|
< Earlier Kibitzing · PAGE 2 OF 3 ·
Later Kibitzing> |
| Nov-11-10 | | agb2002: The problems of text optimization: line E.2 should say "39.Nxd3 Qxd3 40.Qh7+ + -" instead of "39.Nxd3 is similar to E.1" and this time it is particularly annoying because I saw the skewer when I considered 37... Qf1, but forgot it. |
|
| Nov-11-10 | | ozmikey: Got this one eventually after trying to make 37. Qxf7+ Kxf7 38. Nc6 work for a while (after 38...Ba6 White has nothing). Nice combination. |
|
| Nov-11-10 | | gofer: There are a couple of themes running here...
1) Qc7 is well placed. It protects the b8-h2 diagonal, attacks Qf7 and Pb7. If the queen vacates the b8-h2 diagonal then
there is always the possibility of a statemate.
2) Qc7 is immune. 1 ... Qxc7 2 ... bxc7 and Pc7 will promote as Nd4 is protecting against Bf5. 3) Qf7 and Kg6 are ideally placed to create a royal fork by playing Ne5+, what's worse is that Bd3 is trapped in this too! So the plan is obvious, try to get Nd4 to Ne5. There are two paths for the knight but only one works (37 Nf3 Qxc7 38 bxc7 Bf5!) <37 Nc6! ...>
Now this is nice...
37 ... bxc6 38 Qxf7+ Kxf7 39 b7 winning
37 ... Any bishop or pawn move 38 Ne5+ winning
37 ... Kg7/Kf6 38 Qxf7+ Kxf7 38 Ne5+ winning
So that just leaves Queen moves!
37 ... Qg7/Qh7/Qe8/Qf8/Qg8 38 Ne5+ winning
37 ... Qf4+ 38 Qxf4 gxf4 39 Ne5+ winning
37 ... Qxc7 38 bxc7 Bf5 39 Ne7+ winning
37 ... Qf5 38 Ne7+ winning
So black cannot protect Pb7 and Bd3, so given the choice, I think black will forget Pb7, protect Bd3
and try to get a counter attack going at some point by playing Be4. Main Line
<37 ... Qf1>
But now the fun really starts!
<38 Ne5+! ...> not to win the bishop but the trap the king! 38 ... Kh5 39 g4+ Kh5 40 Ng6+ Bxg6 41 Qg3#!
38 ... Kf5 39 Nxd3! winning the bishop as Qh7+ is available <38 ... Kf6> (forced) <39 Ng4+! ...>
Suddenly black's position is crumbling! The queen and knight combo are going to have a "field-day" ripping black's pawns apart. As long as we remember about the caveat of point 1) above! The black king cannot escape up the board (39 ... Kf5 40 Ne3+!) and so is
stuck in the open where the checks are going to come thick and fast and
white is going to take all the pawns it can or trap the king in the corner, either way I would love to be white! 39 ... Kg6 40 Qd6+
39 ... Ke6 40 Qe5+
Now I could go on forever with this one, as it is far from over, but its time to check... |
|
| Nov-11-10 | | kirchhoff: Normaly I don't get Thursday puzzles, but this time I saw the triple fork on e5 and couldn't find a way for black to deal with it, so Nc6 seemed to be the best move. |
|
| Nov-11-10 | | turbo231: I'm running behind again I just played yesterday's ""medium easy puzzle"".
I played Nh5+ against Houdini and got mated. Houdini moved to kg8 and I didn't know what to do. Then I played Houdini against chessgamestv or whatever I guess they use Crafty. Crafty moved to kf8 and it took Houdini 30 moves to finally mate Crafty. So much for ""medium easy"" it's a Saturday's puzzle. |
|
| Nov-11-10 | | gofer: In the following position we have two schools of thought...
click for larger view39 Ng4+ ...
39 Nxd3 ...
Anyone know what is Fritz's choice and which of these two scores more highly? Crafty EGT can let you try both...
http://www.chessvideos.tv/endgame-t... |
|
| Nov-11-10 | | CHESSTTCAMPS: In this ending, white has a knight for a light-squared bishop (LSB) and the most advanced pawn on the board at b6. White's king is perfectly sheltered on h2, while black's king is vulnerable to troublesome checks. Clearly this is about promoting the b-pawn. Black may intend 37... Ba6 to protect the b7-pawn, but white can get there first: 37.Nc6!
A much more potent fork threat than 37.Nf3?, met by Qxc7 38.bxc7 Bf5. There is no defense to all the threats: A) 37... bxc6 38.Qxf7+ Kxf7 39.b7 wins.
B) 37... Qxc7 38.bxc7 Bf5 39.Ne7+ Kf6 40.Nxf5 wins.
C) 37... B moves 38.Ne5+ wins
D) 37... Kg7 (or f6) 38.Qxf7+ Kxf7 39.Ne5+ wins.
E) 37... Qf4+ 38.Qxf4 gxf4 39.Ne5+ wins
F) 37... Qf1 38.Ne5+ Kf6 39.Nxd3 Qxd3 40.Qxb7 Qxc3 41.Qc7 and white promotes the b-pawn, with the white king sheltered from checks. F.1) 38... Kh5 39.g4+ Kh4 40.Ng6#
F.2) 38... Kf5 39.Nxd3 Qxd3 40.Qh7+ wins.
G) 37... Q other 38.Ne5+ followed by 39.Nxd3 wins.
Much easier than yesterday. |
|
| Nov-11-10 | | Stormbringer: I got the first move with a view to eliminating b7, maybe getting a fork or two but didn't understand Black's defence or White's response. To be honest I don't think I even understood the best way to play if bxc6. Was Black going for a perpetual? |
|
| Nov-11-10 | | mrsaturdaypants: 37 Nc6 looked tempting once I saw that both captures lose for black: (a) 37...bxc6 38 Qxf7 Kxf7 39 b7, and promotion.
(b) 37...Qxc7 38 bxc7 Bf5 39 Ne7+, and promotion.
So, what other options does black have? White is threatening a royal knight fork on e5, so black needs to move the queen or king. (c) 37...Qe4+ 38 Qxe4 fxe4 39 Ne5+, winning the bishop. The best I can find is
(d) 37...Kg7 38 Nd8 Qxc7+ Bf5, and white will win black's bishop. Time to check.
(c) 37...Bf5 |
|
| Nov-11-10 | | desiobu: Looking for a good way to bring the knight to e5 is how I stumbled on the solution. |
|
| Nov-11-10 | | CHESSTTCAMPS: I made a couple mistakes that I found by reading <gofer>'s post. F.1) 40.Ng6+ is *not* mate, but 41.Qg3 is!
At the end of line F, it is important to note that 41... d4 should be met by 42.Qd6+ followed by 43.b7. Thanks <gofer> for providing the Crafty link. |
|
| Nov-11-10 | | David2009: D Howell vs N Giffard, 2009 White 37? 37 Nc6 appears to win a Pawn:
A 37...Qf4+ (best) 38 Qxf4 gxf4 39 Ne7+ Kf6 40 Nxd5 Ke5 41 Nb4 Ke4!? 42 g4 fxg3+ 43 Kxg3 Bf5 44 h4 and White a Pawn up should be winning but there is plenty of play in the position;
B 37...bxc6? 38 Qxf7+ 1-0
C 37...Qxc7? 38 bxc7 Bf4 39 Ne7+ 1-0
D 37...Bd4? 38 Ne5+ 1-0 but NOT 38.Qxf7+? Kxf7 39 Ne8+ Kf6 40 Nxb7?
d4! 0-1
E 37...Qf6?! (hoping for Qxb7? Qf4+) 38 Ne5+ wins the Bishop
F 37...Kg7 (to avoid the fork on e5) 38 Qxf7+ and 39 Ne5+ wins the B.
Time to see how things went:
====
37..Qf1 was played protecting the B. After 39...Qxd3 White can safely play 40 Qxb7 etc. with an easy ending since there is no longer a perpetual check. No doubt this is why Black resigned. Time to look at the kibitzes.
====
Not a good day! In my line A, I fail to spot that 39 Ne5+ wins the Bishop. Thanks <VincentL> and <agb2002>. <After 39...Qxd3 White can safely play 40 Qxb7 etc> - <VincentL> has posted the skewer Qh7+ (much better). As <gofer> points out, after 37...Qf1 38 Ne5+ Kh5 (instead of Kf5) walks into a mating net. Crafty End Game Trainer check of the puzzle position:
click for larger view D Howell vs N Giffard, 2009 White 37?
http://www.chessvideos.tv/endgame-t...
Crafty defends with my line F and finds ingenious counter-play a N down, but for once I win first time. |
|
| Nov-11-10 | | madrasvinod: There are three issues here,
1. Pawn close to queening.
2. Knight in a position where it could give forks.
3. Black queen not in a position to give perpetual checks.
Having these three issues in mind the solution was quite easy. |
|
| Nov-11-10 | | Skakalec: <Stormbringer> on bxc6? Qxf7+ Kxf7 and b7 winns easy |
|
| Nov-11-10 | | azax: Thursday puzzle. 37. ? "Medium."
Material: White has a N for B.
Ideas: I think white's best shot right here is to play Ne5+ and hope is opponent doesn't notice it's illegal. ...While that's a bit wishful, the idea is still good: White would like to play Ne5+ . How can his N maneuver there? He has Nd4-f3 or Nd4-c6 as possible routes. Nc6 is more threatening because his N is moved further up the board and is immune to capture due to the b6 pawn. 37. Nc6 should be it. ---
It was probably worth analyzing past move 1, but since Nc6 looks like it wants to be played, I trusted my instinct on this one. |
|
| Nov-11-10 | | Patriot: My initial candidates were Qxf7+, b4?, Nc6, and Nf3. True, I didn't consider Qd6+ which could be a problem. After seeing 37.Nc6, everything started to click because every forcing move proved winning. A) 37...Qxc7 38.bxc7 Bf5 39.Ne7+ followed by 40.Nxf5 and 41.c8=Q B) 37...bxc6 38.Qxf7+ Kxf7 39.b7
C) 37...Qf4+ 38.Qxf4 gxf4 39.Ne5+ and 40.Nxd3
D) 37...Bf5 38.Ne5+ winning the queen and the game.
I saw nothing else forcing and no threats from black so that's where I stopped. But is there anything else forcing? Looking back over my analysis, Qf7 is perhaps another forcing move to consider even though it is easily defeated with 38.Ne5+ and 38.Nxd3. That pretty much does it for forcing moves. But <David2009> helped me realize yesterday that just because all forcing moves by black (in this case) is winning for white it doesn't mean Nc6 is best. That's because black has at least one non-forcing move to stop the knight forks winning the bishop or queen. If any non-forcing replies defeat white's plan of winning material then it is possible there could be a better move besides Nc6. There could be anyway, but it shows that if you have the time to do so, you should try developing a more complete list of candidates before falling in love with a single candidate that looks like it wins or draws from an otherwise losing position. If the non-forcing game move 37...Qf1 prevented black from losing material it may be that Nc6 should be reconsidered and perhaps Nf3 should be examined more closely. <CHESSTTCAMPS> I particularly like your analysis because you considered the forcing replies by black and also considered non-forcing replies that sidestep the knight forks (i.e. king moves, bishop moves, and specifically Qf1). This shows good technique in analysis and is very thorough. |
|
| Nov-11-10 | | David2009: <gofer>, <CHESSTTCAMPS>: Your recent posts arrived whilst I was composing mine (D Howell vs N Giffard, 2009). The line 37 Nc6! Qf1! 37 38.Ne5+ Kf6! is tougher to break down than either 38...Kf5? as in the game or 38...Kh5 39.Nxd3 Qxd3 40.Qf7+ and mates. Let's play the ending out against Crafty EGT starting 38.Ne5+ Kf6:
click for larger view D Howell vs N Giffard, 2009 White 38?
http://www.chessvideos.tv/endgame-t...
Exchanging the Bishop is the natural way to go IMO since we know from endgame theory that Q+Pb7 vs Q is a win if (a) the enemy king is cu off and (b) the White King can shelter from the checks. So we continue 39.Nxd3 Qxd3 40.Qxb7 Qxc3 to reach 
click for larger viewThere is now a cunning quick win starting 41. Qc7! d4 42 Qd8+ Kf5 43.b7 which I leave you to explore. However OTB and my instinctive choice is the slower but thematic win starting 41.Qxd5 Ke7 42.b7 Qc7+. 
click for larger view Howell-Gifford Queen ending variation 42?
http://www.chessvideos.tv/endgame-t...
White now has to escape the checks. This is tricky but can be done in several ways. The most thematic way is with Kg1. Firms time around I messed it up. Second time around I remembered the cross-check strategy one would use in the bare KQP vs KQ ending (i.e. ignoring the King side pawns):
43.Kg1 Qc1+ 44.Kh2 Qf4+ 45.Kg1 Qc1+ 46.Kf2 Qf4+ 47.Ke2 Qc7 48.Kd3 Kf6 49.Qb5 Qg3+ 50.Kc4 Qf4+ 51.Kb3 Qg3+ 52.Ka2 and promotes safely. There are interesting wins starting 43. g3 Qc2+ which I leave you to explore. <gofer>: No disrespect but have you considered putting a title on your Crafty positions when composing them? Otherwise if I want to retrieve a link some weeks later and I see ‘Custom Crafty Position’
my Internet Explorer can’t easily distinguish which is which. |
|
| Nov-11-10 | | patzer2: For today's Thursday solution, 37. Nc6! combines the decoy, clearance, deflection, knight fork and passed pawn tactics to clear the way for the advance and promotion of White's pawn on b6. Playing it out with Fritz, my choice of 37. Nf3  to  also seems to work, but the winning technique is longer and more difficult. Instead, 37. Nc3! is much easier, because in the variation 37...Qxc7+ 38. bxc7 Bf5, White has the Knight fork 39. Ne7+ available to remove the pesky Bishop and quickly clear the way for the pawn on b3 to promote. In the 37. Nf3 line, after 37...Qxc7+ 38. bxc7 Bf5 39. Nd4 Bd7 40. Nb5! White will be able to win the Bishop and has good winning chances in the ensuing Knight versus pawns endgame. But the win is tricky and much more difficult. So, it is much better to play 37. Nc6! where the access to the e7 square for the Knight fork enables White to promote the pawn with an easy win. P.S.: I suppose this puzzle, at least for me, reinforces the advice "if you find a good move, look to see if you can find a better one." |
|
| Nov-11-10 | | gofer: <<gofer>: No disrespect...> Fair point, I suppose I don't think my comments have any longevity, so I don't think about them ever being read in the future. I will try to improve... In passing, Crafty EGT does come unstuck quite quickly... 39 Ng4+ Kg6
40 Qd6+ Kg7
41 Qxh6+ Kf7
42 Ne5+ Ke7
43 Qxg5+ Ke6
44 Nxd3+ Qxd3
45 Qg4+ Kf6
46 Qd4+ winning easily |
|
| Nov-11-10 | | BOSTER: The only promising move for white is 37.Nc6, creating many threats on e5 square, even royal fork.
Black can not take on c7 ,playing 37...Qxc7 38.bxc7 and if 38...Bf5 39.Ne7+ with win.
Black can not take the bold knight, playing 37...bxc6 because of 38.Qxf7+ Kxf7 39.b7.
Black can not play 37...Qf4+ with drawish hope, because of 38.Qxf4 gxf4 39.Ne5+ and then Nxd3. The more defensive line is 37....Kf6(orKg7) 38.Qxf7+ Kxf7 39.Nd8+ Ke7 40.Nxb7 d4 41.xd4 Be4 42.Nc5 Bc6 and white,nevertheless, wins.
This is not coincidence that in this position white knight on d4 (this is called "centralisation") has such great possibilities.
Explanation is very easy- all black pieces and pawns b7,d5 are on the ame color. |
|
| Nov-11-10 | | Patriot: <BOSTER> <The more defensive line is 37....Kf6(orKg7) 38.Qxf7+ Kxf7 39.Nd8+ Ke7 40.Nxb7 d4 41.xd4 Be4 42.Nc5 Bc6 and white,nevertheless, wins.> Much easier is 37...Kf6/Kg7 38.Qxf7+ Kxf7 39.Ne5+ followed by 40.Nxd3. |
|
Nov-11-10
 | | Jimfromprovidence: 36....Kg8, below, seems to take away all of white's threats, unlike the disastrous 36...Kg6??
click for larger view |
|
| Nov-11-10 | | mig55: After 37../Kf6 38. Qxq/KxQ 39. Nd8 works also... |
|
| Nov-11-10 | | wals: Went for the inferior move Nf3.
depth: 19 : 6 min :
White error
(=0.11):9.Ne5. Best, 0.00,  0.52.
depth: 22 : 5 min :
Black blunder
(+2.00):35...Qf7. Best, Kf6, 0.59.
depth: 22 : 6 min :
Black blunder
(+8.95):36...Kg6. Best, Kg8, +2.20.
h5, +2.30.
Black's woes continued,
37...Qf1, +13.91. Best, bxc6, +8.95.
38...Kf5, +14.79. Best, Kf6, +13.91.
until resignation move 39. |
|
| Nov-11-10 | | BOSTER: <Patriot> <Much easier is 38 . Qxf7+ Kxf7 39.Ne5+>
You are right.But I had the great desire to promote "b" pawn. |
|
 |
|
|
< Earlier Kibitzing · PAGE 2 OF 3 ·
Later Kibitzing> |
Kibitzing
