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Posted by ganstaman austinfilmfestival.org 5/04/2008 08:11:43 play online chess	Subject: Puzzle 283 Message: Ok, the puzzle on the homepage at the time of me writing this (search for puzzle number 283 here: gameknot.com ) White to move, mate in 4. I won't spoil the solution given, as it is brilliant seeming to me. But how can black spoil white's plan of Qh4-(h or e)7-b7#? I can see black delaying the journey by 1 move, so it would be mate in 4. What did I miss, if anything?
Posted by heinzkat austinfilmfestival.org 5/04/2008 08:21:53 play online chess	I think the answer is Message: 1. Qh4 Rh1!
Posted by sf115 austinfilmfestival.org 5/04/2008 08:35:09 play online chess	Message: If 1. Qh4 Rh1 white either: 2. Qxh1 a1=Q 3. Qh7 Qxa6+ 4. bxa6 b1=Q 5. Qb7++ which is a move slower than the actual solution. OR 2. continue with the original plan with 2. Qe7 Rh8+ 3. Nd8 Rh7 (3...Rxd8 also slows down whites mate) 4. Qb7+ Rxb7 5. axb7++ which is also in 5 moves. So there is only a mate in 5, which is slower than the actual solution
Posted by ganstaman austinfilmfestival.org 5/04/2008 09:50:31 play online chess	Message: Ah, that seems to do it. Thanks.
Posted by lighttotheright austinfilmfestival.org 5/05/2008 03:53:48 play online chess	Message: There is an alternate solution that is not accounted for by this puzzle. This kind of thing irritates me. It turns out that my first choice was in fact correct, but the puzzle said I made a mistake. Once you know the solution, it is easy to see that my alternate path works because mine is based on the same principles that are used in the given one. It's still mate in four, but why are alternate solutions unaccounted for? I thought that problem was fixed long ago.
Posted by heinzkat austinfilmfestival.org 5/05/2008 04:22:15 play online chess	That problem was fixed long ago Message: Lighttotheright, I think you're wrong here though - puzzle 283 has only one solution (for mate in four).
Posted by lighttotheright austinfilmfestival.org 5/05/2008 04:33:40 play online chess	Message: The alternate 1. Nd8 works and is confirmed. It is mate in four just like the given solution.
Posted by lighttotheright austinfilmfestival.org 5/05/2008 04:38:41 play online chess	Message: Heinzkat -- I'm not wrong. 1. Nd8 does work. The problem is that no computer can solve this particular problem from four moves out. The computer checking the solutions is wrong. Once you input the solution, the computer suddenly sees the solution at 2 or 3 moves out depending upon the program that you use. This particular puzzle is an anti-computer one.
Posted by heinzkat austinfilmfestival.org 5/05/2008 04:47:30 play online chess	Lighttotheright! Message: This is the interesting part of the puzzle, which is not covered in puzzle #283, since the puzzle application didn't support underpromotions of the opposite side back then. After 1. Nd8? [if I may boldly give it a ?] c2 2. Qc1 b1=B! Black is stalemated and there can be no mate in four. After 1. Nb4 however, 1. ... c2 2. Qc1 b1=B 3. Nd3! exd3 4. Qh1, it IS mate in four :-)
Posted by chessnovice austinfilmfestival.org 5/05/2008 04:48:12 play online chess	... Message: Sometimes puzzle makers don't have solutions entered entirely. Human error is prone to omissions. If you find an alternate solution, you're able to enter it. Nothing to necessarily get irritated about, I think.
Posted by heinzkat austinfilmfestival.org 5/05/2008 04:55:26 play online chess	Also... Message: Remember GameKnot does no checking of the puzzle at all - the puzzle application merely checks if all variations end in checkmate. If so, the puzzle is 'approved' 'correct' (twice '', ah well) an can be put up for others to solve. As you can see on the puzzle page, a lot of the puzzles still have some hiatuses then. If you think 1. Nd8 mates in four too, 'prove it'! You can do so by browsing to puzzle #283, hover over 'Options' in the right corner and click 'Alt. solution...'. This will give you the option to prove there is another way to play, that results in mate in at most the same number of moves as the original author. If all variations are correct, you can save the puzzle too, and the puzzle has been 'improved'.
Posted by lighttotheright austinfilmfestival.org 5/05/2008 04:58:36 play online chess	Message: 1. Nd8 c2 2. Qc1 b1=B 3. Nd5 Qb2 (or any move) 4. Nc7# It is forced checkmate. There is no stalemate with my solution. The alternate is confirmed, and not seen by computer at four moves out.
Posted by lighttotheright austinfilmfestival.org 5/05/2008 05:00:17 play online chess	Message: 1. Nd8 c2 2. Qc1 b1=B 3. Nd5 Bb2 (or any move) 4. Nc7# Sorry I made a slight error in copying the line. This is correct.
Posted by heinzkat austinfilmfestival.org 5/05/2008 05:01:19 play online chess	2. ... b1=B! Message: Not 2. ... b1=Q. Please re-evaluate your assessments. :-) (note that I hadn't noticed the b1=B solution either. A nice brilliancy by Ado Kraemer)
Posted by heinzkat austinfilmfestival.org 5/05/2008 05:02:30 play online chess	Lighttotheright Message: 3. ... Bb2 is not possible in the intended line! It's 2. ... b1=B, not 2. ... bxc1=B.
Posted by lighttotheright austinfilmfestival.org 5/05/2008 05:03:18 play online chess	Message: I did it again. 1. Nd8 c2 2. Qc1 b1=B 3. Ne6 Bb2 (or any move) 4. Nc7# Those knight moves can get confusing. I think this is correct now.
Posted by lighttotheright austinfilmfestival.org 5/05/2008 05:06:00 play online chess	Message: Heinskat look at the position. The key to the solutiion is the knight path. The Queen sac is to block any defence by black. The solution is very simple. 1. Nb4 and 1. Nd8 both work.
Posted by heinzkat austinfilmfestival.org 5/05/2008 05:06:23 play online chess	Note that in your line... Message: 3. ... Bb2 is illegal. In fact, after 3. Ne6, all Black's moves are illegal - it is stalemate!
Posted by heinzkat austinfilmfestival.org 5/05/2008 05:09:59 play online chess	OK... with a diagram then... Message: After 1. Nd8 c2 2. Qc1 b1=B 3. Ne6 It is Black to move. Do you see any legal ones? Interesting how Ado Kraemer can still keep us busy with his brilliant problems, 36 years after he died.
Posted by lighttotheright austinfilmfestival.org 5/05/2008 05:14:36 play online chess	Message: OK heinzkat. You threw me for a loop with b1. I was thinking about the c1 square. But even with b1=B, it is still checkmate in four. 1. Nd8 b1=b 2. Qxc3 and my solution still works.
Posted by heinzkat austinfilmfestival.org 5/05/2008 05:21:11 play online chess	Well... Message: 1. Nd8 c2 2. Qc1 b1=B is the line that makes mate in four impossible. 1. Nd8 b1=B like you give in this last post, perfectly mates in four - but there's a difference. Carefully check the notations right from the beginning of this thread, I think I haven't messed up any of them...
Posted by lighttotheright austinfilmfestival.org 5/05/2008 05:21:54 play online chess	Message: OK...It is still not stalemate. But it would be a mate in 5 instead. 1. Nd8 c2 2. Qc1 b1=B 3. Qxc2 and it is not stalemate. ...but it does take an extra turn to get the knight to c7.
Posted by lighttotheright austinfilmfestival.org 5/05/2008 05:24:17 play online chess	Message: Sorry for some of the copy mistakes. My copy function on my computer is not working. I have to reboot my whole computer to correct the problem.
Posted by heinzkat austinfilmfestival.org 5/05/2008 05:24:20 play online chess	Exactly... Message: And therefore, 1. Nd8 is an incorrect try. Mate in five is possible in many ways - there is only one correct starting move to mate in four.
Posted by lighttotheright austinfilmfestival.org 5/05/2008 05:58:50 play online chess	Message: Well, it looked correct to me at the time. And my computer was not cooperating with me either!
Posted by chessnovice austinfilmfestival.org 5/06/2008 13:55:37 play online chess	... Message: b1=B is pretty clever! Indeed, prolongs the Nd8 line by one move. I wouldn't worry about not considering that though, since I doubt that very many people really would.
Posted by bogg austinfilmfestival.org 5/06/2008 15:13:15 play online chess	In case anyone else has the ... Message: same problem that I had. The reason that 2. ... b1=B doesn't cook 1.Nb4 and does cook 1. Nd4 and 1. Nd8 is because after 1.Nd4 White has 3. Nd3 ed: 4. Qh1++. Took me a while to see the tree within the forest. CTC
Posted by heinzkat austinfilmfestival.org 5/07/2008 01:30:09 play online chess	chessnovice Message: Obviously the composer did consider it :) bogg: indeed, see my post above too, 5/05/2008 04:47:30
Posted by chessnovice austinfilmfestival.org 5/07/2008 01:44:28 play online chess	hienzkat Message: True. But if you can't trust the composer, who can you trust?
Posted by bogg austinfilmfestival.org 5/07/2008 06:35:06 play online chess	heinzkat Message: Missed that post. Would have saved me some time had I noticed it. CTC
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