short, this situation has no consequences, and you still can touch the king to continue play since touch-move rule doesn't apply for pieces in absolute pin. Note ...


7

it still seems to me that White wins more material playing Qb1 instead of what appeared to be the solution No, if you compare the two final positions the only difference is that in the Nc4 line white has an extra knight and black has an extra bishop, so no difference if you are counting points. Why did White play Nc4, not Qb1? What am I missing? Good ...


7

White can't move their rook from d2 as your bishop at g5 will capture the white's king.


6

No, absolutely not. You are putting your king in check first from the Qd5. If you think about this way: Who could take the other king first since that really is what checkmate is? In this case, Kxg2 Qxg2 captured the white king first, and only after would Bxg8 take the black king...White lost the king first. Your thought also does not hold up to logic: ...


6

This task is nontrivial and cannot be obtained easily or setwise from the available bitboards. The following solution is an example for how such a task might be done for a generic slider - only obvious substitutions are necessary to convert this code to be usable for bishops, rooks and queens. First, identify the set of possible pinning pieces by ...


6

Bonus question : 4 pins stalemate without promoted piece. Here is a maximal solution with all 32 units : White's Rc2, Bd5, Nf2 and Ng6 are pinned. The king has no move and all the other white pieces are stuck. Removing any black piece, or moving the black King away, would break the stalemate. Removing the bPg4 would be particularly unfortunate because White,...


6

Think of it this way: Check mate is where nothing the opponent can do will save them from having you take their king on the next turn, so even if by putting their king in checkmate, you expose your own king, they can take your king before you can take theirs. There is NO circumstance in which your actions put your own king into check without an opponent ...


6

On a related note, enjoy a chess problem that demonstrates the weird mechanism of the pawn being pinned by the taken pawn. I pulled this from Yet Another Chess Problem Database. [Title "Erich Anselm Brunner, Deutsches Wochenschach 12/1908, Selfmate In 3"] [FEN "8/8/5Q2/2p3Pk/5R1P/5r2/1PPKB1P1/2NRB3 w - - 0 1"] 1. Ra4! c4 2. Qf7+ Kg4 3. ...


6

Black cannot exploit the pin with ...Nd4: not at once because the Nc6 itself is pinned, not later because c2-c3 is on your plan anyway. This means that you should not panic and can concentrate on developing before taking measures about the Bg4. You should not be afraid of a ...Qf6 either. After the later sequence ...Bxf3, Qxf3, Qxf3, gxf3, your king is ...


6

Adding to Philip's answer, I more remember it from the Scandinavian, because there the bQ gets out early anyway and it takes much less patzer moves to irreversibly trap it this way. Example: [FEN "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"] 1.e4 d5 2.exd5 Qxd5 3.Nc3 Qe5+ {or Qe6+, still 70 games up to here on Lichess} 4.Be2 Qf6? 5....


5

NEVER say never. Rules of thumb are just that. White very commonly plays h3 at an early stage in many variations of the Ruy Lopez, even before Black has committed his K. What often makes this safe is that Black may have already disarranged his own Q-side pawns by ..a6 and ..b5, so he is unlikely to castle over there. I remember learning this rule of thumb ...


5

Regarding the question - how to deal with very hard tactics? I'd suggest moving to an easier tactics book, where everything will be clear for you. After you will finish that book, move to a more advance book, and you'll find that your tactics abilities are much better. Below you can find a couple of possible continues after Rxc6 which shows why black ...


5

The rules are clear. A move that puts your king in check is an illegal move (I'll leave it to you to find the reference; you might find the other rules helpful to review once you get there). You cannot checkmate your opponent's king (or accomplish anything else) with an illegal move. Once you make an illegal move on the board, the following things happen: ...


5

A: Let's use bishop for our example. xrayBishopAttacks works if we have the following position: but it doesn't work if you have this: The f3 knight is not pinned because there is something else behind it. obstructed takes this into consideration. B: Once you get the pinned pieces, you can just do XAND to check if the piece you want to move is pinned. If ...


5

Bd6 is the most active square. No, there's not an immediate threat but it does attack h2 which could turn into something later. Be7 is too passive. It's not smart to "protect against pins" that haven't even happened yet. There's lots of unpin combinations that actually lead to the pinning side being worse. Also, white can't really capitalize on a ...


5

Bd6 has two big advantages that haven't been mentioned. The first is that it protects the b8 square for your rook. Your rook naturally belongs on the half-open file, and White really wants to play Bf4 to keep you from doing that. (You can put your bishop on d6 later if that happens, but you've wasted a tempo and exchanging bishops makes it easier for the ...


Only top voted, non community-wiki answers of a minimum length are eligible