Author: Brian Katz
Date: 08:51:20 01/15/04
Go up one level in this thread
On January 15, 2004 at 11:03:05, Igor Gorelikov wrote: >On January 15, 2004 at 10:41:57, Ricardo Gibert wrote: > >>[D]8/1B6/3k3p/pK4p1/P1P3P1/7P/5b2/8 b - - 0 49 >> >>Here is my defensive scheme for Black: >>- White can put his B on any white square he wants >> as Black only needs to use the Black squares. >>- White can leave the Black pawn on a5 or remove it >> from the board at any time he wishes. >>- If White plays K to a-file, Black puts K on c7. >>- If White plays K to b-file, Black puts K on d6. >>- If White plays K to c-file thru h-file, >> Black keeps K on e5. >>- If White plays hxg5, Black answers hxg5. >>- If White plays Pa7 or Pc5, Black captures >> it with his B. >>- The rest of the time Black just temporizes >> with his B on the g1-a7 diagonal. > >What about c4c5 Bxc5 Kxa5 and white's king goes to the h6-pawn which is lost? > >regards >Igor Gorelikov Assuming White has already won Black's a-pawn...... If after that, White has to give up either his a or c pawn he does have anything to fear about losing the h-pawn, because as soon as the h-pawn is taken, Black's Bishop goes to h4 to defend the g-pawn and no more progress can be made on the Kingside. (All Black has to do, is to make sure that his Bishop is on the d1-h4 diagonal when the White King takes the h6 pawn so that he can then go to h4 to defend the g5 pawn.) During that time Black's King just blockades the one remaining White Queenside pawn alternating back and forth while his bishop is still has to defend the g-pawn. Once the White King is no longer attacking the g-pawn while on it's journey back to the Kingside, Black just Blockades the remaining White Queenside pawn and slides his Bishop back and forth on the d1-h4 diagonal preventing the advance of White's h3 pawn. It appears that the only win is if Black incorrectly plays 1...Kc7 which appears to draw, but seems to lose in the end. I will borrow from my other post and paste it here below. There is a lot there. (By the way the Chessbase site game coverage claimed 1...Kc7 a draw, but Michael Steene says he has found a forced win in that variation. Bishop moves like the one mentioned here appear to draw.) Fritz 8, Hiarcs 8 AMD Athlon XP 2600+ choose: > 1.Kc7...which appears to lose in the end, (although both playout the position >differently) >Whereas Crafty 19.08 chooses 1.Bd4...allowing the capture of the a5 pawn with >2.Kxa5 Kc5 3.Bd5 Be5 4.Ka6...and then 4...Bc3 5.a5 Bb4 and the White King cannot >make it to the Queenside without giving back the a-pawn which would then be >drawn. > >This ending sure does APPEAR to be drawn if Black immediately plays 1...Kc7! >driving the White Bishop away and forever controling c7 and then follows with >2...Be1 defending it's a5 pawn....... > >......BUT THIS SEEMS TO BE ONLY AN ILLUSION! AND SEEMS LOST FOR BLACK...... > Perhaps some of you can show a forced win or draw. > >......As White can eventually get it's c-pawn to c6 defended by it's Bishop and >White's King can get to g6 and win the h-6 pawn, but then Black's Bishop goes to >a4 to defend it. Then White shifts his King back to the Queenside to attack the >a5 pawn. Black then has to defend it by placing his Bishop on the e1-a5 >diagonal. >Even if Black times it just right whereas his Bishop gets to e1 to defend the a5 >pawn, when White's King gets to b5 while the c6 pawn is defended by the White >Bishop, White then throws in the pawn sacrifice > 1.h4! gh 2.g5... >and then the pawn advances to g6. Black's Bishop then has to keep and eye on g7 >while White's King is on b5 attacking the a-pawn and his White Bishop is >defending his c6 pawn. Black's King stays on c7. At that point, White makes a >waiting Bishop move while it still defends the c6 pawn and still controlling h1 >to prevent Black from Queening. Black must move it's Bishop from c3( assuming it >was on the ideal square c3 simultaneously defending g7 and the a5 pawn) while >still defending g7 thus allowing the capture of the a5 pawn and WINNING FOR >WHITE! >IF rather than moving the Black Bishop from the ideal c3 square, Black moves his >King to b8 c8 or d8, White's King advances to b6 threatening to advance the pawn >to c7 with check and then it's Bishop to the h3 c8 diagonal checking the King >and the Queening with Check or if the Black King were on c8, it gets hit with >the Bisop Check followed by c7 check and White Queens. If the Black Bishop goes >to e5 to prevent the pawn advance to c7, Black then loses the a5 pawn and loses >the game. > HOWEVER >Some other engines choose to play 1...Be1 first, allowing 2.Kc6 and then the a5 >pawn is eventually lost. But with a Black Bishop on a5 (after taking the a5 >pawn) and Black King on d6, White's King is stuck on the Queenside of the Board. >If somehow White sacs the c-pawn allowing ...Kxc5 the White King can then make >it over to the Kingside and win the h6 pawn but then we get into a position >where Black defends the g-pawn with ...Bh4 and the Bishop stays there as long as >the King is attacking the g-pawn. Meanwhile the Black King stays on a5 or a7 >forever, and no progress is made. Or we can have a position where White >eventually gives up the a-pawn after Black's a-pawn has been captured, and again >we have a drawn position where the Black King controls c5 or c7 forever stopping >White's c-pawn and the Black Bishop again stays on h4 to defend the g-pawn after >White plays Kxh6... > >This is a fascinating position. >1...Kc7 appears to hold the draw, but seems to lose! >and >1...Be1 appears to lose the game, but seems to draw! Perhaps this is why Svidler >resigned. He may have just tossed this variation aside, because he would then be >down 2 pawns. But White has to give one of the Queenside pawns back to get his >King to the Queenside, and this draws. > >At first glance it appears the Black may have a draw with 1...Kc7, but it seems >that White just alternates back and forth combining threats and eventually Black >has to give somewhere. On the other hand, 1...Be1 appears to lose because the a5 >pawn is lost but then Black's King and Bishop combine forces to control the >Black King's access squares to the Kingside, and White then has to sac a KEY >c-pawn to divert the Black King, but this pawn is needed to win the game. > >Grandmasters at that level see into positions like this much faster than you and >I, although they do falter and botch won games and throw away drawn games. In >this case, it appears that Svidler may have been incorrect in his decision. > >Please give your views on this position and correct my views if necessary as >well. >Look forward to hearing from you. >Brian Fritz 8 chooses in Infinite Analysis, the What at first appears to be drawing ...Kc7 but really seems to lose.....BUT chooses the what appears to be DRAWING...Bd4 and other Bishop moves in the Deep Position Analysis Mode. Brian
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