Author: John Merlino
Date: 10:06:05 01/01/03
Go up one level in this thread
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
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