Author: Jorge Pichard
Date: 06:31:05 03/19/03
Go up one level in this thread
On March 19, 2003 at 07:11:50, Ricardo Gibert wrote: >On March 18, 2003 at 15:47:53, Jorge Pichard wrote: > >>This is a very difficult position for most chess programs. >> >>[D]8/8/6k1/2p1p3/2P1P1K1/3N4/8/b7 w - - 0 1 >> >>This position was given by Pachman in the third volume of his "Complete >>Chess Strategy" trilogy to illustrate a position where a computer >>would have great difficulty finding the right idea. In fairness, >>it might be added that most humans would fail this particular test; >>indeed in the game Pachman grabbed the pawn. 1.Kxc5? >> >>This obvious, materialistic move throws away the win' "White's >>c-pawn cannot be advanced to the queening square without the help of >>the king, but this allows Black to counter by attacking the e-pawn"- >>Pachman. >> >> >>Supposing it were instead Black to move, the following variation is >>enlightening: >> >>1... Bd4 2. Ne1 Bf2 3. Nf3 Kf6 or 3...Bd4 4. Kh4+ Kf6 5. Kf5 >>4. Kh5 Bg3 5. Nh4 Bf2 6. Nf5 Bg1 7. Nh6 Bd4 8. Ng4+ Ke6 9. Kg6 >> >>[D]8/8/4k1K1/2p1p3/2PbP1N1/8/8/8 b - - 0 9 >> >>White will now play Kf6-h7-g5+, etc and win easily. However, > > >Did Pachman say, "White will now play Nf6-h7-g5+, etc and win easily" or is this >what you say? If this is what Pachman said, then it is clear he did not fully >understand the position, because I'm a NM who can't find the win. Pachman didn't say anything at all, it was IM Graham Burgess who said that Pachman missed an opportunity to win, since Pachman himself grabbed the c pawn and the game ended in a draw. But IM Burgess on his book stated that this would be a great position for programs since they are too materialists and eventually will grab the pawn like Pachman did back in 1944. It was IM Burgess who stated "White will now play Nf6-h7-g5+, etc and win easily" so I tested most of my programs and noticed that all grabbed the c pawn just like Pachman did. Pichard >It seems Black gets just enough counterplay by making an appropriately timed run >around to attack the pawns from the rear via a5 with his King. It is very >possible that Pachman assumed this type of defence was not possible. > >The endgame ability of even GMs is often greatly exagerated in the minds of most >players. This is largely due to the examination of games from the days where >players benefitted greatly from adjournment analysis. > >If you can dig up evidence the position can be won following Pachman's >prescription, I would be very interested in seeing it. It would surely be quite >instructive. > > >>if there were no black pawn on c5, then Black would have sufficient >>counterplay to hold the draw, since his King could use the c5-square >>to attack White's pawns. >> >>Thus in our start position, White should NOT take the c-pawn, but >>instead make progress on the kingside by manoeuvering his knight. >> >>[D]8/8/4k3/2p1p1K1/2PbP1N1/8/8/8 b - - 0 9 >> >>Pichard.
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