| May-06-13 | | luzhin: The rapid progress of White's QN from c3 to c8(!) is a cavalry assault to remember. |
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May-06-13
 | | SteinitzLives: I always think black playing g5 in the Sicilian despite not castling risks overplaying ones' hand. I like Robsons' mini-knights-tour is oool, thanks for mentioning it. |
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Feb-12-15
 | | Phony Benoni: With pieces hanging on both sides, desperado tactics can be considered and you always like the knight's chances in such situations. The first thing I looked at was the fork on f6, but neither g8 or d5 seemed effective Get-There-From-Here squares.
Well,
can we do something on d6 instead? 31.Nf5 doesn't seem likely, but 31.Nc8, protected by the rook is another matter. And a quick glance doesn't reveal any effective counter for Black. |
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Feb-12-15
 | | al wazir: I found 31. Nc8, but didn't see black's reply 31...Qf3. Part credit. |
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| Feb-12-15 | | patzer2: The setup for the winning move in this game is a trap set with 30. Nxe7!? (diagram below).
click for larger viewBlack falls into the trap with 30...Bxf1 and allows White to play the winning 31. Nc8!!  , which is today's Thursday puzzle solution. Here's my analysis with Fritz 12:
<30. Nxe7!?> This sets a trap for Black. Objectively better for White is 30. Nc7+ Kd7 31. Rfe1  . <30... Bxf1?> This falls into the trap and loses the game. Instead, Black can hold with 30... Kxe7! 31. Rfe1 Qd5 = to  . <31. Nc8!!> This move saves the piece and wins the game. <31...Qf3>
If 31... Kd7, then 32. Nb6+ .
<32. Nxd6+ Kd7 33. Qb6! Rfc8> Forced due to the mate threat (e.g. 33... Bb5 34. Qc7#). <34. Nxc8> This wins easily. Fritz prefers to complicate for a stronger evaluation with 34. Nc5+ Ke7 (34... Rxc5 35. Rxc5 Ke7 36. Qc7+ Kf8 37. Rxe5 ) 35. Bb4 Rc6 36. Qxb7+ Kf8 37. Qxa8+ Kg7 38. Bc3 . <34... Rxc8 35. Qd4+> Black resigns in lieu of 35...Qd5 (35...Ke7 36. Bb4+ Rc5 37. Qxc5+ Kd7 38. Qc8#) 36. Qxd5+ exd5 37. Rxf1 . |
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| Feb-12-15 | | agb2002: White has a knight for a rook and two pawns.
Black threatens Kxe7 and to place the bishop on a safe square. The position of Black's king and queen suggests 31.Nc8, avoiding Kxe7 and threatening both 32.Nxd6+ and 32.Qxf1: A) 31... Kd8 32.Qf6+ and 33.Qe7#.
B) 31... Kd7 32.Nb6+
B.1) 32... Ke8 33.Nxa8 + - [N vs 2P] and the double threat 34.Q(R)xf1 and 34.Rc8+ with mate in two. B.2) 32... Kd8(e7) 33.Qf6+ Ke8 34.Nxa8 as in B.1.
C) 31... Nc4 32.Rxc4 and both 32... B(Q)xc4 lose to 33.Nxd6+. D) 31... Qd5 32.Nb6 looks winning. For example, 32... Qd3 33.Nxa8 Bh3 34.Rc8+ Kd7 35.Nb6+ Ke7 36.Qf6#. E) 31... Rxc8 32.Rxc8+ Ke7 33.Qf6+ Kd7 34.Rxf8 + - [R vs 2P]. |
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| Feb-12-15 | | diagonalley: i rate this one as very hard... <diagonalley>: nul points :-( |
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| Feb-12-15 | | Nick46: <diagonalley:> Yep, made up for yesterday's easy peasy. |
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| Feb-12-15 | | morfishine: I finally arrived at <31.Nc8> after eliminating all other tries. The threat 32.Nxd6+ forking the Queen, is too much for Black to handle. I just don't see a good move for Black ***** |
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| Feb-12-15 | | gofer: It looks like position is pretty even, black may be an exchange and two pawns up, but white has all the activity! There are so many choices and some rely on move order, so I think I will go with the most forcing... <31 Nc8 ...>
White threatens Nxd6+
Refusing the sacrifice seems to lose quite quickly and spectacularly... 31 ... Nd3
32 Nxd6+ Kd7 (Ke7 Qf6+ )
33 Qb6
31 ... Ng4
32 Nxd6+ Ke7/Kd7
33 Qb6
31 ... Qf3
32 Nxd6+ Kd7 (Ke7 Qc5 )
33 Qb6
31 ... Kd7
32 Nxd6 Kxd6
33 Qc5+ Kd7
34 Bb4 ...
35 ... Nc6
35 Qd6+ Kc8 (Ke8 Rxc6 )
36 Ba5
35 ... Qc6
36 Qe7+ Kc8
37 Qxf8+ Kc7 (Kd7 38 Qe7+ Kc8 39 Bd6 mating)
38 Qd6+ Kb6 (Kc8 Ba5 )
39 Bc5+ Kb4
40 Nd4+
<31 ... Rxc8>
<32 Rxc8+ ...>
32 ... Ke7
33 Qf6+ Kd7
34 Rxf8
32 ... Kd7
33 Rxf8
In either case White is a whole rook up, but can still defend
his king against any back rank mate threats...
~~~
Yep, but I didn't think the following line had any chance
of success, and perhaps I should have given it more thought... 31 ... Qf3
32 Nxd6+ Kd7 (Ke7 Qc5 )
33 Qb6 |
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| Feb-12-15 | | et1: from yesterday to today, from easy to difficult |
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| Feb-12-15 | | TheBish: Robson vs M Arnold, 2013 White to play (31.?) "Medium"
Black is ahead an Exchange and two pawns, while both sides have a piece en prise. 31. Nc8! threatens Nxd6+, winning the queen, while maintaining the threat on the bishop on f1. (a) 31...Nd3 32. Qf6! threatens mate and forces 32...Rxc8 33. Rxc8+ Kd7 34. Rxf8 with mate soon to follow. (b) 31...Nc4 32. Rxc4! renews the threat and continues the attack. (c) 31...Qd3 32. Qf6 Ng6 33. Rc7! and Black has no good answer to the threat of 34. Re7+ Kd8 35. Rxf7+ Kxc8 36. Rxf8+ Nxf8 37. Qxf8+ Kc7 38. Qxa8, leaving White a piece ahead. (d) 31...Qf3 32. Nxd6+ Kd7 (or 32...Ke7 33. Qc5) 33. Qb6 and White's attack is crushing, e.g. 33...Rac8 34. Nxc8 Rxc8 35. Qd4+ Ke7 36. Rxc8 leaves White up a rook. |
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| Feb-12-15 | | TheaN: Thursday 12 February 2015 <31.?> For whatever reason it took me a long time to see this, although the idea of the move is the most logical in this position. White is down an exchange and two pawns, and black is threatening to win the Ne7. In compensation white got the open c-file, a centralized black king and an outpost on f6. In terms of piece activity black is not even doing that bad, although his rooks are more defenders than offenders in the current position. In this puzzle, the stamp 'puzzle' made it harder for me: I looked at crazy ideas at first: trying to trap the black queen with Re1, invading directly at the black king with Qb6 (futile as b7 is defended), throwing knights for tempos with Nc5, even Ng6 and Nc6. However, the simplest question is: "can we safe the piece currently in trouble?". Answering that question gives white the only move that can keep the material unbalance slightly levelled and threaten forks at the same time. <31.Nc8> is the only move protecting the knight, Δ Nxd6+: A) Capturing <31....Rxc8? 32.Rxc8+ Kd7 (Ke7 33.Qf6+ Kd7 34.Rxf8 ) 33.Rxf8 > will cost black at least two rooks for the knight, so the knight is immune. B) Counterattacking via d3 <31....Nd3? 32.Qf6! > and black's only defense against Δ Qe7# & Nxd6+ is 32....Rxc8, which doesn't fair much better than variation A. C) Defending on d5 <31....Qd5?! 32.Qf6 Ng6 (Nc6? 33.Rxc6! ) 33.Nxb6 > essentially costs black a tempo compared to the next variation as this forks queen and rook. D) Defending on d3 <31....Qd3> might be the most tricky defense, but because black now abandons b7, suddenly <32.Qb6!> is very strong. Essentially Δ 32.Nd6+ with 33.Rc7+ and this is hard to defend. If 32....Nc4? 33.Rxc4! Qxc4 34.Nxd6+ , 32....Nc6? 33.Rxc6! bxc6 34.Qxc6+ Kd8 35.Ba5# 1-0. Instead <32....Rxc8 33.Rxc8+ Ke7 34.Qxb7+ Nd7 35.Rxf8 Kxf8 36.Qxd7 > and the entire back rank got sweeped away. E) Attacking the queen <31....Qe2 32.Qb6> does not change much from variation D, in the sense that black only has the potential spite check Qd1+ when the rook moves, but with the black rooks and knight off the board, white can safely interpose Bc1 if this happens. I'm not sure if white creates enough after 32.Rxf1 Qxf2 33.Rxf2, although it looks winning. |
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| Feb-12-15 | | TheaN: 31....Qf3 seems black's best defense, given it defends b7, blocks the f-file and threatens to trade queen. 32.Nxd6+ apparantly works, meaning it could be played after my 31....Qe2 as well. I had the idea of Qb6 though, so I do think I'll take credit for this one: after 31....Qf3 32.Nxd6+ is the only logical move, bringing in the queen next. |
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Feb-12-15
 | | Penguincw: Just a wild calculation with flaws: 31.Rxf1 Kxe7 32.Qf6+ Ke8? 33.g6 Nd7?? 34.gxf7+ Rxf7 35.Qxf7+ Kd8 36.Qg8+ Kc7 37.Qxa8, and in this variation, white is completely winning. I considered 30.Nc8, but couldn't find any followup. |
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Feb-12-15
 | | offramp: I didn't see this one at all at all. |
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| Feb-12-15 | | Cheapo by the Dozen: I didn't see Qb6. I would have played Nc8 anyway, because I did see a line to gain a piece and equalize material. So maybe I would have wound up getting it right over the board. :) |
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| Feb-12-15 | | CHESSTTCAMPS: White has a material disadvantage of a knight for a rook plus two pawns. Both sides have a minor piece en prise (Ne7 and Bf1), a typical desperado scenario. The key to the puzzle is observing that white's knight has only one protected escape square, and the rest falls into place: 31.Nc8!
Gains a tempo by threatening the royal fork at d6, making it impossible for black to avoid major loss of material. A) 31... Rxc8 32.Rxc8+ Ke7 (Kd7 33.Rxf8) 33.Qf6+ Kd7 34.Rxf8 leaves white up a rook for 2 pawns and black has no play against the white king. B) 31... Nd3 32.Qf6! (a 2nd tempo gaining desperado) Rxc8 (forced) 33.Rxc8+ Kd7 34.Rxf8 is similar to A. C) 31... Kd7 32.Nb6+ Kd8|e7 33.Qf6+ Ke8 34.Nxa8 Bc4 (to prevent Rc8+ followed by Nb6#) 35.Na5! d5 36.b3 and black must lose more material to avoid mate. D) 31... Kd8? 32.Qf6+ Kd7 33.Qe7#
E) 31... B moves? 32.Nxd6+ wins.
F) 31... Qg6 32.Qb6! Bc4 (Rxc8 33.Rxc8+ mates next) 33.Nxd6+ Kd7 (Ke7 34.Qc7+ Nd7 35.Rxc4) 34.Nc5+ Ke7 35.Qc7+ Nd7 36.Qxd7# Time for review.... |
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| Feb-12-15 | | CHESSTTCAMPS: Missed the game defense (31...Qf3), which maintains protection of b7. |
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Feb-12-15
 | | gawain: Like some others I saw 31 Nc8 but was not ready for the reply (the game continuation) 31...Qf3. Perhaps over the board I would have found the winning follow-up 32 Nxd6+ Kd7 33 Qb6. (And perhaps not!) |
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Feb-12-15
 | | chrisowen: All bets are off shape a c8 regiment a line,
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tat oh rat a tat tat a boon and oh bush over
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at his door a fan dangle flap for fast in flavor and favor fawn bishop queen affix ignores a cut i curry to brown off ive in the bag a spot b6 and bang believe black in e8 |
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| Feb-12-15 | | BOSTER: <luzhin: The rapid progress of White's QN from c3 to c8...>. As <patzer2 with Fritz12 wrote after 30.Nxe7 Kxe7> Black is better. And here he is right.
So,<Robson's mini-knight tour> should be and could be interrupted. |
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Feb-12-15
 | | Jimfromprovidence: In the line 31 Nc8 Kd7 32 Nb6+ Ke8 33 Nxa8, I thought about 33...Bc4 as a possibly good defense.
click for larger viewBut it looks like white has 34 Na5 followed by 35 Nb6 and I cannot find a way for black to retain his bishop. |
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Kibitzing
sac: 30.Nxe7