Author: Robert Hyatt
Date: 06:49:54 10/14/99
Go up one level in this thread
On October 14, 1999 at 01:01:56, Howard Exner wrote: >On October 13, 1999 at 21:46:31, Steve Schooler wrote: > >>On October 13, 1999 at 21:39:33, Steve Schooler wrote: >> >>>On October 13, 1999 at 19:49:58, Jeremiah Penery wrote: >>> >>>>On October 13, 1999 at 17:23:14, Howard Exner wrote: >>>> >>>>>Here's an example of pawn majority knowledge. A program >>>>>with pawn majority knowledge of the queen side configuration in this >>>>>example may well find the winning move Qg6+. >>>>> >>>>>4Q3/6pk/2pq4/3p4/1p1P3p/1P1K1P2/1PP3P1/8 b - - bm Qg6; >>>>> >>>>>After the exchange of queens will follow the the advance of the black king to >>>>>the kingside, then exchanges of the kingside pawns, and finally the king can >>>>>march over to pick up the queenside pawns. Is knowledge that white cannot break >>>>>through on the queenside essential for solving this? Would any program find Qg6? >>>> >>>>I think Qg6 only draws. >>>> >>>>Here's a line: 1. ...Qg6 2. Qxg6 Kxg6 3. Ke3 Kf5 4. c3 g5 5. Ke2 Kf4 6. Kf2 g4 >>>>7. fxg4 Kxg4, and this will draw. >>>> >>>>Can black improve on this? >>>> >>>>Jeremiah >>> >>>I suspect that black may win by zugzwang : in above line >>> >>>4... Kg5 5. Ke2 Kf4 6. Kf2 g6 7. cxb4 g5 8. Kg1 Kg3 9. Kh1 h3 >>>10. gxh3 Kxh3 and (I think) black wins. >> >>In above line, from my previous post, I overlooked 8. b5. I now suspect that >>White can draw. > >This is on the right track, just keep playing it through. >1... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5 4. c3 Kg5 5. Ke2 Kf4 6. Kf2 g6 7. cxb4 >g5 8. b5 cxb5 9. b4 g4 10. fxg4 Kxg4 11. b3 Kf4 12. Kf1 > >I guess this position carries a bit of venom for programs. > >A. Programs are intimidated by the greater number of pawns for white on the >queenside, thus the reluctance to exchange Queens. Yet in this similar >position they may very well play Qg6. > >4Q3/6pk/2pq4/3p4/1p1P3p/1P1K1P2/2P3P1/8 b - - id Pos 1 - EXAMPLE.EPD; bm Qg6; > >It is different only in that the white pawn on b2 is missing. Both are similar >in that white cannot break through and force a passer though with the >extra b2 pawn white has some waiting moves that do not help since no passer >is available. > >B. The waiting move with the king 4 ...Kg5, compelling white to move. > >C. The liquidation theme, where after black exchanges the kingside pawns >the king is so dominant that it can move uncontested to the queenside. > >I posted this one about a year ago but no one posted that their program found >Qg6 back then. that was then, this is now. here is current crafty output: nss depth time score variation (1) 1 0.00 -0.24 1. ... c5 2. dxc5 Qxc5 1 0.04 -0.21 1. ... g5 1-> 0.05 -0.21 1. ... g5 2 0.05 -0.55 1. ... g5 2. Qh5+ Qh6 2 0.05 ++ 1. ... Qg6+!! 2 0.05 -0.10 1. ... Qg6+ 2. Qxg6+ Kxg6 3. f4 Kf5 2-> 0.05 -0.10 1. ... Qg6+ 2. Qxg6+ Kxg6 3. f4 Kf5 3 0.05 -0.10 1. ... Qg6+ 2. Qxg6+ Kxg6 3. f4 Kf5 4. Ke3 3-> 0.06 -0.10 1. ... Qg6+ 2. Qxg6+ Kxg6 3. f4 Kf5 4. Ke3 4 0.10 0.03 1. ... Qg6+ 2. Qxg6+ Kxg6 3. f4 Kf5 4. Ke3 g6 4-> 0.10 0.03 1. ... Qg6+ 2. Qxg6+ Kxg6 3. f4 Kf5 4. Ke3 g6 5 0.11 0.13 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5 4. Ke2 Kf4 5. Kd3 5-> 0.12 0.13 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5 4. Ke2 Kf4 5. Kd3 6 0.14 0.19 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5 4. Ke2 Kf4 5. Kd3 g5 6-> 0.16 0.19 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5 4. Ke2 Kf4 5. Kd3 g5 7 0.37 0.03 1. ... Qg6+ 2. Qxg6+ Kxg6 3. c4 bxc3 4. Kxc3 Kf5 5. Kb4 Ke6 6. Kc5 Kd7 7-> 0.51 0.03 1. ... Qg6+ 2. Qxg6+ Kxg6 3. c4 bxc3 4. Kxc3 Kf5 5. Kb4 Ke6 6. Kc5 Kd7 8 0.66 0.29 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5 4. Ke2 Kf4 5. Kf2 g6 6. Ke2 g5 8-> 0.83 0.29 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5 4. Ke2 Kf4 5. Kf2 g6 6. Ke2 g5 9 1.06 0.29 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5 4. Ke2 Kf4 5. Kf2 g5 6. Ke2 Kg3 7. Kf1 9-> 1.22 0.29 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5 4. Ke2 Kf4 5. Kf2 g5 6. Ke2 Kg3 7. Kf1 10 1.76 0.59 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5 4. Ke2 Kf4 5. Kf2 g5 6. Ke2 Kg3 7. Kf1 Kf4 10-> 2.15 0.59 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5 4. Ke2 Kf4 5. Kf2 g5 6. Ke2 Kg3 7. Kf1 Kf4 11 2.96 0.59 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5 4. Ke2 Kf4 5. Kf2 g5 6. Ke2 Kg3 7. Kf1 h3 8. gxh3 Kxf3 11-> 3.60 0.59 1. ... Qg6+ 2. Qxg6+ Kxg6 3. Ke3 Kf5 4. Ke2 Kf4 5. Kf2 g5 6. Ke2 Kg3 7. Kf1 h3 8. gxh3 Kxf3 ~ so at least now it has an inkling that this is good.
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