Author: blass uri
Date: 23:53:23 09/02/98
Go up one level in this thread
On September 01, 1998 at 07:17:44, Howard Exner wrote: >Here are some positions taken from CCL games that proved difficult for the >computers to solve. They are 40/2 standard time control games played >on seperate P200's. How do other programs navigate these positions? > >1. Hiarcs6 played f7f5? which is a blunder because Qd5+ would easily win. It >seems that some positions that are easy for humans to solve can still pose >problems for computers.Why would programs find this position hard to solve? >8/5pk1/4p3/7Q/8/3q4/KP6/8 b - - id "Genius 5.0 - Hiarcs 6.0"; bm Qd5; Junior5(16 bit) has no problem to find Qd5+ with evaluation of more than 2 pawns advantage for black. It found it in a very short time(I think less than a second) > >2. Nimzo played the losing move, Kxb3 when Kxa4! would have been a routine draw. >8/8/8/5P2/Pk5K/1N6/6b1/8 b - - id "Genius 5.0 - Nimzo 98"; am Kxb3; Junior5 needed 6 minutes and 21 seconds to find Kxa4 on my pentium200MMX The evaluation was 2.01 pawns advantage for white. I am not sure if it is a draw(If you have database of 5 pieces you can check it) > >3. This position illustrates the trapped piece theme. Rxa2, played by Genius >5.0, should be avoided because of the game continuation ... >1. ... Rxa2 2. Rxa2 Bc4 3.Qd2 Bxa2 4. b3 and the bishop on a2 was eventually >lost. Junior5 did not think to play Rxa2 and prefered Nd7 >1q3rk1/p3b1pp/1n2p3/r2bPp2/1p6/4BN2/PPB1QPPP/R2R2K1 b - - id "Hiarcs 6.0 - >Genius 5.0"; am Rxa2; > >4. Hiarcs played Ke2 but Kxe7 is white's only practical chance of winning. Pawns >on both wings generally favour the Bishop over the Knight. Allowing opposite >bishops to remain (even with knights on the board) is an error in judgement in >this position. >8/4bkp1/2N2n2/8/8/2pB3P/5PP1/5K2 w - - id "Hiarcs 6.0 - Nimzo 98; bm Nxe7; Junior prefered Bc4+ Kf8 Ke2 and I am not sure about the right move. >7. Avoid the move 1.Rh5 because 1. ... Rh6! 2. Bxf5 Rxh5 3.Bxh3 and black is >winning because of the passed h pawn combined with the advance of the king. >Nimzo did play Rh6 and lost. A better try is the simple 1. Bxf5 Bxf5 2. Rxh4. >7R/5k2/1r6/1pN2n2/1Pp4p/2P4b/1K6/1B6 w - - id "Nimzo 98 - Shredder 2.0"; am Rh5; Junior needed 5 minutes and 35 seconds to find the mistake Rh5 instead of the right move 1.Bxf5 and it needed 40 minutes and 43 seconds to reject it again for Bxf5. It did not reject Rh5 because it believed Rh5 is a losing move but because it evaluated Bxf5 as a bigger advantage for white(The advantages are small) > >8. Shredder2 should play Qb8. Instead Shredder played 1. ... Ng4? 2. f4 Nxe3 3. >Qxb2 Nxf1 4. fxe5 and now the Knight on f1 is trapped. >3r2k1/2qp1ppp/2p1pn2/4b3/4P3/2PBB3/Pr3PPP/R1Q2R1K b - - id "Nimzo 98 - Shredder >2.0"; am Ng4; Junior needed 14 minutes and 34 seconds to reject Ng4. It did not like Qb8 but prefered Qb7 It did not think to play 3...Nxf1 when it considered 1...Ng4 but prefered 3...Bxf4 Uri
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