Today’s Chess Problem 10/05/11

 

Hint: watch that d2 square…

1. This was tougher, I will again hold off on my answer but will give a second hint.  Black’s first move will be with a Bishop.

   Posted by Wes       10/05/2011  at  01:20 PM  



2. I think Wes has it.

   I mentioned we’re just going through the first part of the book. Weak back ranks. There are 59 problems in that section. I’ve only posted eleven. The next section features pins as the winning tactic. 169 problems in the ‘pins’ section. We can keep going for years.

   Wes, would you agree that your bishop move may involve a pin? A third hint?

   [Wink, wink. Nudge, nudge. Remind me to quit with the Monty Python references.]

   Posted by Christopher       10/05/2011  at  02:04 PM  



3. I think there just might be a pin involved.  I was going to say as much when I gave my hint but that would have telegraphed which Bishop had to move and exactly where.  I also did not want to give away that much information too early and stop others from saying anything.

   The problem with problems is that if you know there is a solution you are more apt to take the time to find it than over the board.

   I probably should wait a full day after you post one of these because before I chime in.

   Posted by Wes       10/05/2011  at  02:35 PM  



4. My first thought was that black should move the queen to a4, to make an attack in the lower left corner of the board. If white responds by moving the queen to b2 to counter the threat, then black can quickly win by knight takes bishop (c4-d3) for a check. With the queen out of the way white can only retreat the king to a1. Black then brings down the rook, c8 - c1, for the mate. But if white responds to the black queen at a4 by bringing up a pawn, b2 - b3, then that plan soon falls apart; 2 moves later getting the black queen to b2 doesn’t result in a mate. So that approach won’t win.

   Going for a “pin” with the bishop could result in a win, after a lot of fast bloodshed. Black moves his bishop e6-f5 to threaten white’s queen. White takes out the bishop with his knight, g3-f5. Black takes the knight with his queen, d7-f5, again putting the threat on the white queen. Or is it just suicide? White queen takes black queen, d3 - f5.

   Black responds with his knight, taking white’s bishop and putting the king in check, c4 - d2. White can only retreat the king, b1 - a1. Black brings the rook all the way down the board, c8 - c1, and it looks like mate. White has no choice but to move the queen to defend the king, f5 - b1, at which point black will take her with impunity: rook takes queen, c1 - b1, for the mate; the rook is guarded by the knight at d2 so the white king can’t hit him.

   This solution works, and it may be “best” for being the least number of moves, but I don’t like it. I don’t think it’s deterministic, and that’s the whole point of these things, isn’t it? Is it even bulletproof? Perhaps not. When black queen takes out white knight at f5, why not have white advance a rook, f1 - f3, for a counter threat? Sure, white can still loose his queen, but black will then loose his as well. I don’t see anything quick at that point, since both sides have lost half their strong pieces (white’s next move would be to pop black’s other bishop with his other rook, e1 - e7).

   PS - just what defines a “weak back rank”? Two rooks and a knight in place, some pawns in the way, and a bishop or a knight just one move out make white’s back rank look pretty sturdy to me.

   Posted by Drew458       10/06/2011  at  01:30 PM  



5. Well done Drew. 1… Bf5! and after the bloodshed you mentioned, White is mated.

   A weak back rank? Some of this comes with experience. In this case, sure White has two rooks and a knight on the back rank, but it’s the knight that is the problem. Both rooks are on the wrong side. They are cut off from protecting the king by their own knight. If White’s knight wasn’t there, there’s no mate with Black’s rook and knight. As for the pawns, well, they are blocking possible escape routes for White’s king. The king has no ‘luft’. (For an explanation of luft, see the Wikipedia entry ‘luft’.)

   Thanks for holding off Wes. Gave Drew a chance to get it right.

   Posted by Christopher       10/06/2011  at  05:29 PM  



6. Drew, your suggestion about moving white’s Rook f1-f3 will fail to black playing NxB for the check.  White’s Q cannot take back so it’s King to a1 and the black Rook at C8 goes to C1 and it ends like you called it the first time.  Pretty deterministic but complicated.

   Posted by Wes       10/06/2011  at  06:36 PM  



7. Thanks for stepping in there Wes. I completely missed that Drew said that. I was just jazzed that Drew got the solution. I was also trying to define a ‘weak back rank’.

   Drew, I finally thought of a definition for a ‘weak back rank’. Stuff that ‘experience’ lame excuse I posted previously. A ‘weak back rank’ is one in which your king is in imminent threat of being mated on the back rank. A weak back rank is something you wish on your opponent.

   But, as your question points out, the trick is to recognize when, and who, has the problem. If you have it, fix it. If he has it, launch your attack before he fixes it.

   Posted by Christopher       10/06/2011  at  06:48 PM  

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