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|Feb-18-08|| ||newzild: Rxg6 seems the easiest way to secure the draw. Easy, but cute.|
|Feb-18-08|| ||TheaN: 1/1
70....Rxg6 = as 71.fxg6 stalemate and Philidor's position otherwise.
|Feb-18-08|| ||JohnBoy: <Random: 15...Bxf3 16.Qxf3 Qxh2+ > I am not sure that I agree with the computer evaluation. How does black capitalize on the pawn-plus? White has just made a clever gambit (if not clearly entirely intentional) to open the h file. There are two bishops pointing at the black king, and the black queen will get pushed around as white pulls heavy artillery into position. Isn't this essentially what happened? Can anyone suggest why (aside from the pawn) this is given a evaluation after move 16?|
|Feb-18-08|| ||whiteshark: 70...Rxg6 was easy, but white could play on, e.g. 71.Rf7 or Rh1 to check black's endgame knowledge.|
|Feb-18-08|| ||notyetagm: <johnlspouge: Monday (Very Easy): Black to play and draw |
Material: Black is down 2Ps. The Black Kg8 has no legal move.
Candidates (70...): Rxg6
70...Rxg6 fxg6 stalemate
The only alternative is a drawn R+P vs R endgame, because the Black Kg8 is not cut off from f8. The general plan for Black is to check from the side, until the P advances to the 6-th rank, and then check from behind. The White K can not escape the checks without abandoning the P. The draw can be confirmed from the Nalimov tables at
Very informative post.
So check from the side until the pawn advances to the 6th rank, and then check from behind a la <Philidor> since the White 6th-rank pawn denies the White king a shelter to hide from the rear checks of the Black rook.
|Feb-18-08|| ||zb2cr: 70. ... Rxg6 is the only way to secure the draw. Very easy indeed.|
|Feb-18-08|| ||geezerbloke: straight forward enough but obviously helps when you know what youre looking for.|
|Feb-18-08|| ||notyetagm: <zb2cr: 70. ... Rxg6 is the only way to secure the draw. Very easy indeed.>|
Not -that- easy because the actual player of the Black pieces -resigned- this position, overlooking the fact that he has a <DESPERADO ROOK> because White's last move (70 d7-e7?) just <STALEMATED> his Black g8-king.
Again, it's easy in this context because -you- know that it's a Monday puzzle at chessgames.com.
|Feb-18-08|| ||megnetz: This puzzle indeed requires some endgame knowledge.|
|Feb-18-08|| ||notyetagm: <megnetz: This puzzle indeed requires some endgame knowledge.>|
It was not obvious to me that the endgame was drawn after 70 ... a6xg6! if White refrains from capturing the Black g6-rook (71 f5xg6 <stalemate>), due to the active position of both the White e7-king and 7th-rank White h7-rook.
Regardless, 70 ... a6xg6! is still the strongest move because even if you do not see that the resulting endgame is a draw, at least you have won a critical pawn and have much greater drawing chances than before.
|Feb-18-08|| ||notyetagm: <TheaN: 1/1
70....Rxg6 = as 71.fxg6 stalemate and Philidor's position otherwise.>
I am simply amazed that the <PHILIDOR METHOD> works with the White king and rook advanced so far up the board: they are both on the 7th rank!
Position after 70 ... a6xg6! 1/2-1/2
click for larger view
And the point is that the <PHILIDOR METHOD> draws even here(!) because the Black g8-king is -not- cutoff from the f8-promotion square, as someone pointed out earlier.
Boy, this Monday puzzle has taught me alot about the endgame.
|Feb-18-08|| ||namke: Maybe I´m blind but whats on -70.Ra7+ 71. Kf6 Rxh7 72.gxh7 and white wins!?
(-71. Ra6+ 72Kg5 wins I think.|
|Feb-18-08|| ||tarek1: May not be very easy to find, but once you found, very easy to check. There are only two variations, both very simple.|
|Feb-18-08|| ||notyetagm: There are now two games in my Game Collection: Rook endings and in each one a player gives away 1/2-point because of failure to see the saving resource of the <PHILIDOR METHOD>. So instead of scoring 1/2, the weaker side scored 0/2.|
And shockingly, one of those players was super-GM Michael Adams (in a blitz game) in Adams vs Dreev, 2007!!!
|Feb-18-08|| ||johnlspouge: <notyetagm>, I should add one thing to my sketch of the draw strategy. In a drawn ending R+P vs. R, the superior R can interpose to defend its K. The inferior side can (and should) arrange that the exchange of Rs leads to a drawn ending K+P vs. K.|
<<noctiferus>: This is a Nalimov's win: white in 27 moves.>
My version of the Nalimov tables disagrees. Make sure you enter the position after 70...Rxg6.
|Feb-18-08|| ||notyetagm: <johnlspouge: win: ... My version of the Nalimov tables disagrees. Make sure you enter the position after 70...Rxg6.>|
Yes, that's probably an "off by one" error", as we say in the computer field.
One of you probably has the position after 70 d7-e7?, the other has the position after 70 ... a6xg6!.
|Feb-18-08|| ||Magic Castle: Its a draw even if white does not take the rook with 71. Rf7 Ra6 72. Rf8+Kh7. Now any move by white except Rf7+, black simply checks the white King from the a file. Once the king attacks the black rook by going to the B file the rook transfers to the E file effectively confining the King out of the action. Then the battle is confined to a position where the white Rook is at f8 and his pawn at f6, with black king at h7. Now you can apply the Philidor method. Once the pawn is moved. The black king simply attacks the pawn and the rook. If rook checks, the King only attacks the rook and pawn and the pawn falls because of the double attack on the pawn by black king and rook. If the rook gets out of the F file. Black rook just takes the pawn. So either way this is a draw.|
|Feb-18-08|| ||noctiferus: <johnlspouge>
Sorry for the misunderstanding: my fault. I was looking at 65..., where white still wins (:
I was analysing Rybka's, Fritz's, toga's anomalous scores at 65..., due to first repetiton, that many engine evaluate as draw to avoid two-fold repetition
|Feb-18-08|| ||znprdx: Black was 1st= at Strasbourg the same year ...I don't buy that a GM (rated 2596 in mid seventies) would miss this resource for a stalemate. Knowing he had a draw...he (or his opponent) may have been very short on time and was probably looking for a way to swindle a win [!?)
Plachetka vs N Mamedov, 2007
As for White: This is as bad as it gets – 2 connected passed pawns and unable to win – it is enough to make you want to give up tournament Chess – I did.... I couldn’t stand playing against opponents who didn’t know when to resign :)
|Feb-18-08|| ||znprdx: (69.Plachetka to play vs.Mamedov 2007) |
click for larger view
|Feb-18-08|| ||johnlspouge: <<notyetagm> wrote: <johnlspouge> [snip] Very informative post.>|
Thanks. The most hideous thing about my post, I just realized, is that I read the basic idea of winning the R+P vs. R ending (i.e., the Lucena position) more than 30 years ago, and I still retained it. No wonder I am such a bore at parties...
|Feb-18-08|| ||vibes43: A good puzzle for me. Due to a change in my work schedule, I don't often have opportunity to solve these early-week puzzles.|
|Feb-18-08|| ||The beginner: The white rook is on the wrong side of the king, had it been on the Queenside instead b7, c7, d7 then it should be lucena position. where white can build the "bridge" Ie at some point he can stop the checks by moving his rook in front of the king. |
The position in the puzzle is called philidor. Where black he can keep checking white and white he can not leave his pawn and go for the rook, because when he does black will simply capture the pawn.
|Feb-18-08|| ||Fezzik: No way in the world is this just a 1-star position. The basic Philidor position is beyond many players' abilities, and this is not basic after 70...Rg6! Rh4!|
In fact, we reach positions that are difficult to analyse even for GMs! (see Korchnoi's "Practical Rook Endings" or Levenfish and Smyslov's "Rook Endings" to see just how difficult this position is.)
Ok, Black shouldn't have resigned, and the best move is fairly obvious. But after that, the game is very difficult!
|Feb-18-08|| ||zb2cr: Hi <notyetagm>,
You wrote: "Again, it's easy in this context because -you- know that it's a Monday puzzle at chessgames.com."
Okay, correction accepted. I have to confess my first thought on seeing this puzzle with Black to move was: "Aha! This must be a stalemate swindle, there's no way this could be a win for Black." This focused my mental energies on seeing the swindle.
Yet it's also true that I am not in Plachetka's shoes at the time of this game. I have not been playing for several hours; I'm not physically and mentally tired from the long game; above all, I haven't had the crushing mental burden of of being down by 2 Pawns for the last 10 moves. I think this last factor may have been the worst. When you know that, fatally, inevitably, by being down by two Pawns, you are going to LOSE, it mentally sets you up in a state of hopelessness, and you may not see an unexpected drawing resource.
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