< Earlier Kibitzing · PAGE 3 OF 3 ·
|Feb-04-11|| ||Jimfromprovidence: <Gofer> <What I failed to notice is exactly how strong 43 Be6 is.> |
Excellent post. The difference between 43 Be6 vs. 43 Ba2 (as was discussed earlier) is now white controls d7 and f5 as well as the a2-g8 diagonal after 42 Kh5 Rxe4 43 Be6.
click for larger view
Now, black has no more counterthreats and must give up material, as you described, since 44 g7+ (seeing Rh8+) must be prevented at all costs.
|Feb-04-11|| ||gofer: <VincentL: 42 ... a3>|
White simply ignores the threat of both 43 ... a2 and 43 ... axb3. White has its own threats!
<43 Be6 ...> (threatening 44 g7+ which starts a forced mate in 7)
<43 ... Nxg6>
<44 Kxg6 ...> (now the threat is 45 Kxf6 with 46 Rh8# next, so black must play Rxe4, Rb3 or Ke8)
44 ... Rxe4 45 Kxf6 Rf4+ 46 Bf5 Rxf5+ 47 Kxf5 winning as Pa3 will not promote
44 ... Rb3 45 Kxf6 Rf3+ 46 Bf5 Rxf5+ 47 exf5 winning as Pa3 will not promote
<44 ... Ke8>
<45 Kxf6 Kd8>
click for larger view
Now white can deal with Pa3!
<46 bxa3 Rxe4>
and then go back to the back rank mate threat!
<47 Bd5! Rf4+>
<48 Ke6 ...>
again the king must run away as otherwise the only way to stop mate is to
trade R for B into a losing end game and this give white time to defend its
<48 ... Kc8>
<49 f3 Ra4>
<50 Kxd6 Ra6+>
<51 Bc6 Kb8>
<52 Rh8+ Ka7>
<53 Ra8+ Kb6>
<54 Rxa6+ ...> winning
|Feb-04-11|| ||David2009: Rublevsky vs Ivanchuk, 2008 postscript: I have now caught up with the earlier kibitzes of the regulars, and congratulate everyone who found 42 Kh5! as winning try. It remained to find the win against Crafty End Game Trainer (link in my earlier post as above). The EGT dfends with 38.Nf6 gxf6 39.Rxh6 Rxb4 40.Rh8+ Kg7 41.Rh7+ Kf8 as in the game. Crafty EGT now meets 42.Kh5 with 42...Rxb2 (instead of 42...Rxe4 as analysed by <Phoney Benoni> and others) 43.Kh6 Nxg6 44.Bxg6 a3 45.Rf7+ Ke8 46.Ra7+ Kd8 47.Rxa3 Rxf2 to reach
click for larger view
It took me a long time to win this one. I leave it as a challenge to the interested kibitzers. Crafty EGT link to this position:
|Feb-04-11|| ||doubledrooks: I saw the difficult moves but missed a mate in one!
For example, I noticed 38. Nf6 gxf6 39. Rxh6 Rxb4 40. Rh8+ Kg7 41. Rh7+ Kf8 42. Kh5 Rxe4 43. Be6, reaching the position in <Jimfromprovidence>'s diagram.
I then analyzed 43...Nxg6 44. Kxg6 Re2 45. Kxf6 Rxf2+ 46. Bf5 Ke8, and didn't notice that the mate threat on h8 was still on.
|Feb-04-11|| ||Jimfromprovidence: <david2009> <...The EGT dfends with 38.Nf6 gxf6 39.Rxh6 Rxb4 40.Rh8+ Kg7 41.Rh7+ Kf8 as in the game. Crafty EGT now meets 42.Kh5 with 42...Rxb2 (instead of 42...Rxe4 as analysed by <Phoney Benoni> and others) 43.Kh6 Nxg6 44.Bxg6 a3 45.Rf7+ Ke8 46.Ra7+ Kd8 47.Rxa3 Rxf2 to reach...>|
White still plays 43 Be6 here.
click for larger view
Again the mate threat of 44 g7+ looms large and all of the other threats as well reappear, as described by <gofer> earlier.
|Feb-04-11|| ||Patriot: <Coigach> <Like yesterday, it is clear that W is doing well after playing the initial move (Nf6 here), so OTB trying to analyse deeper at move 38 would not be a great use of time.> |
The big question is, "Does white have anything better?" This move is clearly very strong with two big threats. Realistically, once a move can be proven as best then more calculation is purely a waste of time. Here I wasn't so sure Nf6 is best because things are still in the air with b4 hanging and then b2 and e4. It could turn out that Nf6 looks very good but ends up losing and perhaps Ra1 (going for a draw) is the best way. This doesn't usually happen in puzzles because they are usually biased as having a winning combination, whereas OTB this isn't always the case.
<However, I'm doing these exercises to try and develop my ability to calculate and would like to find the best line at least 4 half moves ahead, and see the main variations within those 4 half moves .>
My instructor, Dan Heisman, recommends looking at least 3-ply starting with your own move. This is a good approach for testing the candidates for their potential--sort of like shopping around for the best buy. This also should help identify moves that are not safe. I think you're on the right track.
<I feel cultivating the ability to calculate short lines accurately may be more valuable for improving chess strength than the capacity to work out lines like 38...Nc6 39.Nd7+ Ke7 40.Nxb8 Nxb8 41.Rxh6 gh 42.Kh5 Kf8 43.Kxh6 Nd7 44.Bd5 Nf6 45.b5. That takes time and effort, and I think kibbitzers who just noted that W will win at least an exchange in that kind of line are taking a more efficient and effective approach to this puzzle.>
I couldn't agree with you more! Dan has said something to the effect that the first move in a variation is the most important because the rest of the game depends on it! That's generally why I like to look wide at candidates before going deeper into any lines. Then I look hard for something that might refute it. Because if after you keep analyzing a particular variation you decide that it's a bad line, then you could find yourself with very little time to find another move and much less time to analyze it. That leads to poor analysis because a player is more likely to play the first best thing they see since the move they spent so much time on doesn't work.
It seems we have a very similar approach and I think it's the most practical.
|Feb-04-11|| ||mworld: <David2009> thanks for that link to the EGT. That challenge is tough indeed. I've given it a dozen blitz tries already and not made it!|
|Feb-04-11|| ||Patriot: <David2009> It took me two tries to win, the first was drawish. After 42...Rxb2 43.Be6 was my choice. Crafty played 43...Nxg6 44.Kxg6 Ke8 45.f3 Rf2 46.Bg4 a3 47.Kxf6 Kd8 48.Ra7 etc. The really big idea to avoid is losing the white pawns, because then the game becomes more drawish.|
|Feb-04-11|| ||mworld: <Patriot: <David2009> It took me two tries to win, the first was drawish. After 42...Rxb2 43.Be6 was my choice. Crafty played 43...Nxg6 44.Kxg6 Ke8 45.f3 Rf2 46.Bg4 a3 47.Kxf6 Kd8 48.Ra7 etc. The really big idea to avoid is losing the white pawns, because then the game becomes more drawish.>|
Patriot: The game above is easy to win from that position and you are correct that the key theme is to keep the pawns and not end up with a rook and bishop versus rook situation where a draw is almost guaranteed.
What David2009 posted was a variation (much tougher one) of this endgame http://www.chessvideos.tv/endgame-t...
|Feb-04-11|| ||Patriot: <David2009> The next time I looked I saw something even better than 48.Ra7 which I'm not sure why this move didn't occur to me the first time: 48.Rd7+ Kc8 49.Rxd6|
<mworld> He posted two positions: the original position and also the tough endgame position that you are referring to.
|Feb-04-11|| ||WhiteRook48: i saw the 38 Nf6|
|Feb-04-11|| ||DarthStapler: I got the first 3 moves|
|Feb-04-11|| ||chrisowen: Dorogatie mellifluously f3 draws h5 a ring loss red er turtle approach in source rb4 sure busk in kg4 can it uphill after.|
|Feb-04-11|| ||chrisowen: 24Nxc5 ie castle Rublevsky re5 main splitting crikey feathers nh5 be7 he restoring parity.|
|Feb-04-11|| ||chrisowen: Flog allo too cork swine plug friday. Knight JD want me for a sunbeam rh6 ow nice nf6 sacrif. It is cob ugly out half 42f3 hand missin kh5 why wasnt it played?|
|Feb-04-11|| ||David2009: <Jim>, <Patriot>: thanks for your comments - as you say, 43 Be6! instead of 43 Kh6 gains that all-important tempo and wins easily.|
<mworld> thanks for giving the second position (in Rublevsky vs Ivanchuk, 2008) a go. Try 48.Ra7
|Feb-04-11|| ||mworld: lol, Ra7 is the start i was just playing before i came to check here. Decided to give it another go. I'm not able to sit and think for long, so I'm sure I'm throwing it away somewhere else now :( |
Oh well, thanks again.
|Feb-04-11|| ||wals: Got 38.Nf6 O.K but not all the following twiddly bits|
Rybka 4 x 64
Black moves that helped White.
d 18 : 8 min :
20...0.0, 0.75. Best,
1. (-0.40): 20...Kd7 21.Qg3 Nh5 22.Qg6 Kc7 23.b4 cxb4 24.cxb4 Rc8 25.Ng5 Bxg5 26.Bxg5 Qf8 27.Bg2 Kb8 28.Rac1 Nf6 29.Bxc6 bxc6 30.Be3 Qg8 31.Qg2 Qd5 32.Qxd5 Nxd5
2. = (-0.04): 20...Nxe4 21.Qg6+ Kd7 22.dxe4 Qg8 23.b3 Rh4 24.Bg2 Kc7 25.Be3 Bf6 26.Rad1 Rd8 27.Re2 Kb8 28.Red2 Qf8 29.a3 Rh8 30.b4 c4 31.Bb6 Rd7
d 21 : 10 min :
23...Nh5, +1.68. Best,
1. (0.81): 23...Nxe4 24.Bxe4 Rfd8 25.Bd5+ Kf8 26.Kg2 Bf6 27.Rh1 Ke8 28.Rh7 Kd7 29.Kg3 Kc7 30.Kg4 Rd7 31.a3 Rf8 32.Be3 b6 33.Rah1 b5 34.Be4 Ne7 35.c4
2. (0.99): 23...Rfe8 24.Ng5 Bd8 25.Bh3 Nd5 26.Be6+ Rxe6 27.Nxe6 Bf6 28.Ng5 Nde7 29.Ne4 Rd8 30.Kf1 Nxg6 31.Ke2 Be7 32.Rg1 Kf7 33.Be3 b6 34.Rg4 d5 35.Ng5+ Bxg5 36.Rxg5
d 20 : 6 min :
27...Bf6, +1.34. Best,
1. (0.65): 27...Rg4 28.Rh1 Ke8 29.Be4 Bf8 30.Raf1 Rd8 31.c4 d5 32.cxd5 Ne7 33.Kh3 Rg5 34.Kh4 Rxg6 35.Bxg6+ Nxg6+ 36.Kg4 Nf4 37.Rh7 Nxd3 38.Nf5 Kf7 39.Ne3
2. (0.78): 27...Bg5 28.Re4 Ke7 29.Rxf4 Bxf4 30.Nf5+ Kd7 31.Nxg7 Ne7 32.Bxb7 Rg8 33.Nh5 Rxg6+ 34.Kf3 d5 35.c4 dxc4 36.Be4 Rb6 37.Nxf4 exf4 38.Rb1 cxd3 39.Bxd3 Rd6 40.Be2 Kc7 41.Rd1 Rb6 42.Rd2 Rf6
d 21 : 7 min :
29...Rxe4, +3.01. Best,
1. (1.32): 29...Bg5 30.Rh1 Bh6 31.Rxf4 exf4 32.Ne4 Rd8 33.Ng5 Bxg5 34.Rh8+ Ng8 35.Rxg8+ Ke7 36.Rxg7 Bf6 37.Rh7 Rh8 38.Bd5+ Rxh7 39.gxh7 b6 40.Kf3 Be5 41.Ke4 Kf8 42.Bb7 Kg7 43.Bxa6 f3 44.d4 cxd4
2. (1.84): 29...Ng8 30.Bxg8 Kxg8 31.Rxf4 exf4 32.Nf5 Re8 33.Nxd6 Re6 34.Nxb7 Be7 35.Na5 Rxg6+ 36.Kf3 Re6 37.Nc4 g5 38.d4 cxd4 39.cxd4 Bd8 40.Ne5 Rd6 41.Ke4 Kg7 42.Rg1 Bf6 43.Rc1 Bxe5 44.Kxe5 Rh6
d 22 : 7 min :
33...a5, +3.33. Best,
1. (1.37): 33...Rb8 34.a3 b4 35.axb4 cxb4 36.c4 a5 37.Ra1 Ra8 38.b3 Ra6 39.Rd1 Rc6 40.Ne2 Nc8 41.Bd5 Rc5 42.Be6 Ne7 43.Rxd6 Nxg6 44.Rd7 Rc6 45.Kf5 a4 46.bxa4 b3 47.Rf7+ Ke8 48.Rb7 Kd8
2. (1.65): 33...Rd8 34.Nh5 d5 35.Nf6 Nxg6 36.Bxg6 Rd6 37.Nh7+ Ke7 38.Kf5 d4 39.cxd4 cxd4 40.Bh5 Bf4 41.Rg1 g5 42.Rf1 g4 43.Kxg4 Rd8 44.Kf3 Rh8 45.Bg6 Rc8 46.Bf5 Rc2 47.Rg1 Rxb2 48.Rg7+ Kd6
d 22 : 8 min :
34...a4, +4.30. Best,
1. (1.61): 34...Rd8 35.Nh5 d5 36.Nf6 Nxg6 37.Bxg6 Rd6 38.Nh7+ Ke7 39.Kf5 dxe4 40.Rh4 Bf4 41.Rg4 b4 42.cxb4 cxb4 43.axb4 axb4 44.Bh5 g5 45.b3 Rd3 46.Rg1 Rxb3 47.Nf6 Kd6 48.Nxe4+ Kc6 49.Nxg5 Bxg5
2. (2.10): 34...Rb8 35.Nh5 Ng8 36.Bxg8
d 22 : 10 :
35...b4, +4.49. Best,
1. (2.29): 35...Ng8 36.Bxg8 Kxg8 37.Rd1 Rf8 38.f3 Rd8 39.Ng3 Kf8 40.Nf5 Rd7 41.Rh1 Kg8 42.Nxh6+ gxh6 43.Rxh6 d5 44.Rh7 Rd6 45.Kf5 dxe4 46.fxe4 Rd2 47.Rc7 c4 48.Kxe5 Rxb2 49.Kd5 Rg2 50.Rb7 Rd2+
2. (2.72): 35...Nxg6 36.Bxg6 Ke7 37.Ng3 Kf6 38.Bh7 Rh8 39.Bf5 Rd8 40.Ne2 Rb8 41.Bd7 Ke7 42.Bc6 Kd8 43.Bd5 Kc7 44.Ng3 Rf8 45.Nf5 c4 46.Kf3 g6 47.Rxh6 gxf5 48.Rh7+ Kb6 49.Rb7+ Ka6 50.exf5 Rxf5+
d 19 : 7 min :
37...Rb8, +4.32. Best,
1. (2.57): 37...Rc8 38.Ra1 Rb8 39.Rxa4 Nc6 40.Bd5 Ne7 41.Ng3 Nxg6 42.Nf5 Ne7 43.Nxd6 g6 44.Ra8 Rxa8 45.Bxa8 Ng8 46.Kf3 Ke7 47.Nc4 Bf4 48.b5 Nf6 49.b6 Kd7 50.Bd5 Kc8 51.Nd6+ Kb8 52.Ke2 g5
2. (3.08): 37...Nxg6 38.Bxg6 Rb8 39.Rd1 Rb6 40.f4 Ke7 41.fxe5 dxe5
|Feb-04-11|| ||wals: Part two
White moves that aided Black.
d 20 : 8 min :
24.Ng3, +0.83. Best,:
1. (1.71): 24.Nxc5 dxc5 25.Bd5+ Kh8 26.Bxc6 bxc6 27.Rxe5 Rf6 28.Rxh5+ Kg8 29.Kf1 Rxg6 30.Be3 Re8 31.Re5 Kf7 32.Re1 Rh8 33.Re4 Ra8 34.b3 a5 35.Ke2 Rh8 36.Ra4 Ra8 37.Rc4 Re6 38.Kd2 Rf6 39.Bf4
d 22 : 4 min :
30.dxe4, +1.24. Best,
1. (3.01): 30.Nxe4 a5 31.Nxd6 Ng8 32.Nxb7 Nh6 33.Bd5 a4 34.Nxc5 Ra5 35.Nd7+ Ke7 36.Nxf6 Kxf6
d 23 : 8 min :
34.a3, +1.70. Best,
1. (3.33): 34.Nf5 Nxf5 35.exf5 Ke7 36.Rxh6 gxh6 37.Bd5 Rc8 38.g7 Kf6 39.g8Q Rxg8+ 40.Bxg8 h5+ 41.Kxh5 Kxf5 42.f3 Kf4 43.Bd5 Ke3 44.Kg6 Kd2 45.Kf6 Kc2 46.Ke6 c4 47.Kxd6 Kxb2 48.Kc5 b4 49.cxb4
2. (2.13): 34.Nh5 Ng8 35.Rd1 Ra6 36.Bxg8 Kxg8 37.Ng3 Bf4
d 23 : 10 min :
35.Nh5, +2.01. Best,
1. (4.30): 35.Nf5 Nxf5 36.exf5
d 21 : 5 min :
36.cxd4, +2.74. Best,
1. (4.49): 36.Nf6 Nxg6 37.Bxg6 b3 38.Nd5 Kg8 39.Ne7+ Kf8 40.Nf5 Rd8 41.Nxh6
d 25 : 6 min :
42.f3, =0.00. Best,
1. (5.34): 42.Kh5 Rxb2 43.Be6 Nxg6 44.Kxg6 Rxf2 45.Bd7
2. (1.22): 42.Be6 Nxg6 43.Kf5 Ne7+ 44.Kxf6 Ng8+ 45.Kg5 Rxe4 46.Rf7+ Ke8 47.Rb7 Re2 48.Bxg8 Rxf2 49.Bd5 Kd8 50.Rb8+ Kc7 51.Rb4 Kd7 52.Kg6 Rd2 53.Rb7+ Kc8 54.Rb5 Rf2 55.Kg5 Rf4 56.Bc6 Kc7 57.Bd5
and Black draws.
|Feb-04-11|| ||OhioChessFan: Pretty straightforward to find Nf6. The themes of removing a defender and clearing a file for a passed Pawn. After the initial attack, White has to be sure to curtail Black's counter attack. Well done by the analysts who have already posted.|
|Feb-04-11|| ||M.Hassan: "Difficult" White to play 38.?
White is a pawn up.
The more I pondered the less I found a winning line and the best I could do is the following line:
Black is forced to take the Knight or else next move Nd7+ and Black is either checkmated or looses the Rook.
and repeat and repeat!
|Feb-05-11|| ||TheBish: Rublevsky vs Ivanchuk, 2008|
I forgot to kibitz before the next problem was posted, but I found the key line, including 42. Kh5! -- I didn't think it was that hard to find, so only give it one exclam!
|Feb-05-11|| ||Phony Benoni: Musing on 42.Kh5:
click for larger view
I'm one who didn't find it, or more accurately didn't appreciate it. I did consider the move, but fixated on a pattern: marching to h6 and forcing mate. It's a classic theme, some famous examples being:
Short vs Timman, 1991;
Teichmann vs Allies, 1902;
Capablanca vs Tartakower, 1924;
Anderssen vs De Riviere, 1859.
But then I saw 42.Kh5 Rxe4 43.Kh6?? Rh4#, decided that 42.Kh5 didn't work, and discarded it.
It would have been a good moment to dream a little. For instance, think about moving the the bishop away, threatening Rxe7 and g7. Of course, if I do that, he can just take the g-pawn. How can I protect it? DING!
At least, that's how I missed it. When 42.Kh5 didn't fit the pattern, I discarded the move from my calculations and didn't realize it had other implications as well. Chess moves rarely do one thing, and one thing only.
|Feb-05-11|| ||OhioChessFan: <PB: But then I saw 42.Kh5 Rxe4 43.Kh6?? Rh4#, decided that 42.Kh5 didn't work, and discarded it.>|
I spent most my time dealing with that. And I almost gave up when I found the above.
|Feb-05-11|| ||David2009: <mworld> Re your post Rublevsky vs Ivanchuk, 2008 Starting from |
click for larger view
a winning sequence aainst Crafty EGT is 48.Ra7 d5 49.exd5 Rd2 50.Bf7 e4 51.Kg6 e3 52.Kxf6. Now if Black plays e2 Re7 wins, so instead the EGT plays 52...Rf2+ 53.Ke6 e2 54.Kd6 Kc8 55.Re7 Rxf7 56.Re8+ Kb7 57.Rxe2 and wins. Link: http://www.chessvideos.tv/endgame-t...
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