theory is one thing, practice is another. The game concluded thus:- 69 … Ne6 70. Ke3 Ke5 71. Kd3 Kf4 72. Kc3 Ke3 73. Kb2 Nd4 74. Ka2 Kd3 75. Kb2 Kc4 76. Ka3 Kb5 77. Kb2 Kb4 78. Ka2 Kc4 79. Kb1 Kd3 80. Ka2 Kc3 81. Kb1 Ne2 82. Ka2 Kb4 83. Kb2 Nd4 84. Kc1 Kc3 85. Kb1 Ne2 86. Ka2 Nc1 + 87. Kb1 Nb3 88. Ka2 Nd2 89. Ka3 Nb3 90. Ka2 Nd4 91. Kb1 Ne2 This in fact is a threefold repetition but I did not notice it at the time – it is immaterial since by this point IM Welling had decided to throw in the towel and this move was preparatory to an elegant draw offer made via the capture on h5. 92. Ka2 Nf4 93. Kb1 Nxh5 draw agreed. After the game Welling told me that in his original analysis of 9. Nxf7 he had eventually concluded that Black stood better after 12 … Kd7, which would explain why he was happy to go into the line,‘ but clearly that assessment’ s a load of rubbish!’ he added with a smile. And from my perspective, thanks to IM Lane for taking a more optimistic view of Welling’ s invention than the man did himself – as he puts it.[ 4 ] The ending after 9 … Bxd1 underlines the significance of White’ s superior development.
~~~~~~
For the record, Ennis lost the match 4.5 to 1.5 – a fighting performance, with IM Petr Neuman and Rory Quinn also drawing on boards 1 and 4 respectively. But let’ s return to the position after 68 … Nxg7. This brings us into the arcane realm of Troitzky Endgames, named for Russian analyst A. A. Troitzky – a world I never knew existed until penning this write-up. Before looking at Troitzky’ s ideas in more detail, let’ s return to the problem facing IM Welling after move 68 – and lest we were to conclude that Welling failed just because he is‘ only’ an IM, my Ennis colleague IM Petr Neuman told me that strong GM V. Babula had had a similar position against him not long ago and couldn’ t do it either – we can quickly discern some general principles that illustrate why it is so difficult to bring home the win:- 1. Black has to be confident he can calculate the mating solution before moving the blockading Knight in for the kill since as soon as he does so he is committed. 2. Black has to take into account what will happen after the pawn queens. If this move delivers check or attacks the mating piece, then the win has gone. 3. It is hard to steer the enemy King just using King and Knight. From point 2 above, we can deduce that depending on which file the remaining pawn is on, the solution differs. This leads us to the concept of the Troitzky Line.
����������� ����������� �����������
����������� ����������� �����������
����������� ����������� �����������
�����������
If the pawn is blockaded on or before this line then the attacker will win on best play. If the pawn is blockaded after this line then the board can be divided into two zones – a winning zone and a drawing zone – and the defending King, if not confined by the opponent, should aim to get to the drawing zone to secure the half point. This is not the complete story however. Some of the Troitzky wins take more than 50 moves on best play – the longest is 115 moves! If we were to create a 50 move Troitzky line it would look like this:
����������� ����������� ����������� ����������� ����������� ����������� ����������� ����������� ����������� ����������
Apparently a win can also be achieved in 50 moves or under with a pawn blockaded on b2 / b3 or g2 / g3 in about 99 % of instances. For the present game I’ ll begin by exploring a few ideas worked out with my colleague Rory Quinn on the way back from Ohrid during a lengthy flight delay at Budapest airport, that give a flavour of what is involved. We set up a checkmate with the defending king on a1, then working backwards we found that one solution for the game begins with the following starting position:
����������� ����������� ����������� �����������
����������� ����������� �����������
����������� ����������� �����������
The Knight could equally well be on d3 as e2. Checkmate can then be delivered thus 1. Ka1 Nc1 2. Kb1 Na2 3. Ka1 Nf5 4. h6 Nd4 5. h7 Nc3 6. h8 = Q Nc2 # Well this is just dandy if the White King cooperates by sitting on a1, but what if instead of a pawn move White plays at some point Kb1? Can Black apply corrective action to his plan in mid flow? In a word yes, eg; 5. Kb1 Ne2 6. h7 Nac3 + 7. Ka1 Nd4 8. h8 = Q Nc2 #. The King move at other points
26 | P a g e I r i s h C h e s s J o u r n a l