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Subject: Re: Tried it again but this time Both choose ...Kc7 Why is that?

Author: Brian Katz

Date: 04:51:02 01/15/04

Go up one level in this thread


On January 15, 2004 at 07:46:08, Brian Katz wrote:

>On January 15, 2004 at 07:33:34, Brian Katz wrote:
>
>>On January 15, 2004 at 06:24:21, Brian Katz wrote:
>>
>>>On January 15, 2004 at 01:45:45, Ricardo Gibert wrote:
>>>
>>>>On January 15, 2004 at 00:19:10, Chesster Fritz wrote:
>>>>
>>>>>On January 14, 2004 at 22:57:32, Sally Weltrop wrote:
>>>>>
>>>>>>[d]8/1B6/3k3p/pK4p1/P1P3P1/7P/5b2/8 b - - 0 49
>>>>>>
>>>>>>Svidler resigns!!!
>>>>>>
>>>>>>Looks like a draw to me and other engines that I have used.
>>>>>
>>>>>Yes it appears to be drawn, but I'm not so sure about that.
>>>>>Computers will be of little help solving this ending imo.
>>>>>
>>>>>White, even though there are Bishops of opposite colour, has an advanced passed
>>>>>pawn, and though it can't Queen, may be Black's undoing, caution at every turn
>>>>>must be used not to lose on the King-Side. With a very deep analysis, it may be
>>>>>a complex win for White. I wouldn't resign so quickly, but I'd be very troubled
>>>>>by this position if I were Black.
>>>>>
>>>>>Maybe this will turn up as a brilliant endgame study in the future.
>>>>>I'm interested on what both Kramnik and Svidler have to say about this game.
>>>>
>>>>White's advantage is purely optical in nature. It's a stone cold draw.
>>>>
>>>>>
>>>>>It's late here, but I may take a stab at it myself, albiet I doubt I'll come up
>>>>>with a definitive answer.
>>>>>
>>>>>This ending takes the highest level of technique, and I'm not Capablanca or
>>>>>Svidler!;-)
>>>>>
>>>>>Most likely we'll see some good analysis from these Grandmasters, (Not
>>>>>Capablanca) unhappily deceased;-), but from Kramnik, Svidler, and other GMs.
>>>>>
>>>>>Fritz
>>>
>>>
>>>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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