Irish Chess Journal Diciembre 2010 | Page 26

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 .
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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 .
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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 :
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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 :
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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
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