< Earlier Kibitzing · PAGE 1 OF 3 ·
|Sep-27-09|| ||OBIT: OK, after about 30 minutes of study, it seems clear Black is playing for a draw, and a bishops of opposite color endgame seems to be the best way to try for it. So, my move would be 36. Rxc7, but I'm sure the puzzle wants me to present more analysis than that. And, I have to admit, it's certainly not clear what Black has to do to secure the draw. He is only a pawn down, normally not a fatal material deficit in an opposite-colored bishop ending, but in this particular case, where White has connected passed pawns in the center, the one pawn advantage looks like it could easily be decisive.
Is there a way for Black to blockade those center pawns? This answer is going to be instructive... sorry, but I just gotta peek...|
|Sep-27-09|| ||Athamas: Black is down a pawn and is looking to draw in a rook and bishop ending. White has extraordinarily strong passed pawns on the d and e files. Black only seems to have 2 real moves. Either Kf7 or Rxc7. My first instinct for some reason is Rxc7, Bxc7 b4... I'm not sure why. You lose another pawn and don't seem to have much compensation... perhaps the tempo to put the king in front of the pawns. I would be pretty tempted to play Kf7 in a game, but looking at the move, it seems to lose pretty badly. There's no way to stop white's king from pushing the connected passed pawns. So it must be the most odd rook exchange.|
36...Rxc7 37. Bxc7
My instinct tells me to push the b-pawn but logic tells me it's ridiculous. However, just moving the king ends in the same lost ending as Kf7 initially.
37...b4 38. axb4
King move is still fruitless... perhaps pushing the pawns forward a step will pull them far enough away from the white king.
38...Ba6 39. d4 Bd3 40. e5 Bc4 41. Kf2
Now what? White is threatening to centralize the king and push the pawns. Black's king cannot intervene fast enough, which only leaves the bishop to protect. However, Bd5 immediately allows the b-pawn to win the game.
41...a6 42. Ke3 Bd5
I'm not certain how the game would go from here, but black seems to have a fighting chance for a draw with the bishop neutralizing the central pawns and all of black's pawns off the white bishop's diaganols. More than likely would have just suffered the loss in a real game... just looks like suicide giving up another pawn.
|Sep-27-09|| ||newzild: White has only three candidates: 36...Kf7, 36...Rf7 or 36...Rxc7, as 36...Kf8 loses to 37. Bd6, and 36...Kf6 loses to 37.Bg5+|
Clearly black is aiming for a draw. His goal should be to force the two white centre pawns onto dark squares, so that he can blockade with his king and bishop. Then the opposite-coloured bishop ending is drawn. This much is obvious enough.
Unfortunately, I failed to find the clever suggestion of Alekhine's. I instead tried to find lines that got black's queenside majority rolling, distracting white and giving black time to set up the central blockade. I couldn't find anything concrete - because there was nothing to find.
6/7 this week...
|Sep-27-09|| ||OBIT: Wow, I have to admit, the solution is amazing. Black sacrifices a second pawn so that his bishop can force the White pawns to dark squares, and this allows his king and bishop to set up a blockade on the light squares. So, Black draws despite being two pawns down - great endgame!|
|Sep-27-09|| ||offramp: Alekhine was a great analyst. Many people might have just played through this ending quickly thinking that it was a straightforward win for white all the way. Clearly AAA was checking every move.|
|Sep-27-09|| ||SimonWebbsTiger: "Sadly" I already knew the answer. Mind you, it does give me an excuse to offer a bit of advice for young players who wish to improve their game: buy well annotated games collections (be they of a player or a tournament/match, e.g. Alekhine's book of the 1924 New York tournament and Alekhine's best games); also, learn endgames. That sort of study will help far more than merely ploughing through openings. :)|
|Sep-27-09|| ||zuddybeek: I think this is an interesting experience. I have missed three puzzles this week but got this one correct? :)|
|Sep-27-09|| ||lost in space: Haven't got it (I was not even near to the solution) |
I was thinking about 36...Rxc7 37. Bxc7. But what next? I was not able to find Aljechin's 37...b4, the key move for the draw and the today's puzzle.
I was also thinking about 36...Kf7 and 36..Rf7, the only alternatives to Rxc7. Also here I found no clear way how to get the draw.
Hoping for Monday.
|Sep-27-09|| ||remolino: Did not find b4... I should have since the exchange of rooks is required for Black, and the main problem to solve it how to defend with oppossite color bihops, e.g., how to set a blockade.|
|Sep-27-09|| ||An Englishman: Good Evening: <zuddybeek>, I can "top" that (or perhaps "bottom" is correct?), for I missed Wednesday through Saturday, and got this one correct. When I claim that a Sunday puzzle must be too easy because I solved it, I know whereof I write.|
|Sep-27-09|| ||DoubleCheck: Ok so at position (36...?) I have a couple but important candidate moves|
Both seem 'appropriate' but only one will help the move order!
First, lets try Rxc7
37. Bxc7 Kf6
38. Kf2 g4
39. Ke3 h5
40. g3 h4
41. gxh4 gxh4
Variation at 40. g3 -> 40. d4
40. d4 Ke6
41. Bb8 a6
42. h3 g4
43. Bf4 Bc8
44. gxh4 gxh4
45. Kd3 Bd7
Its seem white has decisive-advantage but looks like dead-draw
Ok now the other move: 36...Kf7
(of course not 36...Kf6?? 37.Bg5+! and 36... Kf8?? 37. Bd6!)
37. Rc5! a6
I think retaining the rooks provides winning chances for both players
38. Kf2 Rd7!? Black rook needs to find a target
and now im stuck because
39... h5 allows 40. Bg5+ a commanding post for the bishop
39... Ke6 > 40. Re5+ Kf6 41. Rc5 (Not 40...Kd6?? 41. Rxb5+!)
and position repeated
39... Ba8? 40. Rc8 -> Rf8-h8 or even just 40. d4!
I think I have missed something, the position is drawish with opposite coloured bishops but the white center passed-pawns give him the edge
lets have a look now
37. Bxc7 b4!
Oh well I missed 37... b4! but I guess I can take something in that Lasker a world champion also missed it!
|Sep-27-09|| ||dzechiel: Black to move (36...?). White is up a pawn. Insane.|
Wow. I wanted to play 36...Kf7 as well. This has not been one of my better weeks.
|Sep-27-09|| ||beatgiant: What happens after 36...Rxc7 37. Bxc7 b4 <38. Kf2> bxa3 39. Be5+? Material is equal, but Black's pawns are easily stopped while White's connected passers look very dangerous.|
|Sep-27-09|| ||RandomVisitor: Opening up my Basic Chess Endings (Fine, Benko, 2003) to page 195 we have this, concerning bishops of opposite color and pawn endings:|
"it is evident that when one side has two connected passed pawns, unblocked, his opponent will have to give up his bishop to stop them."
and this, page 203:
"We have repreatedly emphasized that mobility is the decisive factor in all phases of chess. Nowhere is this more clearly demonstrated than in endings with bishpos of opposite colors. At times the defender can draw when he is two pawns down because his opponent's pawns are blocked. And with weak pawns the defender can lose when material is even."
You <do> have a copy of Basic Chess Endings, don't you?
|Sep-27-09|| ||goodevans: I'm going to award myself full marks today. Not because I saw the whole thing (I saw the line in the annotation only as far as move 40), but on the criterion "what would you play in this position OTB".|
A good week for me. It might even have been 7/7 but I missed a day out earlier in the week.
|Sep-27-09|| ||Biscoito: @DoubleCheck: I believe you might be confusing Edward Lasker for Emanuel Lasker.|
|Sep-27-09|| ||gofer: Black is a pawn down and white controls the centre. There are no stalemate options and black
must either protect the rook with Rf7, Kf8, Kf7, Kf6 or play Rxc7.|
Now I find it difficult to see how any of these options are going to stop white from winning.
36 ... Kf6 37 Bg5+ loses immediately
36 ... Kf8 37 Bd6 loses immediately
36 ... Rxc7 38 Bxc7 seems to be losing as the black "a" pawn can't go anywhere and white is controlling the centre...
36 ... Rf7 37 Rxf7+ Kxf7 38 Bc7 seems to be losing as the black "a" pawn can't go anywhere and white is controlling the centre...
36 ... Kf7 37 Rxe7+ Kxe7 38 Bc7 seems to be losing as the black "a" pawn can't go anywhere and white is controlling the centre...
I think this last variation is slightly better for black as at least the king is closer to his a and b pawns and so there is the possibility of causing mischief or at least slow down black's progress, but I can't see any win. I think this is simply a case of getting a draw at best!
36 ... Kf7
37 Rxe7+ Kxe7
38 Bc7 Kd7
39 Ba5 Kc6
40 Kf2 Kc5
41 Ke3 Bc8
now maybe black can draw???!!! The LSB bishop can probably slow down the two central pawns and the king can start to push the a an b pawns ... ... I am probably way out, but...
Time to check...
|Sep-27-09|| ||gofer: Nice to see that I thought exactly like Mr. Lasker... |
...pity that I would have lost in exactly the same way!
|Sep-27-09|| ||OhioChessFan: Intuition only gets you so far. Clearly, 36....Rxc7 was a necessity or Black gets steamrolled. But 37...b4 is so anti-intuitive there's no way I'd have found it. What would the thought process be? "I'm down a Pawn, he has connected passers in the middle. Why don't I give up another Pawn?"|
|Sep-27-09|| ||OhioChessFan: I'm not sure about AA's claim that 36. Kf2 was "now necessary". 36. Rc5 is fine, with 37. Kf2 following up or not.|
|Sep-27-09|| ||OhioChessFan: <What happens after 36...Rxc7 37. Bxc7 b4 <38. Kf2> bxa3 39. Be5+? Material is equal, but Black's pawns are easily stopped while White's connected passers look very dangerous. >|
<BeatGiant> That's an interesting line. 39...Kf7 for sure. That leaves this position:
click for larger view
The White King can get to e3 and support the d Pawn so that Black can't play the effective Ba6/d3/c4 maneuver. But if the King is there, he can't support the g and h Pawns when they are pushed. Meanwhile, after an eventual a2, White's DSB can't leave the a1 diagonal. c3 seems like a good spot there to keep the Black King at bay. Maybe the Black King can hold the fort, but it does seem like it leaves a few more winning options than the game continuation.
|Sep-27-09|| ||johnlspouge: Sunday (Insane):
Bogoljubov vs Ed Lasker, 1924 (36...?)
Black to play and draw.
Material: Down a P, with Bs of opposite color. The White Kg1 has 3 legal moves and is secured from check. The White Rc7 attacks Bb7 and pins Re7 to Kg7. Black should seek a draw in an endgame with Bs of opposite color.
Candidates (36...): Rxc7
Black needs to force the connected passers onto dark squares, to stop them on light squares.
37…b4 38.axb4 [else, drop a P]
38…Ba3 39.d4 [else, lose the connected passer Pd3]
39…Bd3 40.e5 [else, lose the connected passer Pe4]
40…Bc4 41.b5 [else, Pa6 and White can make no progress]
41…Kf7 42.Bb8 Ke6 43.Bxa7 Bxb5
White can make no progress.
|Sep-27-09|| ||johnlspouge: The key idea is to force the central passers onto dark squares, where they are immobile, so White can make no progress in an endgame of opposite colored Bs.|
|Sep-27-09|| ||5hrsolver: I got 36...Rxc7 37.Bxc7 b4!
It's bishops of opposite colors. I know the theme so it was a little bit easy for me to find.
< johnlspouge: The key idea is to force the central passers onto dark squares, where they are immobile, so White can make no progress in an endgame of opposite colored Bs. >
|Sep-27-09|| ||znsprdx: glad I didn't spend too much time on this - there most have been dozens of continuations. Black to play as a problem I would presume at least was to draw (being a pawn down) |
Actually I found a cute idea that might work OTB (especially in zeitnot): 36...Rx[R]c7 37. Bx[R]c7 Ba6!
The idea is to attack the d3-e4 pawns. It assumes that White will respond with 38.d4 which of course is not forced. ...b4 39.axb4 Bd3 40.e5 Kf7
Now in the old days White would seal 41._ -_ _ assuming 41.Kf2 the position now is:
click for larger view
I cannot see black losing this in fact there are even swindle possibilities.
Interesting is ...42.Ke6 43.Ke3 Bf1
I would be grateful if someone would provide some computer feedback
ps. <johnlspouge: The key idea is to force the central passers onto dark squares> it certainly is not to lose ...
What is happening here <CG>?
(... and what are the references to Alekhine?)this has been a very disappointing exercise in futility.
< Earlier Kibitzing · PAGE 1 OF 3 ·