Normal Topic Endgame of the Week: Zhang-Ni R+P ending. (Read 6843 times)
MNb
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Re: Endgame of the Week: Zhang-Ni R+P ending.
Reply #7 - 07/29/05 at 21:03:15
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The Rg4+/Rh4 idea looks simplest. You are right, that 37...d3 is the last mistake. But White could have played 36.a4 and the Black king is too late.
Thanks for your comments.
  

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Losetowin
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Re: Endgame of the Week: Zhang-Ni R+P ending.
Reply #6 - 07/29/05 at 09:30:11
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I am not convinced that black is lost after the 37th move. if black follow Kevins plan with blockading with king at b7 it looks defencible for example 37.. Kd5 38 a5 Kc5 39 Rb1 Kc6!?  40 Kg3  e3 41 Kf3 Rf7+ 42 Ke2 Kb7 43 Kd3 Ka6 when it looks drawn. Or am i missing a winning plan? The real (last) mistake was 37 ..d3 IMO.

  
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Re: Endgame of the Week: Zhang-Ni R+P ending.
Reply #5 - 07/29/05 at 08:45:04
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A very fascinating endgame.I have looked at the position after move 27 a litle bit and i think if blacks want a draw he can get it easily with  27... f5( nothing wrong with t 32 his i think) 28 Rd3 Ke6 29 a3 Rg4+! 30 Kf2 Rh4 31 Kg3 Rg4+ with a perpetual

My reasoning for this is the following: White king need to protect the weak h-pawn. If he choses to respond to 29 ....Rg4+ with 30 Kh1 his king will be sadly shut out of the game. And if he instead decide to give the h-pawn, black can penetrate behind whites queenside passers. Keeping the rook along the 4rth rank is i think also in spirit of rook endames, where rooks should be used actively. With 29...Rb7 i consider the rook passively placed and infront the the passed pawns.
Thats my theory so far but i will try to look deeper.
  
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MNb
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Re: Endgame of the Week: Zhang-Ni R+P ending.
Reply #4 - 07/27/05 at 22:01:59
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I am afraid it is not as simple, as KevinLudwig stated: 30...Kd5 31.Rb3 Kd6 32.Kf2 Rd7 33.a4 Kc6 34.Rc3+ Kb7 35.b5 Rd6 36.a5 Rd7 37.Ke2 Rd6 38.Rc5 Rd7 39.Rc6 wins. Instead 35...Kb6 (34...Kb6 35.Rc5 is the same) 36.Rc6+ Ka5 37.Ra6+ Kb4 38.b6 looks very good for White too. So maybe 35...d4 is Black's only chance here, though I have my doubts.
On second thought, my idea 30...d5 31.Rb3 e4 32.b5 Ke5 is only a trap: after 33.b6! first d4 fails to 34.Rb5+. And f4 34.exf4+ Kxf4 35.a4 is very similar to the game.
Am I missing something, or has White a won position at move 30?
If I am right, Black should try 27...Ke6 28.Rd3 d5 29.a3 Rb7 30.b4 e4 31.Rb3 Ke5 32.b5 d4. Here KevinLudwig's scheme is risky again: 30...Kd6 31.Rb3 Kc6 32.a4 Rd7 33.Rc3+ Kb7 34.Rc5 d4 35.exd4 exd4 36.Kf2 d3 37.Ke1 Rd4 Rb5+ Ka6 and Black must beware of the weak pawns, though I am not convinced, that he is lost already.
So I prefer to use optimally the Black centralized king. His majesty must be ready both for attack in the centre and defense against the White passed pawns. So my hypothesis is, that 27...f5 is the losing move.
  

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Re: Endgame of the Week: Zhang-Ni R+P ending.
Reply #3 - 07/27/05 at 21:00:23
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Ok, with the game continuation I'm convinced that black is dead lost by the 37th move, no matter what he does. White has blockaded the black passers with the king (ideal blockader) and has his rook behind his own passers, and meanwhile black is stuck blockading white's passers with his rook, and his king will never be able to help his own passers forward. White's plan is simple at that point: just run the a-pawn down the board. As Mnb has pointed out, there is not enough time at that point for the black king to switch places with the rook (if that could be done safely, the position is dead equal).

But, if black knows that is the setup he wants, I think he easily has the draw. For instance:

28. Rd3 Ke6 29. a3 Rb7 30. b4 d5 31. Kf2 Kd6 32. Rb3 Rd7 33. a4 Kc6, and black will continue Kb7, when white will be unable to make progress with his passers, and black is not compelled to undertake anything active with his own central pawns and rook.
  
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Re: Endgame of the Week: Zhang-Ni R+P ending.
Reply #2 - 07/27/05 at 11:39:49
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Awesome. I've been waiting for this week's challenge. I'll check it out when I get home from work tonight!
  
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MNb
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Re: Endgame of the Week: Zhang-Ni R+P ending.
Reply #1 - 07/26/05 at 22:25:28
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Initially I thought 37...Kd5 an improvement, but 38.a5 Kc5 39.Rb1 and there is no defense.
Still 36.a4 might even be more precise.
What about 30...d5 31.Rb3 e4 (I do not believe in d4 shattering the passed pawns) 32.b5 Ke5 33.Kf2 d4 (in stead of f4 transposing to the game) 34.exd4 Kxd4 35.a4 ? I still think White is better, but is there a forced win?
I do not see other defensive ideas for Black. Anyhow, I do not trust computers at all at the 27th move.
  

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Endgame of the Week: Zhang-Ni R+P ending.
07/26/05 at 16:23:57
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Hi all!

This week's endgame comes from China's Sanjin Hotel Cup.  I'm giving the complete game score below, but I want to focus on the pure R+P ending with four pawns each.  White ended up winning by using the a+b passers to great effect.  Fritz considers the position I'm about to give you as slightly favorable for Black!  Is there a defense for Black, or is Fritz just completely misguided here? 

The position occurs after Black's 27th move:

White:  Kg1 Rd1
            Pawns:  a2, b3 e3, h2

Black:  Ke7 Rb4
           Pawns:  d6, e5, f5, h7

White to move.


This ending should be a bit more clear-cut than last week's.  I look forward to seeing your analyses!!!

Zhang Pengxiang (2616) - Ni Hua (2629) [B33]
2nd Sanjin Hotel Cup Tiayuan CHN (5), 13.07.2005



1.e4 c5 2.Nf3 Nc6 3.d4 cxd4 4.Nxd4 Nf6 5.Nc3 e5 6.Ndb5 d6 7.Bg5 a6 8.Na3 b5 9.Nd5 Be7 10.Nxe7 Nxe7 11.Bd3 Bb7 12.Bxf6 gxf6 13.c4 Rg8 14.cxb5 Rxg2 15.bxa6 Bxa6 16.Bxa6 Rxa6 17.Nc4 f5 18.exf5 Nxf5 19.Qd5 Qa8 20.Qxa8+ Rxa8 21.Kf1 Rg4 22.Rg1 Rxg1+ 23.Kxg1 Ra4 24.b3 Rb4 25.Rd1 Ke7 26.Ne3 Nxe3 27.fxe3 f5 28.Rd3 Ke6 29.a3 Rb7 30.b4 e4 31.Rb3 f4 32.exf4 d5 33.Kf2 d4 34.b5 Kf5 35.b6 Kxf4 36.Rb4 Ke5 37.a4 d3 38.Ke3 Kd5 39.a5 Kc6 40.Rb1 Rb8 41.Kxe4 d2 42.Ke3 Rd8 43.Ke2 Kb7 44.Kd1 Ra8 45.Rb5 Ka6 46.Rd5 Rg8 47.h4 Rg2 48.Rd8 h5 49.Rd5 1-0

  
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