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| Aug-12-11 | | agb2002: White has a bishop and a knight for the bishop pair. Black threatens 25... bxa3.
The black castle looks weak and poorly defended. Hence, open it with 25.Rxh6: A) 25... Bxh6 26.Qg6+
A.1) 26... Kf8 27.Ne6+ Bxe6 28.dxe6 and mate in two.
A.2) 26... Kh8 27.Qxh6+ Kg8 28.Qg6+ Kh8 29.Rh2#.
A.3) 26... Bg7 27.Ne6 Bxe6 28.Bd4 Kf8 29.dxe6, etc.
B) 25... bxa3 26.Qh7+
B.1) 26... Kf7 27.Qg6+
B.1.a) 27... Kf8 28.Rh7 (28.Ne6+ Bxe6 29.dxe6 a2+ 30.Ka1 (30.Kc1 a1=Q#) 30... Bxb2+ 31.Kxb2 a1=Q+ 32.Kb3 Qa3#) 28... a2+ 29.Ka1 + -. B.1.b) 27... Kg8 28.Rh7 is similar to B.1.a.
B.2) 26... Kf8 27.Rg6 a2+ 28.Ka1 + -.
C) 25... Qc4 26.Qxc4 Rxc4 27.Rh5 bxa3 28.b3 Rab4 29.Ka2 Rc7 30.Bxg5 with the better endgame. |
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| Aug-12-11 | | TomOhio: I almost NEVER accept a sacrifice. I'm just not good enough to figure it out ahead. Look at move 27. Nf5 kinds of *looks* like Ne6, but it's not the same. It was important to block the advance of the e-pawn to make this attack effective. See... that's the kind of thing I miss OTB. |
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| Aug-12-11 | | disasternow: This day has already started real catastrophically so why not continue making a fool of myself here too???
No I didn't get this problem...
After some checking I believe that white might even has to fight for a draw in case of 25:Rxh6. @agb2002:
I was actually "experimenting" with 25-,Qc4 myself.
I think there is an improvement in your line!
After 28 b3,... why not 28 ...,a2+ 29Ka1,Bxd4+ 30 Bxd4,Rxd4 31 Rxd4, Rxd4 with a piece up for black? My own idea was:
25 ... , Qc4
26 Qh7+, Kf8
27 Ne6+, Bxe6
28 dxe6, Qd1+
29 Ka2, Rxa3
30 bxa3, Qa1+
31 Kb3 Qxa3#
Comments? |
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| Aug-12-11 | | Patriot: This problem makes my head spin with so many candidates to consider: Bxg5, Qg6, Nb5, Nc6, Ne6, Nf5, b3, Rh6. I wondered if there was some way to trap the rook or go after the king somehow or just win a pawn somewhere. In any case the king is a much higher priority but black could have a dangerous counter-attack starting with ...bxa3. I calculated the entire winning line as in the game but wasn't completely sure since black still had at least one other option (like ...bxa3) rather than accepting the rook sac. I tried to take my own advice about positions like this: calculate each candidate, one by one, even if it looks crazy. Although I probably made too many comparisons and a lot of flipping back and forth making me far less efficient time-wise. I think this puzzle has really earned the title of "Difficult"! |
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| Aug-12-11 | | Patriot: <agb2002> <The black castle looks weak and poorly defended. Hence, open it with 25.Rxh6> Was it really that easy for you to conclude Rxh6 is the key move? If so, I salute you! Because it seems there are so many candidates to consider here. |
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| Aug-12-11 | | Skylark: I thought the correct move was the quiet 25. Qg6. I had the right idea but the wrong move order, it seems. My line went something like <25. Qg6 bxa3 26. Ne6 Bxe6 27. dxe6 Kh8 28. Rxh6+ Bxh6 29. Qxh6+ Kg8 30. Qg6+ Kh8 31. Rh2 mate>, with other variations similarly. Of course, upon seeing the game continuation, cold reality slapped me in the face - <25. Qg6 bxa3 26. Ne6 Bxe6 27. dxe6 axb2 28. Rxh6?? Ra1#> and it is black who walks away with the full point. Argh. And it's not even Saturday yet. It's quite vexing to have the completely correct idea and plan but mess up the execution and have it slap you in the face. |
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| Aug-12-11 | | gofer: Black has an attack that is going to get going pretty quickly, starting with bxa3 semi-opening the b file, so white needs something pretty forcing. <25 Rxh6 ...>
Black cannot accept!
25 ... Bxh6
26 Qg6+ ...
26 ... Bg7 27 Ne6 Bxe6 28 Bd4 Bxe6 29 Kf8 dxe6 mating
26 ... Kf8 27 Ne6+! Bxe6 29 dxe6+ mating
So black must refuse, but what is black's best reply? 25 ... Qc4 26 Qg6 winning
25 ... Bxd4 26 Qg6+! Kf8 (Bg7 Rh7 mating) 27 Bxd4 e5 Qf6+ mating
25 ... bxa3 26 Qh7+ Kf8 27 Ne6+! Bxe6 28 dxe6 mating <25 ... e5?>
<26 dxe6(ep) ...>
26 ... Bxh6+ 27 Qg6+ Bg7 28 Qf7+ Kh8 29 Rh2+ mating
<26 ... Be8>
<27 Qh7+ Kf8>
<28 Nf5! mating)
Time to check! |
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| Aug-12-11 | | kevin86: So sad! I saw Rxh6 first-then I dismissed it for an attempt on black's marooned rook. Shame,everybody knows my name. |
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| Aug-12-11 | | Blunderdome: I was pretty excited about Bxg5. Of course, Black must decline the sac. My engine suggests 25...bxa3 26. Rxh6 axb2 27. Qh7+ Kf7 28. Qg6+, with a perpetual. |
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Aug-12-11
 | | Once: <Patriot: .... Was it really that easy for you to conclude Rxh6 is the key move? If so, I salute you! Because it seems there are so many candidates to consider here.> Funnily enough, Rxh6 was the only move I considered today. It seemed to be the move that the position cried out for. I didn't give a second thought to the alternatives - the job today was to work out the details after 25. Rxh6. And that got me to thinking why. Why should 25. Rxh6 "pop" out of the position as if it was illuminated in neon? I think the answer (for me at least) goes something like this... The key weakness in the black position is congestion and king windiness. The black army is huddled over on the queenside and will take quite some time to get back to the defence of their king. That suggests that white should be looking for a kingside attack. And in turn that suggests that we need a queen entry square. Her majesty needs to gatecrash the black party screaming "I'm coming up, so you'd better get this party started." And that means that Qg6 screams out for attention ... and shortly after that Rxh6 so that Qg6 comes with check. The Bg7 is black's only defensive piece, so if I can draw that away I must be doing well. |
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| Aug-12-11 | | Archswindler: <TomOhio: I almost NEVER accept a sacrifice. I'm just not good enough to figure it out ahead.> There are many good reasons to decline a sacrifice, but that is not one of them. |
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| Aug-12-11 | | Patriot: <Once> Thanks very much for the response! This is precisely what I was looking for. Whenever there are a lot of forcing candidates, it is very helpful to apply that kind of positional knowledge to help narrow down the list of candidates. After reading your response I realized something else in the position that is basic strategy--opposite side castling. Whenever this occurs both players must be vigilant about attacking the other player's king. Plus I agree about black's pieces being away from the defense of the king. That's another good reason to start looking for a kingside attack. Bxg5 also starts activity there but is clearly not as threatening so Rxh6 is the most logical move to look at first. I've often found it helpful to sort of glaze over a list of candidates about 3 ply to see if anything stands out and only after that start comparing moves and digging a little deeper. But here the position suggests "Forget about trapping the rook and all the other strong moves--focus on the king!" |
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Aug-12-11
 | | chrisowen: <Kevin86> Bezier and Bezier the white rook also has time to trough le dark see h6 eg it in thinking that nice ne6 drawing bishop down choc block 28.Bd4 melt ea black defence. |
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| Aug-12-11 | | David2009: G Pirisi vs E Szalanczy, 1981 White 25? Interesting race between two strong attacks. 25.Bxg5 looks too slow: 25...bxa3 threatening 26...Rxd4. Instead
try 25.Rxh6 Bxh6 26.Qg6+ Bg7 27.Ne6 Bxe6 28.Bd4 GOOT! and use Crafty End Game Trainer to look at variations. My analysis only
scratches the surface but I've come to the puzzle very late - it's late at night over here. Time to
check:
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Good start - how the game ended! Puzzle position
click for larger view
and link to Crafty EGT: http://www.chessvideos.tv/endgame-t...
The ever-prudent EGT offers a Queen exchange with 25...Qc4 and I just have time to blunder the game away before going to bed. I'll catch up with the kibitzes in the morning. I’m sure you will all be more successful in piloting White to a well-deserved victory, with or without silicon help, against the EGT. |
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| Aug-12-11 | | agb2002: <Patriot: <agb2002> <The black castle looks weak and poorly defended. Hence, open it with 25.Rxh6> Was it really that easy for you to conclude Rxh6 is the key move? If so, I salute you! Because it seems there are so many candidates to consider here.> I have nothing to add to <Once> response, except that Black was also posing threats and this means that you should consider only forcing moves. Therefore, 26.Rxh6. The rest is calculation to estimate its expectancies of success. In such positions, I only consider other options if the move suggested by the logical analysis turns out to be dubious. |
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| Aug-12-11 | | abuzic: 24.Qd3 posed many problems for black, maybe 24...Rf8 offers the best defence. Black chose 24...b4 and threatened bxa3, but allowed Qd3 to fully function with unexpected sac: 25.Rxh6!. After 24.Qd3, computer engines (Rybka, Fritz, Crafty and Houdini) for few seconds give 24...b4 as the first choice with =, then change "mind" to 24...Rf8  as the best defence, and dropped 24...b4 to near the bottom of choices, obviously after discovering the power of Rxh6!. At the same time after 24...b4, white's choices are limited to 25.Rxh6! with direct mating attack or 25.Qb3 with strong position; other moves lead to equal or inferior postion for white. After 25.Rxh6! black has no defence against mate threats. One line is 25...Qc4 26.Qh7+ winning: (<gofer: Black has an attack ....... <25 Rxh6 ...> Black cannot accept! So black must refuse, but what is black's best reply? 25 ... Qc4 26 Qg6 winning> but 26.Qg6?? bxa3!, or even 26...Qf1+ and white will suffer) So after 25...Qc4: 26.Qh7+ Kf8 27.Rg6 Qf1+ 28.Ka2 Qc4+ 29.Nb3 Rxa3+ 30.bxa3 Qc3 31.Bd4 Ke8 32.Rxg7 Kd8 33.Rxe7 Qxc2+ 34.Rxc2 Rxc2+ 35.Kb1 bxa3 36.Bb6+ Kc8 37.Qxc2+ Kb7 38.Rxd7+ Ka6 39.Qc4+ Kxb6 40.Qc6# Can black announce mate in 16 after 24...b4? it seems so.. |
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Aug-12-11
 | | ajk68: Why is this the Old line? Where does that branch begin? What is the new line? |
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| Aug-12-11 | | Skylark: <ajk68> The system involving 9. Bc4 and 11. h4 is the old line. I believe the new line goes 9. O-O-O and 10. Kb1 but I'm not a complete theory nut. |
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| Aug-12-11 | | TheBish: G Pirisi vs E Szalanczy, 1981 White to play (25.?) "Difficult"
It almost looks like the black rook on a4 can be trapped, but that's an illusion. The king is the thing! 25. Qg6 is too slow; 25...Be8 allows Black to defend. But White has a way to crash through with tempo. 25. Rxh6!!
I don't think I've seen this game before, but I couldn't get past this move when I saw the idea -- maybe because it's crushing! Black pretty much has to accept the sac, because White threatens 26. Qh7+ Kf8 (or 26...Kf7 27. Qg6+ Kf8 28. Rh7) 27. Rg6 with a mating attack. 25...Bxh6 26. Qg6+ Bg7
It would be silly for Black not to save the bishop, but if 26...Kf8 27. Qxh6+ Ke8 (27...Kf7 28. Qh7+ transposes) 28. Qh8+ Kf7 29. Qh7+ Kf8 30. Ne6+ Bxe6 31. dxe6 Ke8 32. Qg8#. 27. Ne6 Bxe6 (forced) 28. dxe6, threatening both 29. Qf7+ Kh8 30. Rh2+ Bh6 31. Rxh6# and 29. Bd4, so if 28...d5 (stopping Rh2) 29. Bd4 and there is no defense. Black's best here (after 28. dxe6), other than resigning, would be 28...Qxc2+ 29. Rxc2 Rxc2 30. Bd4, when White will mate after a couple of spite checks. Speaking of checks, it's time to! |
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| Aug-12-11 | | TheBish: Well, my way still wins, but turns out that 28. dxe6 wasn't necessary. 28. Bd4! is much more to the point. Then if 28...Kf8 29. dxe6, or even 29. Bxg7+ Kg8 30. Bh6+ Kh8 31. Qg7#. |
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Aug-12-11
| | LIFE Master AJ: 25.RxP/h6!! was the only move ... it was also the only real possible sack ... |
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| Aug-13-11 | | dufferps: Very neat. 25. Rxh6 buys a tempo, thus preventing black from advancing pawn to e5 which would block the Bishop from moving to d4 to protect the Queen's mating capture at g7.
I could see it after the game, but not at the time of move 25. So now I have to think about what would happen if white had started his final attack with 25. Ne6.
25. Ne6 Bxe6,
26. Qg6 Bxd5
27. Bd4 e5 (and the attack is blocked)
That Rxh6 tempo move was a necessary key move. |
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Aug-13-11
| | LIFE Master AJ: I teach all of my students to ISOLATE THE PRIMARY TACTICAL THREAT! What this means is to find the most forcing moves, or the biggest threat your opponent has. 
click for larger view In the position afer 25.RxP/h6!!, White has some strong tactical ideas. For example, if 25...b4xa3; then 26.Qh7+ Kf7; 27.Qg6+ Kf8; 28.Rh7, and Fritz shows its mate in 5 or less. One of the main points to consider is that the position is cut in half. Black ... even with best play ... cannot get any of his Q-side pieces back to the King-side to assist in the defense. |
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| Aug-13-11 | | agb2002: <disasternow: This day has already started real catastrophically so why not continue making a fool of myself here too??? No I didn't get this problem... After some checking I believe that white might even has to fight for a draw in case of 25:Rxh6. @agb2002:
I was actually "experimenting" with 25-,Qc4 myself.
I think there is an improvement in your line!
After 28 b3,... why not 28 ...,a2+ 29Ka1,Bxd4+ 30 Bxd4,Rxd4 31 Rxd4, Rxd4 with a piece up for black? My own idea was:
25 ... , Qc4
26 Qh7+, Kf8
27 Ne6+, Bxe6
28 dxe6, Qd1+
29 Ka2, Rxa3
30 bxa3, Qa1+
31 Kb3 Qxa3#
Comments?>
My move 26.Qxc4 is a blunder which spoils practically all the advantage. However, the simple 26.Qh7+ Kf8 27.Rg6 as in my line B.2 wins. Thank you! |
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Sep-02-11
 | | perfidious: This is a prosaic Sicilian Dragon with both sides going at the other's king full on, though the lovely finish beginning with 25.Rxh6 is anything but humdrum. A masterly effort by the winner. |
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