Aug-09-16
 | | Phony Benoni: Pin and Fork, with a bit of a twist. |
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| Aug-09-16 | | plumbst: The first move has to be 27.Re8! threatening Qg7#. After the forced 27...Qxe8 28.Nf6 Rg7 29.Nxe8 White should win easily. |
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Aug-09-16
 | | Penguincw: What's worse than missing a Monday puzzle? Missing a Monday and Tuesday puzzle. I hope to avoid that fate. Well, I did not get it right away, but several ideas came to me: mate on g7, taking on h7, knight check on f6, rook to e8, and a rook lift. Eventually, I was able to use these ideas to find the solution. 27.Re8 was played. If 27...Rxe8, then obviously 28.Qg7# 1-0. If black plays a "useless" move such as 28...Bd7, then 29.Qg7# 1-0 (pin). Of course, black can also play 28...Qf6, but that just runs into 29.Nxf6 Nf8 30.Rxf8 Rxf8 and pick your favourite mate. 28.Nf6 is a nice move, forking 2 pieces, and the h7 mate square. The move played in the game was 28...Qe3+, which I did not anticipate, but the response 29.Qxe3 looks pretty obvious and straight forward to me. At this point, white has a queen vs. rook and bishop, so some work still has to be done. Other than 28...Qe3+, the other 2 ways black can delay mate are 28...Nf8 (then just 29.Nxe8, similar situation as 28...Qe3+) and 28...Rg7. If 28...Rg7, e8 says there's actually a mate coming up: 29.Nxe8 Rg8 30.Nf6 Rg7 31.Nh5 Rg8 32.Qg5 Re8 33.Qf6+ Kg8 34.Qg7# 1-0. Not the easiest Tuesday puzzle ever, but I'm glad I got at least most of it. |
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| Aug-09-16 | | saturn2: Got it. At the beginning of the combination black has more material. But after Re8 black has to give thr queen. for example. 27...QxR 28 Nf6 Rg7 29 NxQ and now white has more material. |
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| Aug-09-16 | | YuvalKenoll: Why not 28 d5? |
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| Aug-09-16 | | YuvalKenoll: Correction: 27 d5 |
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| Aug-09-16 | | alshatranji: "YuvalKenoll: Why not 28 d5?"
28... Qc5+, then Qf8. |
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| Aug-09-16 | | alshatranji: More surprising than Korchnoi losing to this simple tactic is that he continued to play so long after losing his queen. |
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| Aug-09-16 | | WorstPlayerEver: Gotta love Korchy for his fighting spirit; any of the modern patzers would have resigned after such a bust. Except Crawlsen perhaps: he loves to play on his opponents mistakes. Read: sleepiness. |
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| Aug-09-16 | | agb2002: White is a bishop down.
Black's threatens to consolidate with Bd7 or Be6. Another threat is 27... Nh4 28.Qxc6 The rook on g8 stops Qg7# and the black queen prevents Nf6, a move which would fork e8 and h7. These details lead to 27.Re8: A) 27... Qxe8 28.Nf6
A.1) 28... Qf8 29.Qxh7#.
A.2) 28... Qe3+ 29.Qxe3 + - [Q vs R+B] and attack. For example, 29... Rd8 30.Qh6 Nf8 31.Nh5 Ne6 32.d5 Rxd5 33.Nf6 Nf8 34.Qxf8#. A.3) 28... Rg7 29.Nxe8 Rg8 30.Nf6 Rg7 31.d5 + - [Q vs R+B] with ideas like Re1, d6, d7, etc. A.4) 28... Nf8 29.Nxe8 is similar to the above lines. B) 27... Nf8 28.Nf6 (threatens 29.Rxf8; losing are 28.Rxf8 Qxh6 - + and 28.Qxf8 Qxe8 - +; unclear is 28.Qxc6 bxc6 29.Nf6 Bb7 30.Rxa8 Bxa8 31.Nxg8 Kxg8 32.Rb1 Nd7 [R vs B+N]) B.1) 28... Rg7 29.Rxf8+ Rg8 30.Qxh7#.
B.2) 28... Qxf6 29.Qxf6+ Rg7 30.Rxf8#.
B.3) 28... Bd7 29.Rxf8 Ra(g)xf8 (29... Qxf6 30.Qxf6#) 30.Qxh7#. C) 27... Rxe8 28.Qg7#. |
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| Aug-09-16 | | Cheapo by the Dozen: I love Tuesdays!
And it's always cool when one tine of a knight fork points at a threat rather than an actual piece. |
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| Aug-09-16 | | morfishine: Korchnoi seems to have forgot he has a LSB
***** |
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| Aug-09-16 | | dfcx: I was going to play 27.d5? but did not see the black response
27...Qb6+/Qc5+ followed by 28...Bd7.
27.Re8 is the best move. |
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Aug-09-16
 | | Sally Simpson: Nice game...Very Good.
Hi alshatranji.
"More surprising than Korchnoi losing to this simple tactic..." This simple tactic began 6 moves earlier at move 20... 
click for larger view...when White played 20.Bf6.
We then get treated to the instructive joys of a Queen and Knight attack, which White has to see, setting up the final simple tactic. White stuttered slightly he could have played 20.Bxc4 first then 21.Bf6. Here White, checking his lines, realised the c4 Knight has to go. 
click for larger view22.Bxc4 to which Korchnoi could have avoided a disaster with 22...f4 giving the bit back. Probably not an eventual loss but a disaster featuring on POTD. (relegating the winning variation to a 'Why did Korchnoi not play 22...dxc4" question in the thread.) Does Bxc4 matter, the Black Knight seems too far away to help. Let's see. Here is the actual game postion.
click for larger viewYes 1.Re1 Qxe1 2.Nf6 works and wins.
Now look at what happens in Bxc4 had not been played. 
click for larger view1. Re8 Qxe8 2.Nf6 Qe3+
click for larger viewArghhhhhhhhh!!!!! |
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Aug-09-16
 | | gawain: Solved this pretty quickly. 27 Re8 threatens mate in two, and Black cannot capture the rook. 27...Rxe8 allows mate, but 27...Qxe8 loses the queen to the knight fork 28 Nf6. |
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| Aug-09-16 | | YetAnotherAmateur: 27. Re8 is the most forcing move on the board, so that seems like the right place to start. A) 27. ... Rxe8?? 28. Qg7#
B) 27. ... Qxe8 28. Nf6 Qe3+ (other moves lose immediately to Qxh7#) 29. Qxe3  C) 27. ... Bd7/Be6 28. Rxa8 (Rxa8?? 29. Qg7#)
D) 27. ... Nf8 28. Nf6
---D1) Rg7 29. Rxf8+ Rg8 30. Qxh7#
---D2) Qxf6 29. Qxf6+ Rg7 30. Rxf8#
E) 27. ... Ne7 28. Nf6
---E1) Rg7 29. Rxf8+ Rg8 30. Qxh7#
---E2) Qxf6 29. Qxf6+ Rg7 30. Rxf8#
F) 27. ... Qf6 28. Rxg8+ Kxg8 29. Nxf6+ Kh8 30. Qxh7# G) 27. ... other moves 28. Rxg8+ Kxg8 29. Qg7# |
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| Aug-09-16 | | whiteshark: It took me a while to realise sqe8 isn't covered sufficiently. |
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| Aug-09-16 | | King Harvest: <cheapo by the dozen>"...one tine of a knife fork"-- nicely put!
I liked the little tactic that closed the game:
I thought white would play 37.Nh5 (threatening Qg7#) eventually winning at least the N on h4 for free, but Prusikin correctly saw he could just take this poor old simple russian grandfather's N for free right away because black cannot retake on f6: 37.Rxh4 Rxf6 38.Rh6+ Kxh6+ 39.Qxf6+... 40.Qxd8
(*RIP Viktor Korchnoi, greatest grumpy old chessplayer of all time.*)
(And jeez I wish Chessgames allowed editing of posted posts the way the rest of the interwebs do.) |
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| Aug-09-16 | | kevin86: The key is a sac from two directions! The black queen will soon be gone and the king later. |
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| Aug-09-16 | | YouRang: Tuesday 27.?
click for larger view
Often, puzzles are solved by asking: "What piece is stopping my great attack?", and then finding some way to deflect the obstructing piece. Today, the answer to that question has a couple answers: 1. The Rg8 is stopping Qg7#
2. The Q is stopping Nf6 with either Qxh7# or Re8+ to follow. And in this case, we can deflect either piece with <27.Re8!>.
click for larger view
Black can take the rook two ways, but both are bad:
1. 27...Rxe8? 28.Qg7#
2. 27...Qxe8 28.Nf6 forks Q and h7 (threat Qxh7#). Black has to give up the queen to stave off mate (even giving check fails: 28...Qe3 29.Qxe3). Black's other choice is to block my rook and guard h7 with <27...Nf8>
click for larger view
But by vacating g6, this N move allows my Q to guard f6, allowing <28.Nf6>, and black still has to surrender the Q to hold back Rxf8 and Qxh7# (note that 28...Rg6 29.Qxh7# thanks to pin on Nf8). |
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| Aug-09-16 | | drollere: black is ahead a piece, but has doubled pawns and an undeveloped Qside R and B; for the sacrifice white has command of more space and the open K file. this kind of position normally appears when white has found a chink in black's opening and exploited it with a sacrifice to deny black a developing tempo. clearly, if white could displace the R at g8 he would get a cookie. however, the Q guards the R landing square at e8. also, e8 doesn't matter if we could get the N to f6, which is also guarded by the Q. so we have to displace either R or Q. the Q is not going to stop guarding the two critical squares unless we force it to, which means direct threat of mate. Nf6 would do it, but we need the N to mate. so: 27. Re8 Qxe8 (otherwise Rxg8, Kxg8, Qg7#)
28. Nf6 Rg7 (otherwise Qxh7#)
29. Nxe8 Rg8
this isn't quite mate but white can probably work it out from here. clever korchnoi! i missed black's 28. ... Qe3+ disrupting the attack. so i only got 2 moves deep: 5/6 so far this week. |
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Aug-09-16
 | | Fusilli: <YouRang: ... Often, puzzles are solved by asking: "What piece is stopping my great attack?", and then finding some way to deflect the obstructing piece.> Good logic, <YouRang>. |
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| Aug-09-16 | | ruzon: So many puzzles are set up by Black's LSB remaining firmly on c8. |
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Feb-11-25
 | | plang: This opening transposed to a Samisch Nimzo Indian (it is not a Queens Gambit). 8..Qa5?! had been seen a few times previously but seems of questionable value. 12..h6 had been played in the draw I.Sokolov-Inkiov Saltsjobaden 1987-8 (game not included in this database); 12..Re8 was new. An indication of how shaky Black's position was is shown by the variation 17..Nce7 18 Bh6!..gxh 19 Qd2..Kh8 21 Qxh6..Rg8 21 Nf6 winning for White. One idea behind 17..Rf8 was to respond to f4 with ..f5. 18..Na5?! worked out poorly; 18..Bd7 would have been better though White would still have had a powerful initiative. Prusikin considered the best defense to be 19..f5 but after but after 20 g4!..h6 21 Bxf5..Bxf5 22 gxf..hxg 23 fxg..Qd6 24 h4..gxh 25 f4..Nc4 26 f5..Rae8 27 f6 White would still have had a winning initiative. 21..Kh8 22 Qh6..Rg8 23 Re8 ends the game quickly. Another pretty variation is 24..h6 25 Nh5+..Kh7 26 Qf6..Rg8 27 Qg7+!..Rxg7 28 Nf6+..Kh8 29 Re8+. Black resigned due to 37..Rxf6 38 Rh6+..Kxh6 39 Qxf6#. Voted the 5th best game in Informant 94. |
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Kibitzing
sac: 20.Bf6