Sep-10-14
 | | al wazir: Why didn't white play 17. Nf7+ ?
Why didn't black play 26...Nh4+ ? |
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| Sep-10-14 | | Lighthorse: I figured the main theme, but I had to think through the variations. You have to keep the white King from escaping to e2, and so either Ba6 planning to move the b-pawn to let the bishop block e2, which didn't seem to work, or more directly Qf5+ I worked through the part where the King takes the black Bishop:27...Qf5+ 28.Kxg3 Qg4+ 29.Kh2 Nh4 [white has some checks that get nowhere] 30.Rg1 Nf3+ 31.Kh1 Qh3# Trickier is if white declines the Bishop with 28.Kg2, but then 28...Nh4+ mates a few different ways: 29.Kg1 Bh2+ 30.Kxh2 Qg4 transitions to the previous mate above
29.Kh1 Qf3+ 30. Kg1 Qg2#
29.Kh3 Qg4# |
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| Sep-10-14 | | Steve.Patzer: Likely the reason black did not play 26....Nh4+ is that he needed more time to consider the move. It is exactly the same position when he moved 28....Nh4+ |
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| Sep-10-14 | | Lighthorse: To <al wazir>:
17.Nf7+ Rxf7 (the Queen protects it).
If you meant 25...Nh4+, then the white King escapes to e2. If you meant why didn't he make the move sooner instead of repeating, maybe he didn't see it, or maybe it was near the time control of 30 moves, and so he was trying to get 2 extra moves in quickly while thinking. |
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Sep-10-14
| | al wazir: <Lighthorse: 17.Nf7+ Rxf7 (the Queen protects it).> My bad. I must have been looking at the position after 17. Bc4 and thinking it was white's move. |
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Sep-10-14
 | | agb2002: Black is two pawns ahead.
Black can deliver mate by incorporating the knight into attack after a short queen maneuver to avoid the flight of the white king, 27... Qh5+: A) 28.Kxg3 Qg4+ 29.Kh2 Nh4 and mate in four (30.Ng5+ hxg5 31.Bg8+ Rxg8 32.Rg1 Nf3+ 33.Kh1 Qh3#). B) 28.Kg2 Nh4+
B.1) 29.Kxg3 Qg4+ 30.Kh2 Qg2#.
B.2) 29.Kh3 Qg4#.
B.3) 29.Kg1 Qf3 and mate in three.
B.4) 29.Kh1 Qf3+ 30.Kg1 Qg2#. |
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Sep-10-14
 | | patzer2: My pick was 27...Rxf7+! for this Wednesday puzzle. It wins (Fritz's second choice) but is not as strong as the game continuation 27...Qh5+!! Looked at 27...Qh5+!! but dismissed it too quickly after visualizing 28. Kxg3 Qg4+ 29. Kh2 Nh4 30. Rg1 (position below). 
click for larger viewWhat I missed here is the mate 30... Nf3+ 31. Kh1 Qh3#. P.S.: Easy to see the mate-in-two after 30. Rg1, but finding it five moves ahead after 27. Kf3 is more difficult. |
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| Sep-10-14 | | morfishine: Like <patzer2> I started out with <27...Rxf7> but found things murky after 28.fxg3 Ne5+
29.Kf4
I then focused on <27...Qxh5+> but unlike <patzer2> quickly found the forcing win Line (1): (1) 28.Kxg3 Qg4+ 29.Kh2 Nh4 30.Rg1 Nf3+ 31.Kh1 Qh3#
However, unlike <patzer2>, I had problems with 28.Kg2 in Line (2) specifically 29.Kg1 but once I found 29...Qf3, all was clear (2) 28.Kg2 Nh4+ 29.Kg1 Qf3 and Black forces mate at <g2> ***** |
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| Sep-10-14 | | gofer: <27 ... Qh5+ >
Running doesn't work...
28 Kg2 Nh4+
29 Kg1 Bh2+! (29 Kh1 Qf3+ 30 Kg1 Qg2# or 29 Kxg3 Qg4+ 30 Kh2 Qg2#) 30 Kxh2 Nf3++ (31 Kh1 Qf3+ 32 Kxh2 Qg2#)
31 Kg2 Qg4+ (Kg3 Qg4#)
32 Kh1 Qh3#
Fighting loses too!
<28 Kxg3 Qg4+>
<29 Kh2 Nh4>
click for larger viewWhite has 35 (?) moves that lose instantly to Qg2#
White also has two spite checks...
1 Bxf5+ Bxf5
2 Ng5+ hxg5
But eventually Rg1 is going to be played and that leads to 30 Rg1 Nf3+
31 Kh1 Qh3#
~~~
Yep, nice Wednesday level POTD...
Ironically, I missed the actual game continuation, but it was hardly
the best defence! |
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| Sep-10-14 | | diagonalley: well... clearly the white K has to be kept out of K2 and the only way to achieve that is 27... Q-R4+ but the continuations are not particularly easy to visualise... quite hard for a wednesday |
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Sep-10-14
 | | Once: There's a certain amount of latent humour in this position. This is the position after 26. Kg2. It's also the position after 28. Kg2 
click for larger viewAs we have seen, the winning move here is 28.... Nh4+. Or 26...Nh4+. But black twice misses it. So the first question has to be why he didn't see it. I suspect that the reason is partly psychological. It feels wrong to be parking a knight in front of our wonderfully attacking queen. But the other reason is possibly because black didn't see how to deal with 29. Kg1. Or 27. Kg1: 
click for larger viewThere are several ways for black to win from here. But black might have been blinded by the "logical" 27...Nf3+ 28. Kg2 
click for larger viewThis may seem logical because it gives check and it moves the seemingly awkwardly placed knight. And indeed Black does win comfortably by snaffling material. But there isn't a quick mate on the horizon. This why, I think black repeated the position. 27. Kg1 or 29. Kg1 shouldn't worry us, as long as we don't get fixated on moving the knight first. Instead Qf3 threatens an unstoppable mate on g2. Fritz also finds mates after Bh2+, Qg4 and Bf4. The ironic thing is that black probably spent ages worrying about Kg1, and then white doesn't play it. Instead white falls on his sword with 29. Kh3? allowing a mate in one. So many of the things that we worry about in life never actually happen. Although that is not a good guiding principle for a chess player... |
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| Sep-10-14 | | Nick46: If white was going to be finished off next move, come what may, he might at least have captured the black bishop as a "baroud d'honneur". |
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| Sep-10-14 | | Cheapo by the Dozen: I'm sure we all saw the start of the line, but I didn't calculate correctly, and hence didn't solve the problem. |
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| Sep-10-14 | | M.Hassan: "Medium/Easy"
Black to play 27...?
Black is two pawns down.
I noticed that the White King has to be deviated from diagonal d1h5 because if the King can access e2 square, has found an escape route and will be safe afterwards. Furthermore, if it were White's move, Black Queen would have been lost by placing the Rook on h1.So, these two factors dictate that the Queen has to give a check on h5 to accomplish deviation as well as putting the Queen in a safer square. 27.............Qh5+
A)
28.Kxh5 Qg4+
29.Kh2 Nh4 threatening mate on g2
30.Rg1 Nf3#
B)
28.Kg2 Nh4+
29.Kxg3 Qf3+
30.Kxh4 Qg4#
<29.Kg1 Qf3 30.fxg3 Qg2#> |
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| Sep-10-14 | | M.Hassan: <al wazir:Why didn't black play 26...Nh4+ ?> 26...........Nh4+
A)
27.Kxg3 Qg4+
28.Kh2 Qg2#
B)
27.Kh3 Nf3+
28.Kxg3 Qg4#
INDEED! Why did'nt Black play 26...Nh4+? |
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| Sep-10-14 | | M.Hassan: Correction:
My line A) should read:
28.Kxg3 and not <Kxh5> |
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Sep-10-14
 | | Penguincw: Tricky puzzle, but I got 27....Qh5+. :) |
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| Sep-10-14 | | awfulhangover: After I found 27.- Qh5+ I saw mate in all variations. A nice feeling if I had been black and Caruana white ... |
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Sep-10-14
 | | Bubo bubo: The white king is about to escape via e2, therefore 27... Qh5+ suggests itself: If White plays 28.Kxg3, then 28... Qg4+ 29.Kh2 Nh4 with the decisive dual threat of Qg2# or Nf3+ and Qh3#. Otherwise 28.Kg2 Nh4+ and now a) 29.Kh3 Qg4#, b) 29.Kxg3 Qg4+ 30.Kh2 Qg2#, c) 29.Kh1 Qf3+ 30.Kg1 Qg2# or finally d) 29.Kg1 Qf3 with unpreventable mate on g2. |
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Sep-10-14
 | | kevin86: black must prevent an escape: therefor Qh5+ |
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| Sep-10-14 | | GreenLantern: Move 27 for Black is an interesting position (which I did not solve :-() 
click for larger viewMost engines I tested on an 8-core failed to find the forced mate starting with 27...Qh5+. With the exception of Houdini and Crafty(!), engines favored 27...Bxe6 - and that includes Stockfish 5 and Rybka 4.1. I believe it is because 28.Kg2 is incorrectly evaluated as 0.0 due to repetition. White does play Kg2 three times (moves 24, 26, and 28). The resulting positions are similar, but not quite equal and I don't believe a draw by repeated positions can be claimed. Maybe even engines got this wrong. |
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| Sep-10-14 | | dfcx: 27... black to move, black is ahead in material by two pawns, even better the white king is exposed. The first priority is to prevent the king from escaping. 27...Qh5+
28.Kxg3 Qg4+ 29.Kh2 Nh4 30.Rg1 Nf3+ 31.Kh1 Qh3#
or 28.Kg2 Nh4+ 29. Kg1/Kh1 Qf3 and mate next (after mate delay checks by white). |
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| Sep-10-14 | | BOSTER: <awfulhangover:A nice feeling if I had been black>. This is the pos. white to play 19.
click for larger view If white would play here <crazy> 19.Qd1 with threat Qh5 I'm not sure a bout your <nice feeling>. |
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| Sep-10-14 | | Fabrizio Vanzan: Several surprising mistakes from both sides, I think it was probably a blitz game |
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| Sep-10-14 | | plumbst: Medium-Easy. Black is up two pawns. Black's bishop is under attack. White's king is in an uncomfortable position, but ♔e2 must be prevented. Therefore, 27...♕h5+!
28.♔g2
[28.♔xg3 ♕g4+ 29.♔h2 ♘h4 30.♘g5+ hxg5 31.♗g8+ ♖xg8 32.♖g1 ♘f3+ 33.♔h1 ♕h3#] 28...♘h4+ 29.♔g1
[29.♔xg3 ♕g4+ 30.♔h2 ♕g2#; 29.♔h3 ♕g4#; 29.♔h1 ♕f3+ 30.♔g1 ♕g2#] 29...♗h2+! 30.♔xh2
[30.♔h1 ♕f3+ 31.♔xh2 ♕g2#]
30...♘f3+ 31.♔g2
[31.♔g3 ♕g4#]
31...♕g4+ 32.♔h1 ♕h3# |
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Kibitzing
