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Jul-15-11
 | | agb2002: White is a pawn down.
Black threatens 20... Nxd2.
All white men aim at the black castle but they haven't posed concrete threats yet. This suggests 20.Rf7: A) 20... Nxd2 21.Rxg7+ Kh8 22.Bd4
A.1) 22... Qc8 23.Rxg6+ Kh7 24.Rg7+ Kh8 25.Rxe7+ Kg8 26.Nf5 and the menace 27.Nxh6# will cost the queen, leaving White a bishop ahead. A.2) 22... Qb5 (trying eventually ... Qf1#) 23.Rxg6+ Kh7 24.Rg7+ Kh8 25.Rxe7+ Kg8 26.Rg7+ Kh8 27.Rxc7+ Kg8 28.Rg7+ Kh8 29.Rxb7+ Kg8 30.Rxb5 + - [B+N+2P]. A.3) 22... Qa4 23.Rxe7+ (23.Rxg6+ Qxd4+ 24.Nxd4 Nxg6 - +) 23... Kg8 (23... Qxd4+ 24.Nxd4 + - [N vs P]) 24.Rg7+ Kh8 25.Rxg6+ Kh7 26.Rg7+ Kh8 27.Rxc7+ Kg8 28.Rg7+ Kh8 29.Rxb7+ Kg8 30.Nf5 Qxd4 31.Nxd4 + - [N+2P]. A.4) 22... Qd(e)8 23.Rxe7+ Kg8 24.Rg7+ Kh8 25.Rxg6+ Kh7 26.Rg7+ Kh8 27.Rxc7+ Kg8 28.Rg7+ Kh8 29.Rxb7+ Kg8 30.Nf5 as above. A.5) 22... Nf5 23.Rxd7+ Nxd4 24.Nxd4 + - [N vs P].
B) 20... Rg8 21.Qc3 Ne5 22.Rxg7+ Kh8 (22... Rxg7 23.Nf8+ and 24.Nxd7 + -) 23.Rf7 (the knight on e5 is pinned) + - [B vs P]. C) 20... Qxe6 21.dxe6 (21.Rxg7+ Kxg7 22.Qc3+ Qf6 23.Bd4 Ne5 - +) 21... Nxd2 22.Bxd2 C.1) 22... Nd5 23.c4
C.1.a) 23... Nb6 24.Bc3 Rg8 25.Rxc7 with the threats Nxe4, Rxb7 and e7. C.1.b) 23... Nf6 24.Bc3 Ne8 25.Nxe4 and White looks much better. For example, 25... Kg8 26.Bxg7 Nxg7 27.Nf6+ Kh8 28.e7 followed by 29.Rf8+. C.2) 22... Nc6 23.Nxe4, again with the better prospects. C.3) 22... Nf5 23.Nxf5 gxf5 24.Bc3 Rg8 25.e7 wins. |
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| Jul-15-11 | | gofer: I would guess that white sacrifices the queen to get a foothold on f7. The queen sac is
fine because white can immediately create a horrid discovered check along the a1-h8
diagonal.
<20 Rf7 ...>
20 ... Nxd2
21 Rxg7 Kh8
22 Bd4 ...
22 ... Nc4 23 Rxe7+ Ne5 24 Bxe5+ dxe5 25 Rxd7 winning 22 ... Qxe6 23 dxe6 Nf5 24 Nxf5 gxf5 25 Rxc7+ Kg8 26 Rg7+ Kf8 27 Bf6 Re8! 28 e7+ Rxe7 29 Rxe7 winning 22 ... Nf5
23 Rxd7+ Nxd4
24 Nxd4 ...
White has won a piece and has a strong foothold on the seventh rank. So I would say
that black has lost this and cannot accept the queen sacrifice and must instead
support Bg7. The refusal is much more interesting Qc3 or Qd4 or Rxg7 and Nf8+.
There are so many choices, I looked at Rxg7 Rxg7 Nf8+ which is much simpler to
follow, but less fruitfull. I prefer the slow build up. Then I read <Catfriend>'s line
and it is very simple, which is why Black must take the queen! |
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| Jul-15-11 | | sevenseaman: Its a beautiful combination but I did not quite see the way it has gone. I considered 20. Rf7 but then the hanging Q distracted me. |
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| Jul-15-11 | | sevenseaman: Solvers who can ignore the hanging White Q to play 20 Rf7 today are really strong chess players.
After contemplating 20. Rf7 I tried a funny approach that soon ran my solution into the ground. 20. Qc3 Bxc3 21. Nf8+ Kg7 22. Nxd7 and was then all at sea. |
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| Jul-15-11 | | waustad: A Friday puzzle that I actually saw. That's rare for me. OTB I would never have had the the nerve to do it. |
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| Jul-15-11 | | Creg: My thought process began with; "How can I use the dark diagonal?" I wanted to put the Queen on c3 or d4, but black's bishop covered that line. So I thought, what if I pin the bishop with 20.Rf7. I lose the queen with 20...Nxd2, but after 21.Rxg7+ Kh8 22.Bd4, white should be able to cause a lot of damage with the endless discovered checks. |
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Jul-15-11
 | | al wazir: What happens after 23...Nc6 ? If 24. Bc3, then 24...Nb1; if 24. Bf6, then 24...Rf8. |
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| Jul-15-11 | | benbook: Rook f7 and its over whether the black knight takes the queen or not,as once the black bishops been taken with a check and the king moves to h8,whites got bishop d4 and from there on its simple..im guessing there's a better way to do it,but im unable to see it if there is..in fact quite a few ways to finish black off...fairly easy for a friday |
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| Jul-15-11 | | kevin86: Complicated:white gives up the queen and then frces black to return it...and wins later. |
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| Jul-15-11 | | tacticalmonster: 20 Rf7 Nxd2 21 Rxg7+ Kh8 22 Bd4 Nf5 23 Rxd7+ Nxd4 24 Nxd4  |
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| Jul-15-11 | | David2009: A Drvota vs Z Szymczak, 1978 White 20? I am guessing that Black, under pressure, has incautiously just played 19...Nc4 allowing 20.Rf7 Nxd2 21.Rxg7+ Kh8 22.Bd4 threatening Rxe7+ GOOT!
Time to check:
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Well, I guessed right. Here's the puzzle position:
click for larger view
with a link to Crafty End Game Trainer: http://www.chessvideos.tv/endgame-t... Black went badly wrong at move 23: with 23...Nc6 he can put up tough resistance. Second time around I managed to win starting 24.Bc3 Nb1 25.Bf6 Rb8 26.Rxg6+ Kh7 27.Rg7+ Kh8 28.e7 Nxe7 29.Rxe7+ Rxf6 30.Nxe4 Rg6 31.Rxc7 d4 32.Nc3 Nxc3 33.Rxc3 Rb6 34.b3 Kg7 35.Kf2 Kf6 36.Ke3 Ra6 37.Kd4 Rxa2 38.Kxd5 Ra4 39.Rc5 Rxc5!? 40 Kxc5 Ke4
and White wins the Pawn ending
click for larger viewEarlier (move 19) Black misses 19...c6! and if 20.Nxg7 Nxd5 looks good for Black. Further EGT link to the position at move 18: http://www.chessvideos.tv/endgame-t... Time to read the other kibitzes (later): (apologies if I have duplicated other comments, in haste, we have guests). |
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Jul-15-11
 | | Jimfromprovidence: There is a lot of subtlety to this puzzle. The first thing I noticed in this regard is that white must play 23 dxe6 instead of 23 Rxe7+ to maximize his advantage.
click for larger view
This move keeps the discovered check threat intact, specifically threatens 24 Rxe7+, and creates a powerful passed pawn. As <al wazir> and <David2009> have stated, 23…Nc6 is black’s best move here. 24 Bc3 is a winning follow-up, but 24 Bf6 looks even better.
click for larger viewOne specific threat is a mating net, beginning with 25 Rxg6+ Kh7 26 Rg7+ Kh8 27 Rf7+, etc. Also, with the bishop at f6, white now has support for the advance e7. One possible continuation is 24… Rf8. White now has 25 Rxg6+ Kh7 26 e7, winning a piece for a pawn.
click for larger view |
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| Jul-15-11 | | CHESSTTCAMPS: White is down a pawn a pawn and faces a nasty knight fork. If white is intent on saving the queen, play might continue 30.Qe2?? Nxe3 31.Qxe3 (Nxg7 Nxf1) Nxd5 32.Qxe4 Nf6 33.Qe1 (Qc4 d5) Re8 and the destabilized knight falls. White must use his assets, the strongly posted knight and the active rook, to maximum advantage: 20.Rf7! and it quickly becomes clear why the WQ is expendable. A) 20... Nxd2 21.Rxg7+ Kh8 22.Bd4!
The key idea, a windmill. White can play for a win or fall back on a draw by perpetual check if a win is not there. There are several defenses to consider: A.1) 22... Qa4?
Sometimes the best defense against a windmill is to attack the piece delivering the discovered check. This move sets a trap, but is not the best. 23.Rxe7+ Kg8 (23... Qxd4 24.Nxd4 is winning) 24.Rg7+ Kh8 25.Rxc7+ Kg8 26.Rg7+ Kh8 27.Rxb7+ Kg8 28.Rg7+ Kh8 29.Rxg6+! (Rxa7+?? - the trap - Qxd4+! 30.Nxd4 Rxa7 and black appears to be winning) Kh7 30.Rg7+ Kh8 31.Nh5! (playing for an Arabian) Qxa2 (black is defenseless - only Qxd4 stops mate) 32.Re7+ Kg8 33.Nf6+ Kh8 34.Rh7# A.2) 22... c5 23.Rxe7+ cxd4 24.Rxd7 Rc8 25.Re8+ leaves white an easy ending. A.3) 22... Qxe6 (apparently best) 23.Rxe7+ (dxe6 Nc6! 24.Rd7+ [24.Bc3 Nb1!] Kg8! appears to hold, but not Nxd4 25.e7 Re8 26.Rd8) Qe5! 24.Bxe5+ dxe5 25.Rxe5 Rd8 26.b3 (intending c4) b5 and I doubt that white can win. A.4) 22... Other queen moves play similarly to A.1 with a win for white. B) 20... Rg8? 21.Qd4 Ne5 (Nf5 22.Rxd7 wins) 22.Rxg7+! Rxg7 23.Nf8+ wins. C) 20... Qxe6 21.dxe6 Nxd2 22.Bxd2 Nf5 23.Nxf5 gf 24.Bc3 Rg8 25.e7 wins. C.1) 22... Nc6 23.Bc3 Rg8 24.e7 wins.
Based on A.3, I think black has drawing chances with best play but I'm probably missing something. Time for review... |
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| Jul-15-11 | | Patriot: I wanted to spend about 2 minutes on this and ended up spending 3 minutes. I calculated 20.Rf7 Nxd2 21.Rxg7+ Kh8 22.Bd4, setting up a "windmill". Also, 22.Bd4 is necessary to prevent removal of the guard by 22...Qxe6 23.dxe6 Kxg7. I also considered 22.Bxh6 but that seemed very weak by comparison. 22...Nf5 didn't concern me because of 23.Nxf5 or 23.Rxd7+. |
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| Jul-15-11 | | CHESSTTCAMPS: Well, I'm anticipating Crafty's defenses, which is either a sign of progress or defeatism. I saw posts from <David2009> and <Jim> that show my bracketed inner note in A.3 is in fact the way to go. Congrats to <David2009> for finding the win! |
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| Jul-15-11 | | DrMAL: Yes, 23...Nc6 is better than 23...Nf5 since it cannot be taken immediately but 24.Bf6 simply reinstates its threat and black is still hopelessly lost. Not sure why there is so much engine output on this, whatever LOL, cheers. |
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Jul-15-11
 | | ajk68: Is there a win after 20. Rf7 Qxe6, ? |
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| Jul-15-11 | | Shams: <ajk68> 20.♖f7 ♕xe6 21.♖xg7+! Δ ♕c3 |
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| Jul-15-11 | | DrMAL: Well, 20...Nxd2 was best (and loses). After 20...Qxe6 there follows 21.dxe6 Nxd2 22.Rxe7 and either the knight on d2 is taken (winning) or it moves and 23.Bd4 wins (e.g., 23...Ne5 24.Bxe5 dxe5 25.Nxe4 with Rxc7 and e7 to follow), cheers. |
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| Jul-15-11 | | Shams: Yeah, <DrMAL> is correct; I saw that line too but didn't see that my line fails to the simple 21...Kxg7 22.Qc3+ Qf6 23.Bd4 Ne5 |
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| Jul-15-11 | | DrMAL: I got the numbering wrong (should have been 22...Ne5 23.Bxe5 dxe5 24.Nxe4) helps to use a computer! LOL, cheers. |
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| Jul-15-11 | | smitten: To me Black's move 18..Rxf1 looks like a mistake, followed by 19..Nc4 - no reason for him open up the f-file for White. |
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| Jul-15-11 | | wals: Rybka 4 x 64 : d 25 : 1 hr 38 min :
1. (4.13): 20.Rf7 Qxe6 21.dxe6 Nxd2[] 22.Rxe7[] Kg8 23.Bxd2[] d5 24.Rxc7 Re8 25.Rxb7 Rxe6 26.Ne2 d4 27.Rd7 e3 28.Bc1 h5 29.a4 Be5 30.c3 dxc3 31.bxc3 a6 32.Rd3 Rb6 33.Rxe3 Bf6 34.Kf2 Kf7 35.Rf3 19...Nc4, +4.13, was Black's undoing.
Better was c6, +0.90.
23...Nf5, +8.61 iced the cake for White.
Black resigned after 26.Rg7+. |
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| Jul-15-11 | | gofer: I played this against Crafty and he finds quite a nice resource for black. Rf7 Nxd2
Rxg7+ Kh8
Bd4 Qxe6
dxe6 Nc6!
If the bishop moves to f6 immediately Nd2 gets off easy, so we make his life more difficult! Bc6 Nb1
Bf6 Rf8
Rxg6+ Kh7
Rg7+ Kh8
Rf7+ Kg8
Rxf8+ Kxf8
Nxe4 ...
Nb1 is stuck! The problem with d5 freeing the knight is that fatally weakens Pb7 and Pc7! ... Ke8
Kf2 ...
starting to hunt down the knight!
... Ke7
Kd1 Kxe6
Kc1 Na3
bxa3 Kf5
Nf2
Game over... |
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| Jul-15-11 | | DrMAL: <smitten: To me Black's move 18..Rxf1 looks like a mistake> It isn't, along with 18...Nf5 it is one of the two best moves. 18...Nf5 is a bit sharper and maybe slightly better, depending on style. Other moves are simply not as good (e.g., 18...Nc4 leads to loss of the exchange for a pawn). 19...Nc4 was a losing blunder (as the game shows), probably the only good move here is 19...c6 (where either 20.c4 or 20.Nxg7 are expected) with very small advantage to white. |
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Kibitzing
sac: 20.Rf7