|Aug-12-04|| ||Poulsen: A rare endgame in practical chess - but worth studying. Nice work by Bobotsov. |
|Aug-20-04|| ||Chessical: After a huge struggle Bohatirchuk errs with <99..Kb7>, he had to play the K to a7 to continue his resistance. After the move played, Bobotsov plays very accurately:|
<106.Kd7> wins by 106...Ka7 107.Kc7 Ka8 108.Nd5 Ka7 109.Nc3 e3 110.Nb5+ Ka8 111.Nd7 e2 112.Nb6#
|Nov-24-04|| ||fasting: just after looking the game through I can only find of one word for it - madness - that endgame is probably so precise, that I don't get one half of the knight moves... |
|Nov-24-04|| ||Resignation Trap: Here are two other games with two Knights versus a Pawn : Smyslov vs Lilienthal, 1940 and G M Norman vs Lilienthal, 1934 .
I remember these games primarily because Lilienthal was in both of them, and in both games he failed to find the win. |
|Nov-25-04|| ||IMlday: The opening is equally weird. Fedor moves the N/b8 6 times in the first 14 moves. Young Duncan Suttles was just learning the moves. Young Bulgarian Bobotsov would be top-ten in the late 60's. He shows his perseverence in this game.
Dr. Bohatirchuk was another 'amateur'
with chess as a hobby. He gave papers at the radiologist's convention and then relaxed, especially with postal competion, before going back to 'work' in health and medicine.
|Nov-30-04|| ||Ernesto7: i thougth two Knigths couldn't mate?? |
|Nov-30-04|| ||acirce: <Ernesto7> That's right, but two knights against pawn can do that sometimes! Check <Chessical>'s line:|
106...Ka7 107.Kc7 Ka8 108.Nd5 Ka7 109.Nc3 e3 110.Nb5+ Ka8 111.Nd7 e2 112.Nb6#
Without Black's remaining pawn it would have been stalemate after 111.Nd7, and that is what makes the difference.
|Jan-15-05|| ||aw1988: 99...Ka7! draws. |
|Jan-15-05|| ||beatgiant: <aw1988: 99...Ka7! draws.>
Are you sure, and if so could you give the reason?
As far as I understand, the theoretical evaluation of these versus endings is completely determined by how far ahead the Black pawn is when it is blockaded. So it shouldn't change whether there's a mate or not, only how many moves it takes. Of course, that could be significant because of the 50-move rule.
I checked Nalimov tablebase, and it said 99...Ka7 leads to mate in 24 while 99...Kb7 allows mate in only 13. The last pawn move was on move 76, so move 124 would still be barely within the 50-move rule.
|Jan-15-05|| ||aw1988: Would you care to try and demonstrate a win for white? |
|Jan-15-05|| ||beatgiant: <aw1988: Would you care to try and demonstrate a win for white?>|
Excellent challenge, but 24 moves is a bit beyond my own human search horizon. I'm citing a result claimed in Nalimov tablebase.
I checked the Nalimov server at http://www.lokasoft.nl/uk/tbweb.htm. The claimed win begins with 99...Ka7 100. Kc7 Ka6 101. Kc6 and goes on for 22 more moves, with multiple branches.
|Jan-15-05|| ||aw1988: Ok, we can start from there. 99...Ka7 100. Kc7 Ka6 101. Kc6 Ka5. |
|Jan-16-05|| ||beatgiant: <aw1988: Ok, we can start from there.>|
It's pretty time-consuming and would generate 44 more posts as in <beatgiant: 102. Nbd5> <aw1988: 102...Ka4> <beatgiant: 103. Nbd5> etc., so I'm not going to demonstrate the win on the forum.
Instead, I'll give two pointers to check the source: http://en.wikipedia.org/wiki/Forsyt...
explains the FEN notation used by the Nalimov server, and http://www.lokasoft.nl/uk/tbweb.htm is the Nalimov server itself.
To use the Nalimov server, enter the FEN string for the position after 99...Ka7 100. Kc7 Ka6 101. Kc6 Ka5, which is 8/8/1NK5/k7/4p3/4N3/8/8/ w - - 0 0
The server outputs a list of each move with its outcome, with the strongest move first: Nb6-d5 M22, meaning White mates in 22.
You then continue the line with 102. Nbd5, make a reply for Black that you think is interesting, and enter the FEN string for the new position. Do that 22 more times, and you have the demonstration of the win.
|Jan-16-05|| ||aw1988: True enough. I'll test it out shortly. I don't know why I thought we could make a million posts on this page. |
|Jan-16-05|| ||Pawsome: <As far as I understand, the theoretical evaluation of these versus endings is completely determined by how far ahead the Black pawn is when it is blockaded. So it shouldn't change whether there's a mate or not, only how many moves it takes.>
The key to determining whether the ending can be won by the side with the Knights is something called the "Troitzky Line" named after the endgame study composer> It's described in the link below:
Hope this information is of some help.
|Jan-16-05|| ||Willem Wallekers: In 1977 Jan Hein Donner wrote an article on the research he did on this endgame.
He drew two conclusions:
1. In the Troitzky line the pawns b6 en g6 really belong on b5 and g5.
2. When the pawn is on the line or behind it, it's a win for white in all cases, but if the the pawn is further advanced it's still a win in many cases.
|Jan-17-05|| ||Pawsome: Clicking on http://www.google.ca/search?hl=en&a... will take you to part one of "The Damned Pawn" a superb article by Karsten Muller that explores the mechanics of N vs. P endings. The second part of the article, which deals with the second "Troitzky line. The second article can be found in the Chess Cafe article. I Googled it by typing "Troitzky line into the search field. |
|Jun-29-05|| ||Knight13: KNN vs KP endgame, huh. Rather rare. This would be a great game for endgame study!|
Yet I don't understand 54... Ne7.
|Jun-29-05|| ||Resignation Trap: <Knight13> 64...Ne7 was played to eliminate White's last Pawn. In practice, this is Black's best chance!|
|Jun-29-05|| ||Knight13: <Resignation Trap: <Knight13> 64...Ne7 was played to eliminate White's last Pawn. In practice, this is Black's best chance!> Thanks! |
65. Nxe7 is forced or eles it would be draw.
|Oct-30-06|| ||gauer: Does anybody know whether there are any chessbase software extensions out there that make labels for corresponding squares or for sketching the Troitzky line boundaries, given a random positioning of the king(s) or other pieces in each of the smaller piece endings? For instance, chessbase has a "position search" function that allows piece maneuvers to be searched for at random, and I have also heard of Chess Query language. But I haven't found a way to try and see when it can report a winnable Q+PvQ ending or when a R+PvR ending is a draw, other than relying on a mere numerical eval. Is there a method to draw the maneuvering line which one should take as a method of attack, rather than simply rely on a computer eval of #38? For instance, when I purchased the 6-man ending tablebase, I thought that this strategical feature would be automatically implemented in.|
|Mar-18-07|| ||Mendrys: After ....Ka7 107. Kc7 Ka8 108. Nd5 Ka7 109. Nb6 we have:|
click for larger view
this would be stalemate of course if there were no pawn but black is forced to move his pawn twice more while white sets up the mate 109....e3 110. Nc8 Ka8
111. Nd7 e2 112. Ndb6#
|Mar-18-07|| ||aazqua: 45 h5?? Why? Why give the bad bishop new life and create a passed pawnwhere one could not have existed?|
|Jul-25-08|| ||4tmac: Blacks 99 was not best and his 88 was even worse but overall both players did pretty well especially white from move 100 on. Many of these moves were counterintuitive but white played near perfect at the end.|
|Feb-16-10|| ||Check It Out: incredible
this endgame is beyond me