< Earlier Kibitzing · PAGE 3 OF 3 ·
|Jul-23-09|| ||agb2002: Black has B+N+2P for the bishop pair and threatens 23... Re2 and 24... Qa1#. However, the pawn on f7 is pinned, which makes the square g7 even weaker because ... f6 is not possible. This suggests the elimination of the knight, to avoid ... Ne5 closing momentarily the diagonal, with 23.Rxg6:|
A) 23... hxg6 24.Qd4 Qa1+ 25.Kd2 Re2+ 26.Kxe2 Re8+ (26... Bg4+ 27.Kf2) 27.Kd2 Qxd1+ 28.Kxd1 Kf8 29.Qxg7+ Ke7 30.Qf6+ Kf8 31.Qxf7#.
B) 23... Qa1+ 24.Kd2 with multiple threats: 25.Rxa1, 25.Rxg7+, 25.Qd4.
C) 23... Be6 24.Rxg7+ Kh8 25.Rg8+ Kxg8 26.Q(R)g1+ and mate next.
D) 23... Re5 24.Rxg7+ Kxg7 (24... Kh8 25.Qxf8#) 25.Rg1+ Kf6 (25... Kh6 26.Qxf8+ Kh5 27.Bxf7+ Kxh4 28.Qh6+ Rh5 29.Qxh5#) 26.Qd6+ Be6 (26... Kf5 27.Qxe5#) 27.Qxe5+ Ke7 28.Bb4+ followed by 29.Qd6+, etc.
I also considered 23.Qd4 Ne5 (23... Re5 24.Rxg6; 23... Qa1+ 24.Kd2) 24.Rxg7+ Kxg7 (24... Rh8 25.Rxf7 threatening 26.Rxf8+ and 26.Qxe5+ Rxe5 27.Bxe5+ Kg8 28.Rg7+ Kh8 29.Rg8#) 25.Rg1+ Kf6 (25... Kh8 26.Qxe5+ Rxe5 27.Bxe5+ f6 28.Bxf6+ Rxf6 29.Rg8#; 25... Rh6 26.Qf4+ Kh5 27.Qg5#; 25... Bg4 26.Qxg4+ and mate next) 26.Qf4+ Ke7 (26... Bf5 27.Qg5#) 27.Qxe5+ Kd8 (27... Be6 28.Qc7+ Bd7 29.Re1#) 28.Qb8+ Bc8 (28... Ke7 29.Re1+ Be6 30.Qc7#) 29.Qd6+ Bd7 30.Bf6+ Kc8 31.Bxb7+ Kxb7 32.Qxd7+ Kb8 (32... Ka6 33.Qc6+ Ka5 34.Bc3#; 32... Kb6 33.Bd4+ and mate next; 32... Ka8 33.Qd5+ Kb8 34.Be5+ Rxe5 (34... Kc8 35.Qc6+ Kd8 36.Qc7#) 35.Qxe5+ and White will win the other rook but also the white rook is lost after ... Qa1+. Perhaps there is a way to improve this line for White.
Finally, 23.h5 seems to give Black some chances after 23... Re2 24.Rd2 Rfe8 25.hxg6 Qa1+ 26.Kc2 Qa4+.
|Jul-23-09|| ||johnlspouge: Thursday (Medium):
A Sokolov vs Bagirov, 1993 (23.?)
White to play and win.
Material: 2B for B+N+2P. The Black Kg8 has 1 legal move, h8. The White Bc3 x-rays h8 through Pg7. The White Rg1 is on the same file as Kg8, with the Black Pg7 and Ng6 intervening. The White Bd5 pins Pf7 to Kg8. The White Rd8 x-rays the loose Bd7 through Bd5. The White Qc5 attacks Rf8 and although requiring activation, can move along the open 5-th rank, once Bd5 moves. The White Ph4 can advance to attack Ng6. The White Kc1 is vulnerable to 23…Qa1+, which would eventually force Kc1-d2 to avoid perpetual check. At d2, the White K is uncomfortable, but in no immediate danger.
Candidates (23.): Qd4, Rxg6
[23.Qd4 Ne5 is not immediately decisive]
Only Ng6 can guard the dark squares, suggesting the exchange sacrifice 23.Rxg6.
23.Rxg6 (threatening 24.Rxg7+ 25.Rxf7+ 26.Rg7+ 27.Rg8+#)
23…hxg6 [Qa1+ 24.Kd2 drops Qa1] [else, the mate threat]
24.Qd4 (threatening 25.Qxg7#)
In the following, Black can sacrifice his Qa1, to delay but not prevent mate. In fact, Black just has a few checks before expiring:
24…Qa1+ 25.Kd2 Re2+ 26.Kxe2
26…Re8+ [or Bg4+] 27.Kf2 (threatening 28.Qxg7#)
Black has nothing left.
|Jul-23-09|| ||agb2002: <agb2002:
I also considered 23.Qd4
Perhaps there is a way to improve this line for White.>
<OBIT> and <The Bish> seem to have found some improvements.
|Jul-23-09|| ||johnlspouge: Toga indicates a mild improvement in my initial mate threat:|
23.Rxg6 (threatening 24.Rxg7+ 25.Rxf7+ 26.Rxf8#)
|Jul-23-09|| ||johnlspouge: < <agb2002> wrote : < [snip] I also considered 23.Qd4 [snip] Perhaps there is a way to improve this line for White. >|
<OBIT> and <The Bish> seem to have found some improvements. >
Toga evaluates 25.Rxg6 as a forced mate; 25.Qd4, at a mere +10 P or more, along the variations people indicate.
It's nice to see <The Bish> back in form today, after taking a sting from the "<bellringer>" yesterday. Until yesterday, I cannot recall <any> faulty analysis from him. Maybe he was just trying to get his kids out the door too :)
|Jul-23-09|| ||Eisenheim: I'm in the 23 Qd4 camp, but I always manage to make things more difficult, although the mating line seems simple to see here|
|Jul-23-09|| ||fgh: One move, which I haven't seen anyone mention yet, is 23. Qa3. It may work, but I'm not completely sure.|
|Jul-23-09|| ||David2009: <chessgames.com: 23.Qd4 Ne5 24.Rxg7+! Kxg7 25.Rg1+ Kh8 26.Qxe5+! Rxe5 27.Bxe5+ f6 28.Bxf6+! Rxf6 29.Rg8# (Toga) If you saw the line with 23.Qd4 then give yourself full credit> Thanks. You are very kind. However,
I assumed the defense 24 ... Kh8 instead of Kxg7 which I judged would be too loosening for Black: thus <David2009: [snip] 23 Qd4 Nd5 24 Rxg7+ Kh8 25 Qxd5 Rxd5 26 Bxd5 etc> leads to |
click for larger view
On looking at the position as reached, Black (to move) has dangerous checks. The position is far from the clear-cut win I had assumed. I had "forgotten" in analysing from the original position that the B having moved from c3 may allow ... Qa5+. One variation: 26... f6 27 Bxf6 Qa1+ 28 Kd2 Qa5+ and now 29 Ke3 allows Qb6+. Plenty of Black counter-play.
All in all, 23 Rxg6 saves a great deal of trouble.
|Jul-23-09|| ||The Rocket: does h5 also win?|
|Jul-23-09|| ||The Rocket: wasnt yesterdays puzzle more advanced? even though it was also easy.|
what does the computer evaluate?-
|Jul-23-09|| ||Patriot: Patriot: Initial candidates: h5,Rxg6,Qd4
A) 23.h5 Re2 I looked at several candidates and possibilities before seeing this as a response. Let's put this idea on hold and look at the other candidates before going any deeper.
B) 23.Rxg6 hxg6 24.Qd4 It seems that black has only one "defense" (if you want to call it that).
24...Qa1+ 25.Kd2 Re2+ 26.Kxe2 Re8+ 27.Kd2 Kf8 28.Qxg7+
There's not much to look at here. Black doesn't have perpetual much less a counter-attack. The black king is exposed and on the run...the black queen is hanging. This is resignable for black.
This allows some defense and could be more complex. For instance 23...Ne5, although it "could" still be winning for white.
Therefore I chose variation B. My reasoning is the same as the past several days--variation B is more forcing and will definitely win with no complications.
|Jul-23-09|| ||kevin86: I missed this one-BTW,Qd4 is the perfect SECOND move in this combination.|
|Jul-23-09|| ||YouRang: Not too bad, since Qd4 (threatening Qxg7#) is an obvious try. However, it's foiled because black can block with ...Ne5 and then has counterplay with ...Qa1+.|
So, it makes sense to consider taking out the knight via 23.Rxg6!. (Personally speaking, it took me several minutes to make sense, but that's beside the point.)
And after 23...hxg6, then 24.Qd4 becomes a surprisingly difficult mate threat for black to parry, thanks to the pinned f7 pawn. If 24...Qa1+ then 25.Kd2! avoids further checks (or at least helpful ones), and black is hosed.
|Jul-23-09|| ||doubledrooks: I cast my vote for 23. Rxg6, and if 23...hxg6 then 24. Qd4 threatens mate on g7. There seems no way for black to avoid mate or serious loss of material.|
|Jul-23-09|| ||YouRang: <fgh: One move, which I haven't seen anyone mention yet, is 23. Qa3. It may work, but I'm not completely sure.>|
After 23...Qxa3 24.bxa3 isn't white simply worse, being down a couple pawns?
|Jul-23-09|| ||Utopian2020: I first looked at 23. Qd4, but saw that Ne5 would make things difficult. However with the rook at g1 available to take out the knight at g6, I examined that move next. It was very easy to see 23. Rxg6, followed by Qd4 was winning. Perhaps, too easy for a Thursday.|
|Jul-23-09|| ||muralman: Missed M T and W. This one is a good match for my sequential way of thinking. The rook times bishop is obvious if you want to sling the queen in front of the bishop. |
Of course, the H pawn must take the rook, as the other is pinned. The white rook has to be taken, or mate ensues.
|Jul-23-09|| ||Patriot: <YouRang: <fgh: One move, which I haven't seen anyone mention yet, is 23. Qa3. It may work, but I'm not completely sure.>
After 23...Qxa3 24.bxa3 isn't white simply worse, being down a couple pawns?>|
This is still tricky. After 23.Qa3 Qxa3 24.bxa3, the threat is 25.h5 Ne5 26.Rde1 (threatening to win a piece) Nd3+? 27.Kd2 Nxd1 28.Rxg7+ Kh8 29.Rxf7+ Kg8 30.Rg7+ Kh8 31.Rg8#.
But I think the "threat" is swayed with 26...Ng4.
So maybe 24...Be6 is fine, blunting the d5-bishop. For example: 25.h5 Bxd5 26.cxd5 Ne5 27.Rde1 f6. I will definitely check this later with Fritz.
|Jul-23-09|| ||YouRang: <Patriot> You're right, it is trickier than I thought.|
After <23...Qxa3 24.bxa3> [diagram]
click for larger view
White has 2 threats: (1) h5 (as you mentioned) and (2) Bb4 winning the exchange.
However, black can parry both threats with 24...Re3!, which (1) buys time against h5 by attacking the bishop, and (2) frees the previously immobile rook on f8.
White can buy that time back, and maintain the h5 threat, by attacking the rook with 25.Bd4, but then black has 25...Rh8, to save the rook and prevent h5.
|Jul-23-09|| ||mig55: Today I found both the solutions! Also Qd4.|
|Jul-23-09|| ||Patriot: <YouRang>
24...Re3 is a nice find and is best according to Fritz, giving black a 0.68 or so pawn advantage. My idea of 24...Be6 is about a 1 pawn advantage for white!
I think this demonstrates why forcing moves (like 23.Rxg6) should be considered before these quiet type moves (like 23.Qa3).
1) Usually require more calculation and precision.
2) Give the opponent more opportunity to defend or counter-attack.
|Jul-23-09|| ||OBIT: <David2009>In the "party pooper" line after 24. Rxg7+ Kh8, your idea 25. Qxe5 Rxe5 26. Bxd5 is interesting and looks like a win to me. After your suggestion 26...f6 27 Bxf6 Qa1+ 28 Kd2 Qa5+, White has 29. Ke2 and, son of a gun, Black has no useful checks. Note the cute refutation of 29...Re8+ is 30. Re7+, while the cute refutation to 29...Bg4+ is 30. Rxg4+. This is the kind of stuff you usually see only in composed problems.|
When I looked at the party pooper line today, my first impulse was the obvious 25. Rdg1, but 25...Bf5! is an annoying response - now Black threatens Qb1+ as well as Qa1+. Looking for something better, I decided on 25. Qe4:
click for larger view
White threatens mate in one. If Black takes the rook, White can transpose back to the Kxg7 main line with 26. Rg1, but even better is 26. Bxe5+. After 25...Ng6 26. Rxg6+ forces mate. That leaves 25...f5, when 26. Bxe5! Qa1+ (26...fxe5? 27. Rg8#) 27. Kd2 Qa5+ 28. Ke2 and it's over; for example, 28...Rxe5 29. Qxe5 Re8 30. Re7+.
To the folks saying 23. Rxg6 is better than 23. Qd4 because it is simpler: Agreed, but the 23. Qd4 lines are a lot more fun to analyze. :)
|Jul-23-09|| ||WhiteRook48: got it here|
|Jul-23-09|| ||DarthStapler: Got it|
|Jul-23-09|| ||gerpm: Enjoyed the puzzle.|
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