| Jun-02-16 | | patzer2: Saw the double attack 22. Qc2! at blitz speed. With the difficulty of this week's Tuesday and Wednesday puzzles, perhaps today's Thursday puzzle should have appeared earlier in the week. Black's decisive error was 21...Nxe5? allowing 22. Qc2  (+2.90 @ 37 depth, Stockfish 5 SE). Necessary instead was 21...g6 22. Kg2 Nxe5  (0.45 @ 30 depth, Stockfish 240515). Earlier, the computer choice of the simple developing move 9...e6 = (0.08 @ 33 depth, Stockfish 7) seems preferable. |
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Jun-02-16
 | | Penguincw: Yeah, an easy looking Thursday puzzle. Simply 22.Qc2, attacking the rook on c8 for a 2nd time, threatening mate on h7, while the knight on e5 remains hanging. 22...Ng6 is best, 23.Rxc8 results in white being up the exchange, should be winning. I'm trying to see if perhaps earlier in the puzzle,there was a Thursday-level puzzle out there. Well, the sacrifice <cg> lists is 21.Rxc3, doesn't look like an exchange sac to me. One last comment I'd like to make. After 17.Bb1, the pawn on d4 is a poison pawn due to 18.Qd3, attacking the knight and threatening to mate on h7. If 18...Nf5, then 19.g4, winning the piece. |
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Jun-02-16
 | | al wazir: 22. Qc2 was easy to find, and it wins the exchange. At what point were we solvers entitled to stop analyzing and declare the puzzle solved? Play continued for another 25 moves. |
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| Jun-02-16 | | ndg2: Zwischenzug!
Qc2, nuff said |
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| Jun-02-16 | | Cheapo by the Dozen: White is down a knight but can recapture it. That said, 22 Qc2 makes a double threat, of mate at h7 and a rook capture (with tempo) at c8. Black options such as 22 ... Nf3+ or 22 ... Rc3 don't change the basics of the double threat. |
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| Jun-02-16 | | AlicesKnight: What about 22.Qc2 - looks as if it might win the exchange at least...yes, that was it. Black's 17th - 19th moves look futile while White organises. |
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| Jun-02-16 | | gofer: Winning the exchange with <22 Qc2> was easy, not <Medium>! But the win was still a long way off... |
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| Jun-02-16 | | saturn2: I saw Qc2 after about 30 seconds. |
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| Jun-02-16 | | Once: Weird week continues with a fairly easy POTD that doesn't seem up to Thursday medium difficulty. We need to start with a little retrograde analysis. White is down a minor piece, but black's Ne5 is en prise. So presumably black's previous move had been his knight capturing a minor piece on e5. Black probably captured a white knight there, since a bishop on e5 would have been vulnerable to f6. Now the logical thing to do would be to recapture the knight with one of the two prawns. But this is a puzzle and a simple recapture wouldn't be particularly exciting. That's when the cluster of pieces on the c file and b1-h7 diagonal suggests the 22. Qc2 that everyone has spotted. White wins the exchange. Fairly easy to spot because we know it's a puzzle. But I am willing to bet that OTB many players would automatically swap off the knight without looking for zwischenzugs. And, harder still, how many would spot the danger as black? Here's the position before 21...Nxe5: 
click for larger view Capturing white's monster Ne5 seems the most logical thing in the world. If it wasn't for the tactical move 22. Qc2, we would argue that 21...Ne5 was exchanging off pieces, allowing a trade of rooks on the open e file and solidifying white's pawns so that we can attack them. Indeed, if we take the tactic away, Nxe5 is one of Fritz's top picks. For fun, I adjusted the position so that the white bishop was on a2 and not b1: 
click for larger viewFrom here, Fritzie top three picks are Ne7, Bd7 and our old friend Nxe5 - all of which are approximately level. So an easy puzzle - probably around a Tuesday level of difficulty - but probably a Thursday difficulty to spot as black OTB. |
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| Jun-02-16 | | Gilmoy: <17.Bb1 bishop thing> was cute, indirectly defending d4 via the same battery-fork: 17..Nxd4? 18.Qd3 Nf5 19.g4:
click for larger view<20.a3> is adorable: the only thing better than a rook lift is a <rook rubberband recapture>, when you get the lift for "free". This fulfills the checklist for the <double double>: the Q wants to go to the intersection of those two lines. White also has the default plan of Rdc1-b4-b5 to collapse Black's Q-side, so the lift is already a serious threat. Black needs more oomph with her tempi. Allowing the Ne5 to just sit there is probably too passive. |
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| Jun-02-16 | | Patriot: <al wazir> The answer depends on whether you want to be a puzzle solver or a good analyst. A good analyst will look at Qc2 and try to defeat it with moves like Nf3+ but once you see that black is technically lost the job is done unless there's a competing move to Qc2. |
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| Jun-02-16 | | mel gibson: I didn't look at this long enough.
I would have just taken back the knight with one of the pawns.
I tried both ways on the computer & neither was any good.The computer agrees with the text above:
22 Q-c2 score 3.07 depth 20 |
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| Jun-02-16 | | dfcx: White is down a knight. The solution can't be the simple taking back of the knight. Got it!
22.Qc2 "forks" the h2 mate and c8 rook.
22...Ng6 23.Rxc8 up an exchange. |
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| Jun-02-16 | | patzer2: While 42. Qe7 (+4.27 @ 25 depth, Deep Fritz 15) or most any other reasonable move is winning, I was wondering why White didn't go immediately for the pin with 42. Rc8 (+7.10 @ 25 depth) as in the (diagram below). 
click for larger viewThe computer gives best play in this line as 42. Rc8 Qd7 43. Qb8 Qe7 44. Re8 Qa3 45. h5 f5 46. Qd8 Kf7 47. Re5 g6 48. Qxd5+ Kg7 49. hxg6 Nxg6 50. Qxb7+ Kf6 51. Qc6+ Kg7 52. Qd7+ Kg8 53. Re8+ Nf8 54. Qe6+ Kg7 55. Re7+ Qxe7 56. Qxe7+ (#19, Deep Fritz 15). However, after looking at it from a practical perspective as a player OTB under time constraints. I realized 42. Qe7! might be the best alternative for a human player as it takes away the White Queen's defense of the Knight and prepares the Rook pin on c8 to force the exchange of Queens and transition to an easily won ending. If 42...Ne6, to avoid the pin, then simply 43. Rc8+ Kh7 44. Qxf7 as in the (diagram below) with a quick mate to follow: 
click for larger view44...Nf4+ 45.gxf4[] Qc6 46.Qg8+[] Kg6 47.h5+ Kxh5 48.Rxc6[] bxc6 49.Qxg7 Kh4 50.Qxh6+[] Kg4 51.Qg5#[]
(#7, Deep Fritz 15). |
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Jun-02-16
 | | Fusilli: If the point is to win the exchange (and that *is* the point), then it's more like a Tuesday puzzle, isn't it? Nevertheless, clever. How many of us would, in a real game, routinely take back the knight? In real life no one comes to whisper in your ear: "stop and think! You have a winning move!" |
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| Jun-02-16 | | Castleinthesky: Fairly straight forward for a Thursday. The rest of the game looks like Black just hanging on while White makes the most of his material advantage. |
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| Jun-02-16 | | ponaldpuck: Some of these puzzles might technically not give enough information - the possibility of castling, en passant, draw rules, etc. What if Qc2 was the third repetition of the position? Boom, instant draw. I know, the players would have to be morons, and perhaps you can logically deduce that the position after Qc2 cannot possibly be obtained three times in 22 moves, but again, I'm just pointing out a technical possibility. |
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| Jun-02-16 | | kevin86: Instead of recapturing the knight, white double attacks the rook and the mating square at h7...white wins the exchange. |
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| Jun-02-16 | | Gilmoy: <Fusilli: How many of us would, in a real game, routinely take back the knight? In real life no one comes to whisper in your ear: "stop and think! You have a winning move!"> Hence we learn patterns. White clearly prepared the entire sequence starting with <17.Bb1>, so it was already at the top of her mental blackboard. Then <21..Nxe5> counts as a desperado that does not even distract. Ergo: Have a plan (and form a plan). |
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| Jun-02-16 | | agb2002: White is a knight down.
Black threatens 22... Nc4(6).
White can create a double threat with 22.Qc2:
A) 22... Rxc3 23.Qh7#.
B) 22... Ng6 23.Rxc8 wins the exchange with an overwhelming position. C) 22... Nf3+ 23.Kg2 f5 24.Rxc8 Qb6 25.Qc3 (probably better than 25.Rxe8 Nh4+ 26.gxh4 Rxe8 27.Qc3) 25... Bh5 26.Rxf8+ Kxf8 27.Rd3 (27.Bd3 Nh4+ 28.gxh4 Bxd1) followed by Bc2-d1. D) 22... f5 23.Rxc8 Nf3+ (23... Qb6 24.fxe5 + - [R]) transposes to C. |
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| Jun-02-16 | | BOSTER: White has three possibilities to take the knight on e5.
But correct solution is 22.Qc2 with double attack the threat Qh7# and Rxc8. |
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| Jun-02-16 | | Steven87: 41. Rc7
Doesn't that win the bishop on b5? Or am I just missing something this late at night? |
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Aug-29-21
 | | 0ZeR0: What a neat puzzle! I probably wouldn’t have found it had WGM Yiyi Xiao not been player of the day. |
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Kibitzing
sac: 21.Rxc3