Author: John Merlino
Date: 18:17:38 01/01/03
Go up one level in this thread
On January 01, 2003 at 17:15:52, Roy Brunjes wrote: >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 > >I am using the Chessmaster personality -- give it more time and it will switch >to Rxb2 (after having played ... Rc2 and white's Rg1. > >Roy Noted. Interesting. Well, it will play the right move in a blitz game! :-) jm
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