Author: Steven J. Brann
Date: 16:40:21 01/02/03
Go up one level in this thread
On January 01, 2003 at 13:06:05, John Merlino wrote: >On January 01, 2003 at 11:41:37, Roy Brunjes wrote: > >>I came across this endgame in a software course I am using for chess training. >>I gave the position to Hiarcs 8, Junior 7, and Chessmaster 9000 and they seem to >>miss the point. I am wondering what Fritz 8 and Shredder 7 have to say about >>it. >> >>[D] 5k2/7p/6p1/1p3p2/2r2P2/5P2/PP5P/5K1R b - - >> >>In this position, with Black to move, Rc2 is the stated best move. I have no >>argument with that and neither do any of the programs I tried. The rub comes >>after this: >> >>1. ... Rc2 >>2. Rg1 >> >>Which gives this position: >> >>[D] 5k2/7p/6p1/1p3p2/5P2/5P2/PPr4P/5KR1 w - - >> >>Now White is attempting to activate his rook. Programs I have tried (listed >>above) all want to play 2. ... Rxb2 after searches running for 3-4 minutes >>(admiteddly on my slow PIII 500 MHz laptop). This leads to a much more >>difficult ending that Hiarcs 8 was unable to win against me (and I'm a Class C >>player) at a time control of 10 mins + 10 secs per move. That tells me that the >>move Rxb2 is probably not best. >> >>The training software says 2. ... Rxb2 is a mistake and instead recommends 2. >>... Rxh2! >> >>Then, after 2. ... Rxh2 comes 3. Rg2 Rxg2 4. Kxg2. Now both sides bring Kings >>to the center and Black must use his passed pawn on the h file to distract the >>White King from his job of keeping Black's King away from his pawns on a2 and >>b2. Once the White King is forced to head toward the Black h pawn, the invasion >>of the Black King wins the game. >> >>My question is this: What programs will play 2. ... Rxh2? And 3. ... Rxg2 >>[after 3. Rg2 by White] instead of 3. ... Rh4, and after how much time? >>Chessmaster 9000 wants to play 2. ... Rxh2 for a bit but then opts for 2. ... >>Rxb2 instead after a search of 7/12 ply. It seems to stick with that for quite >>a while and then finally changes back to 2. ... Rxh2 at ply 10/15 (4 minutes 25 >>seconds on my old, slow PIII-500 laptop). >> >>It seems to me that the principles are pretty clear and that a good endgame >>playing program should not need huge amounts of CPU time to select the right >>plan. >> >>Thanks in advance for putting Fritz 8 and Shredder 7 to the test. Feel free to >>try it with other programs as well -- I have particular interest in those two >>however as they are newer and I have no access to them. So far, only CM9000 >>does find the right sequence of moves, though it takes quite a few ply to do so. >> Yes, of course my faster computers would get there quicker, but still, they >>will require just as many ply to see the win. I would have thought a program >>with lots of endgame knowledge could spot the win fairly quickly. >> >>Lastly, Happy New Year to all CCC readers! >> >>Roy > >My Chessmaster 9000, using the default persaonlity on a P3-733 from the INITIAL >position, immediately says 1...Rc2 2.Rg1 Rxh2, with a decent score for Black. >I'm not sure where your 2...Rxb2 is coming from. Are you using a custom >personality? > >Time Depth Score Positions Moves >0:00 1/3 -0.49 456 1...Rc2 2.h4 Rxb2 3.a3 >0:00 1/4 -0.67 1350 1...Rc2 2.Rg1 Rxh2 3.Rg2 Rh5 >0:00 1/5 -0.66 3082 1...Rc2 2.Rg1 Rxh2 3.Rg2 Rh4 >0:00 1/6 -0.92 5534 1...Rc2 2.Rg1 Rxh2 3.Rg2 Rh4 4.Rd2 > Rxf4 >0:00 2/7 -0.85 11549 1...Rc2 2.Rg1 Rxh2 3.Rg2 Rh4 4.Rd2 > Rxf4 5.Kg2 >0:00 3/8 -0.88 66062 1...Rc2 2.Rg1 Rxh2 3.Rg2 Rh4 4.Rc2 > Rxf4 5.Rc8+ Ke7 6.Kg2 >0:01 4/9 -0.87 103239 1...Rc2 2.Rg1 Rxh2 3.Rg2 Rh4 4.Rd2 > Rxf4 5.Kg2 Rh4 6.Kg3 >0:01 5/10 -0.88 204229 1...Rc2 2.Rg1 Rxh2 3.Rg2 Rh4 4.Rc2 > Rxf4 5.Rc5 b4 6.Rc8+ Ke7 7.Kg2 >0:04 6/11 -0.89 520480 1...Rc2 2.Rg1 Rxh2 3.Rg2 Rh4 4.Rc2 > Rxf4 5.Rc8+ Ke7 6.Rb8 b4 7.Rb7+ > Ke6 8.Kg2 >0:13 7/12 -0.86 1374275 1...Rc2 2.Rg1 Rxh2 3.Rg2 Rh4 4.Rc2 > Rxf4 5.Rc5 b4 6.Kg2 Rh4 7.Rc8+ > Kf7 8.a4 bxa3ep 9.bxa3 >0:35 8/13 -0.86 3984633 1...Rc2 2.Rg1 Rxh2 3.Rg2 Rh4 4.Rc2 > Rxf4 5.Rc5 b4 6.Kf2 Rh4 7.Kg3 Rh5 > 8.a4 bxa3ep 9.bxa3 > >jm CM9000 on my P4 1.9G puter sniffs at 2...Rxb2 at 13 seconds, but returns to Rxh2 quickly. Default personality with 128M hash and SS = 12. Perhaps the analysis was stopped immediately after it found 2...Rx b2. Time Depth Score Positions Moves 0:00 1/9 -0.87 80561 1...Rc2 2.Rg1 Rxh2 3.Rg2 Rh4 4.Rd2 Rxf4 5.Kg2 Rh4 6.Kg3 0:00 2/10 -0.88 112536 1...Rc2 2.Rg1 Rxh2 3.Rg2 Rh4 4.Rc2 Rxf4 5.Rc5 b4 6.Rc8+ Ke7 7.Kg2 0:01 3/11 -0.89 238886 1...Rc2 2.Rg1 Rxh2 3.Rg2 Rh4 4.Rc2 Rxf4 5.Rc8+ Ke7 6.Rb8 b4 7.Rb7+ Ke6 8.Kg2 0:02 4/12 -0.86 508899 1...Rc2 2.Rg1 Rxh2 3.Rg2 Rh4 4.Rc2 Rxf4 5.Rc5 b4 6.Kg2 Rh4 7.Rc8+ Kf7 8.a4 bxa3ep 9.bxa3 0:05 5/13 -0.86 1384562 1...Rc2 2.Rg1 Rxh2 3.Rg2 Rh4 4.Rc2 Rxf4 5.Rc5 b4 6.Kf2 Rh4 7.Kg3 Rh5 8.a4 bxa3ep 9.bxa3 0:13 6/14 -0.87 3389899 1...Rc2 2.Rg1 Rxb2 3.Rg2 Rb4 4.Ke2 Rxf4 5.Ke3 Rc4 6.Rd2 Ke7 7.Rd5 Rc3+ 8.Kf4 b4 0:35 7/15 -0.88 9156668 1...Rc2 2.Rg1 Rxh2 3.Rg2 Rh4 4.Rc2 Rxf4 5.Rc5 b4 6.Kf2 h5 7.Kg3 g5 8.a4 h4+ 9.Kg2 h3+ 10.Kg3 1:27 8/16 -0.93 23047374 1...Rc2 2.Rg1 Rxh2 3.Rg2 Rxg2 4.Kxg2 Kf7 5.Kf2 Ke6 6.Ke3 Kd5 7.Kf2 Kd4 8.Kg3 h6 9.a3 Kc4 10.Kf2 Kd5 11.Ke3 3:24 9/17 -0.99 55510207 1...Rc2 2.Rg1 Rxh2 3.Rg2 Rxg2 4.Kxg2 Kf7 5.Kf2 Ke6 6.Ke3 Kd5 7.Kf2 Kd4 8.Kg3 h6 9.Kg2 h5 10.Kg3 Ke3 11.a3 8:12 10/18 -0.95 135108583 1...Rc2 2.Rg1 Rxh2 3.Rg2 Rxg2 4.Kxg2 Kf7 5.Kf2 Ke6 6.Ke3 Kd5 7.Kf2 Kd4 8.Kg3 h6 9.Kg2 h5 10.Kg3 Ke3 11.a3 Kd4 Steve
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