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|Oct-09-08|| ||Marco65: 22.Ng3 might not be the best defence but is probably the one that most requires precision on Black's behalf to win:|
22...Rf4! (22...Bxd1 23.Bxb4 Bxb3 24.Qe6+ Qxe6 25.dxe6 Bxe6 26.Bxe7 Rf2 wins but less convincingly, and 22...Bf3 23.Qe6+ is similar)
23.Qg2 (to cover c2, otherwise 23...Qg6+ is deadly)
23...Bxd1 24.Bxb4 Qxd4! and White has to lose the queen to escape mate: 25.Kc1 Qa1+ 26.Kd2 Qxa2+ etc
|Oct-09-08|| ||kirchhoff: I guess I got it today. I chose Bxg4 with White responding with 22. Kc1 (Qxb4 loses to Q-g6+, K-a1 loses to B-f5 and there is no safe square for the White queen after N-c2+, and I didn't consider Bxb4 since that loses the queen.) Then 23. B-f5 Q-g2 24. N-a2+ K-d2, 25. Q-b4+ K-e3, 26. Qb3+ and white starts losing material. I enojyed this one.|
|Oct-09-08|| ||5hrsolver: 21...Bxg4 opens all lines of attack for black. Took me less than 5 hrs for this one. I wonder what friday might bring.|
|Oct-09-08|| ||chopin4525: <newzild: I missed this too. |
I saw the same variation as Dzechiel - 1...Nxd5, when 2.Qxd5 runs into 2...Be6 followed by 3...Bxb3.
Maybe "our" 1...Nxd5 move is okay? Any computer analysis would be more than welcome...>
Here is Rybka analysis
1: Tolush - N Kopilov, Leningrad 1954
click for larger view
Analysis by Rybka
23...Qc6 24.d5 Qd7 25.Bc3 Bxg4 26.Bxg7 Qf5+ 27.Ka1 Bxe2 28.Qxa3 Rf7 29.Bc3 Bxd1 30.Rxd1
(2.35) Depth: 21 00:14:57 105mN
|Oct-09-08|| ||chrisowen: Interesting game. Within twenty moves white has a tactically superior position and 20. Rc1 would've sealed it. Instead Ne2 allows 0-0 and black escapes.|
|Oct-09-08|| ||Patriot: I completely missed this. I tried to follow the forcing lines by looking at all checks, captures, and threats. But after 21...Bxg4 22.Qxg4 I couldn't see the follow-up 22...Qg6+ for whatever reason--the only candidate that makes Bxg4 worth considering.|
21...Nxa2 seems no good after the obvious 22.Kxa2 and 22...Qxb3+?? 23.Kxb3 and black has no follow-up.
21...Nxd5 22.Qxd5+ Be6 23.Qc5 is white saying "I'm up a piece so let's trade queens!"
21...Bf5 22.gxf5 and now what? So then I considered 21...h5 to decoy the pawn on g4, but the simple 22.h3 is good enough.
21...Rf4 22.Nxf4 seems to do nothing but lose the exchange and then some.
At this point I threw in the towel since I spent enough time on it.
What I find most interesting about these positions is that they have a "chain of events"--checks, captures, or threats on the next move that make a sacrifice, for example, worth looking at. So if you are considering a sacrifice and the chain is broken before gaining back material or checkmating, then the line is most likely bad.
|Oct-09-08|| ||johnlspouge: Thursday (Medium):
Tolush vs N Kopilov, 1954 (21…?)
Black to play and win.
Material: B for R+P. The White K has 2 legal moves, both dark squares on the back rank. The Black Pa3 take one dark square on the 2-nd rank from Kb1; Nb4, one light square. The Black Qb6 and Bd7 have pressure on Pd4. The Black Rf8 has an open file, although all its invasion points are guarded. The White Kb1 shares a file with the Black Qb6 and the White Qe4. Only the Black Bc8 requires activation.
Candidates (21…): Nxa2, Rf3, Bxg4
(A) 22…Bf5 pinning Qe4 to Kb1 or
(B) 22…Bf3 forking Qe4 and Rh1
White can accept the sacrifice but runs into a cousin of Philidor's Legacy:
(1) 22.Qxg4 Qg6+ 25.Ka1 [Kc1 Qc2#]
25…Nc2+ 26.Kb1 Nxe1+ 27.Ka1 [Kc1 Qc2#]
27…Nc2+ 28.Kb1 Ne3+ 27.Ka1 [Kc1 Qc2#]
Black has Q+B for R.
White can decline the sacrifice. To avoid the double threat, he must move his Qe4, but to avoid the variations above must neutralize the b1-h7 diagonal by blocking it:
(2) 22.Qe3 Rf3 23.Qd2 [Qxf3 loses] Bf5+ 24.Ka1 [Kc1 Qc7+]
24…Nc2+ 25.Kb1 Rxb3+ 26.axb3 [Kc1 Rb1#] Qxb3+ 27.Kc1 Qb2#
|Oct-09-08|| ||stoy: Kopilov also beat Botvinnik in a dutch: game 35 or 38. They are the same game. Why does he have so few games in the database? Thanks to anybody who can tell us.|
|Oct-09-08|| ||The Rocket: this was a bit difficult at first but when you see that theres a very good pawn at a3 and a knight at b4 suddenly I realised that If I can check the white king I win and by "sacking the bishop" the queen cant take it because of queen g6 + ! leading to king a1, Knight c2+!king b1 knight e3+ and the white queen is dead!.|
I actually thought that white would take the bishop after yesterday puzzles weak defence from the loser of the game but of course the response from white here also loses.
|Oct-09-08|| ||YouRang: Well, I solved this one in a rather unusual way. I spotted the lovely queen-pin ...Bf5 right away. I also noticed that it didn't work because of the pawn on g4.|
I saw no good way to make the queen-pin threat work except to take the pawn: 21...Bxg4!, which of course threatens 22...Bf5, winning the queen. So, I am forcing black's hand here, but does it do me any good if 22.Qxg4 ?
Without seeing the winning idea, I just started looking at moves that I could now make that I couldn't make while the white queen was on e4. That is, I just assumed that deflecting the queen was part of the plan.
Before long, I noticed that, yes, I now have 22...Qg6+, which threatens mate in a manner that white can do little about. Of course, 23.Kc1 Qc2# is out, but 23.Ka1 Nc2+ 24.Kb1 Ne3+ wins the queen.
Okay, I didn't look at many alternatives to 22.Qxg4, but I was satisfied that white couldn't take it, and I was pretty satisfied that white had to lose the queen (one way or another) to avoid mate.
|Oct-09-08|| ||The Rocket: This puzzle is a good lesson about tactical play, you search for a good attack.. and even though your opponent prevents it you calculate what happens if you remove the defender! even with a piece such as in this case.|
You have to think "outside the box" to become strong tactically sometimes concidering every possible move to eventually find the right one.
Though at medium level this puzzle required zero calulation but instead imagination.
|Oct-09-08|| ||cydmd: I think a have a shorter line for the main variation|
21... Bxg4 22.Qxg4 Qg6+ 23.Ka1 Nc2+ 24.Kb1 Nxd4+ 25.Ka1 Nc2dbl+ 26.Kb1 Nb4+ 27.Rd3 Qxd3+ 28.Rc1 Qc2#
I didn't check it. Anything wrong?
|Oct-09-08|| ||VooDooMoves: I too looked at 21...Nxd5 to clear the b-file and to bring the bishop in with tempo. Got excited when I saw 22. Qxd5+ Be6 23. Qe4 Bxb3 24. axb3 Qxb3+ and mate next move. Got bummed when I saw 23. Qc5 :(|
|Oct-09-08|| ||patzer2: For today's Thursday puzzle solution, Black's 21...Bxg4! offers White a poisoned piece (decoy/deflection) that he cannot accept, due to the threat of 22. Qxg4 Qg6+ with a mating attack. |
After 21...Bxg4! 22. Bxb5 Bf5 , Black's pin on the Queen wins decisive material.
|Oct-09-08|| ||zb2cr: Bah. The position was too complex for me. I came up with a long list of candidate moves, and churned through a lot of them over the course of about 20 minutes. I lost patience before I got to the evaluation of the actual game move.|
|Oct-09-08|| ||ruzon: <YouRang: Before <long>, I noticed that, yes, I now have 22...Qg6+, which threatens mate in a manner that white can do little about.>|
My <long> lasted until I played through the game. This is the first puzzle in a long while where I had no real idea what the plan was.
|Oct-09-08|| ||Woody Wood Pusher: 21..Bxg4 was the only move I considered.
Once you realize the white queen cannot move, the solution is quite straightforward.
I do not think white defended as well as he could (again!) and went down to easy.
e.g. 21..Bxg4 22.Bxb4, Bf5 23. Qxf5,Rxf5
and now 24.Bc5,Qg6 25.Kc1,Rf2 26.Rd2,Qe4 etc is not pretty but black still has to work a little
24.Bxa3 is just throwing in the towel.
|Oct-09-08|| ||Woody Wood Pusher: Those people who considered 21...Nxd5?? need to watch their caffeine intake! |
22.Qxd5, Be6 23. Qa5,Qxa5 24. Bxa5,Bxg4 and white has nothing but a lost position IMO, but yea if somebody could check these lines with a computer that would be much appreciated.
|Oct-09-08|| ||Woody Wood Pusher: OK just saw your post <chopin> nice one.|
|Oct-09-08|| ||whiteshark: Today completely clueless. (oh, it's Thursday)|
|Oct-09-08|| ||DarthStapler: I got the first move|
|Oct-09-08|| ||zenpharaohs: agb2002: "don't analyse unnecessary tactics"
How can you tell if they are unnecessary until you analyze them?
|Oct-10-08|| ||kevin86: I missed this one. I guess white's defense move only delayed the pin one move. I guess there wasn't a place for the queen to move BEFORE the pin.|
|Oct-10-08|| ||Kasputin: A little late looking at this one - anyway...
White is up the exchange plus a pawn. White's king is hemmed in quite a bit and black's queen and bishops look ready to attack the king as soon as more lines are opened.
One candidate that jumps out is 21 ...Bxg4. The bishop can't really be taken by the white queen because this allow 22 ...Qg6+ and if 23. Ka1 then 23 ...Nc2+ with a discovered check and attack on the white queen after 24 ...Ne3+. (23. Kc1 of course allows ...Qc2#). And who knows, there may be worse for white in this line, but seeing this much is enough to see that white can't take the b4 bishop.
So if the g4 black bishop is immune from capture, what can white do instead? Again the candidate move is:
This move sets up multiple threats. For example, 22 ...Bxe2 looks dangerous, although white may be able to come out okay. But black also threatens 22 ...Bf3, which looks nasty as well. So for instance 22. Rd2 (in order to cover the e2 square with the rook), then black can play ...Bf3 in order to fork the queen and rook.
But even better than that, black can simply play 22 ...Bf5 and black skewers the queen and king. The threat of this move also wrecks, for example, the try 22. Bxb4, which otherwise might be white's best attempt to get out of the mess.
So after 21 ...Bxg4, white either has to move the queen somewhere (but can this prevent the devastating ...Qg6+ as mentioned above?) or has to move the king to a1 or perhaps c1 (in order to break the f5 bishop skewer).
Well clearly if the queen moves, it cannot remain on the b1-h7 diagonal because of ...Bf5. White can try 22. Qe3, but this won't work. Again black has 22 ...Qg6+. Like the line above that prevents the capture of the g4 bishop by the white queen, white is unable to play 23. Ka1 because of ...Nc2+ (the knight gets to eat both the queen and the d1 rook in this case because of the discovered check). But white cannot play 23. Rd3 because black simply wins that piece with the knight or the queen (remember the g4 bishop is still there in this variation and so black is up a piece). As far as I can see, I cannot see a queen move that prevents the damage done either by 22 ...Qg6+ or 22 ...Bf5
Moving the king with 22. Ka1 however still allows 22 ...Bf5. Now white has to move the queen. It cannot go to e3 because of the knight fork on c2. If 23. Qf3 or even 23. Qg2 then ...Nc2+ and then after 24 ...Nxd1+ the queen still gets captured by the knight.
All of this seems only to leave 22. Kc1. This can't be good for white either. I see 22 ...Nxa2+ and then 23. Kd2. Kd2 is basically forced since moving the king back to b1 or to c2 allows the ...Bf5 skewer once again. In any case, with the white king on d2, black could play 23 ...Bf3 forking the queen and rook. Perhaps there is something even better than this, but even if this is the best line, then black should win without difficulty.
Okay, only a day late. Time to check.
|Oct-10-08|| ||Kasputin: Well I saw quite a lot of this but certainly not all of it. I guess the main thing is that I should have looked more closely at 22. Bxb4 instead of just assuming that the queen/king skewer would automatically be best. It is best as the actual game continuation shows, but it isn't automatic either. Tough puzzle. No lines need to be examined in any great depth in order to see the win, but there are lots of possible responses after 21 ...Bxg4 and making sure that each of them is examined sufficiently is not easy - at least to a player like me.|
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