Author: Robert Hyatt
Date: 14:26:03 10/03/05
Go up one level in this thread
On October 03, 2005 at 13:30:42, Joseph Tadeusz wrote: >On October 03, 2005 at 11:43:22, Robert Hyatt wrote: > >>On October 02, 2005 at 13:49:37, Will Singleton wrote: >> >>>White wins easily by promoting and exchanging queens, but most comps can't see >>>it. >>> >>>[d]8/5p1P/8/8/6K1/5P2/1k6/q7 w - - >>> >>>Amateur failed to exchange queens, and drew the game. I'm not quite sure why, >>>seems like a simple search should be enough to handle this. Oddly, if the >>>exchange is forced, the win is seen immediately. This happens with other progs >>>as well. I thought I had taken steps to eliminate root-position dependencies in >>>the search, but maybe something else is happening. >>> >>>Will >> >> >>Here is what you need: >> >>Your program probably understands that if you remove the black queen, white is >>winning because of the "outside passed pawn"??? (ignore the fact that the pawn >>promotes instantly for now). If so, you need one more critical piece of >>knowledge. >> >>Your program needsd to realize that if things are not obvious, no pawn to >>promote, no distant passer on the board, but its king is closer to the remaining >>pawns than the enemy king, the game is _still_ won. >> >>Set up a position like white/black pawns locked up at a4/a5, white passer at h2, >>both kings near the center of the board. The easiest way to win is to push the >>h-pawn. Black has to go over and stop it, and once it is gone, white is too >>close to the remaining black a-pawn and the game is over. >> >>If you don't catch this case, you will play for a distant passer, but then >>refuse to give it up, and once your king gets to the distant passer to defend >>it, you can't force the promotion, and when you wait too long, as your king >>finally gives up the passer, black eats it and then follows you across the board >>and hems in your king on the a-file or else black gets to the a-file and the >>game is a draw. But if you just push and get the black king too far away, you >>win easily... >> >>Crafty plays this move instantly with no endgame tables of any kind, and shows a >>big +score for white immediately, due to the above... > >This is incorrect: > > 9 0.41 2.84 1. h8=Q+ Ka2 2. Qxa1+ Kxa1 3. Kf5 Kb1 > 4. Kf6 Kc2 5. f4 Kd3 6. Kxf7 Ke4 > 9-> 0.43 2.84 1. h8=Q+ Ka2 2. Qxa1+ Kxa1 3. Kf5 Kb1 > 4. Kf6 Kc2 5. f4 Kd3 6. Kxf7 Ke4 > 10 1.09 -1 1. h8=Q+ > 10 17.50 1.36 1. h8=Q+ Ka2 2. Qa8+ Kb2 3. Qb7+ Kc2 > 4. Qxf7 Qg1+ 5. Kf5 Qc5+ 6. Kg6 Qg1+ > 7. Kh6 Qh2+ 8. Kg7 Qe5+ 9. Qf6 Qd5 > 10-> 17.57 1.36 1. h8=Q+ Ka2 2. Qa8+ Kb2 3. Qb7+ Kc2 > 4. Qxf7 Qg1+ 5. Kf5 Qc5+ 6. Kg6 Qg1+ > 7. Kh6 Qh2+ 8. Kg7 Qe5+ 9. Qf6 Qd5 > 11 28.03 1.36 1. h8=Q+ Ka2 2. Qa8+ Kb2 3. Qb7+ Kc2 > 4. Qxf7 Qg1+ 5. Kf5 Qc5+ 6. Kg6 Qg1+ > 7. Kh6 Qh2+ 8. Kg7 Qe5+ 9. Kh7 Kd3 > 10. f4 > 11-> 28.20 1.36 1. h8=Q+ Ka2 2. Qa8+ Kb2 3. Qb7+ Kc2 > 4. Qxf7 Qg1+ 5. Kf5 Qc5+ 6. Kg6 Qg1+ > 7. Kh6 Qh2+ 8. Kg7 Qe5+ 9. Kh7 Kd3 > 10. f4 > >After the exchange (4 plies): > >[D] 8/5p2/8/8/6K1/5P2/8/k7 w - - > > > 1 0.00 0.66 1. Kg5 > 1-> 0.00 0.66 1. Kg5 > 2 0.00 0.56 1. Kg5 Kb1 > 2-> 0.00 0.56 1. Kg5 Kb1 > 3 0.01 0.64 1. Kg5 Kb1 2. f4 > 3 0.01 +1 1. Kf5!! > 3 0.01 +3 1. Kf5!! > 3 0.01 1.96 1. Kf5 Kb1 2. Ke5 > 3-> 0.01 1.96 1. Kf5 Kb1 2. Ke5 > 4 0.01 +1 1. Kf5!! > 4 0.01 2.94 1. Kf5 Kb1 2. Kf6 Kc2 3. Kxf7 > 4-> 0.01 2.94 1. Kf5 Kb1 2. Kf6 Kc2 3. Kxf7 > 5 0.01 2.94 1. Kf5 Kb1 2. Kf6 Kc2 3. Kxf7 > 5-> 0.02 2.94 1. Kf5 Kb1 2. Kf6 Kc2 3. Kxf7 > 6 0.02 2.94 1. Kf5 Kb1 2. Kf6 Kc2 3. f4 Kd3 4. > Kxf7 > 6-> 0.02 2.94 1. Kf5 Kb1 2. Kf6 Kc2 3. f4 Kd3 4. > Kxf7 > 7 0.02 2.94 1. Kf5 Kb1 2. Kf6 Kc2 3. f4 Kd3 4. > Kxf7 > 7-> 0.03 2.94 1. Kf5 Kb1 2. Kf6 Kc2 3. f4 Kd3 4. > Kxf7 > 8 0.04 2.84 1. Kf5 Kb1 2. Kf6 Kc2 3. f4 Kd3 4. > Kxf7 Ke4 > 8-> 0.04 2.84 1. Kf5 Kb1 2. Kf6 Kc2 3. f4 Kd3 4. > Kxf7 Ke4 > 9 0.05 -1 1. Kf5 > 9 0.06 0.38 1. Kf5 Kb1 2. f4 Kc2 3. Kg5 Kd3 4. > f5 Ke3 5. f6 > 9-> 0.08 0.38 1. Kf5 Kb1 2. f4 Kc2 3. Kg5 Kd3 4. > f5 Ke3 5. f6 > 10 0.09 0.28 1. Kf5 Kb1 2. f4 Kc2 3. Kg5 Kd3 4. > f5 Ke3 5. f6 Kf3 > 10-> 0.10 0.28 1. Kf5 Kb1 2. f4 Kc2 3. Kg5 Kd3 4. > f5 Ke3 5. f6 Kf3 > 11 0.13 0.28 1. Kf5 Kb1 2. f4 Kc2 3. Kf6 Kd3 4. > f5 Ke4 5. Kg5 Kf3 6. f6 > 11 0.16 0.38 1. f4 Kb2 2. f5 Kc3 3. f6 Kd2 4. Kf4 > Ke2 5. Ke4 Kf2 6. Kf5 > 11-> 0.17 0.38 1. f4 Kb2 2. f5 Kc3 3. f6 Kd2 4. Kf4 > Ke2 5. Ke4 Kf2 6. Kf5 > 12 0.22 0.28 1. f4 Kb2 2. f5 Kc3 3. f6 Kd4 4. Kf4 > Kd3 5. Ke5 Ke3 6. Kf5 Kf3 > 12-> 0.25 0.28 1. f4 Kb2 2. f5 Kc3 3. f6 Kd4 4. Kf4 > Kd3 5. Ke5 Ke3 6. Kf5 Kf3 > 13 0.29 0.28 1. f4 Kb2 2. f5 Kc3 3. f6 Kc4 4. Kg5 > Kc5 5. Kh6 Kd5 6. Kh7 Ke5 7. Kg7 > 13-> 0.32 0.28 1. f4 Kb2 2. f5 Kc3 3. f6 Kc4 4. Kg5 > Kc5 5. Kh6 Kd5 6. Kh7 Ke5 7. Kg7 > 14 0.43 +1 1. f4!! > 14 0.47 +3 1. f4!! > 14 0.52 1.80 1. f4 Kb1 2. f5 Kc2 3. Kf4 Kd3 4. Ke5 > Ke3 5. f6 Kf3 6. Kd6 Kf4 7. Ke7 Ke5 > 8. Kxf7 > 14-> 0.56 1.80 1. f4 Kb1 2. f5 Kc2 3. Kf4 Kd3 4. Ke5 > Ke3 5. f6 Kf3 6. Kd6 Kf4 7. Ke7 Ke5 > 8. Kxf7 > 15 0.61 1.80 1. f4 Kb1 2. f5 Kc2 3. Kf4 Kd3 4. Ke5 > Ke3 5. f6 Kf3 6. Kd6 Kf4 7. Ke7 Ke5 > 8. Kxf7 > 15-> 0.65 1.80 1. f4 Kb1 2. f5 Kc2 3. Kf4 Kd3 4. Ke5 > Ke3 5. f6 Kf3 6. Kd6 Kf4 7. Ke7 Ke5 > 8. Kxf7 > 16 0.71 +1 1. f4!! > 16 0.76 +3 1. f4!! > 16 0.83 +M 1. f4!! > 16 0.95 6.95 1. f4 Kb2 2. Kf5 Kc3 3. Ke5 Kd3 4. > f5 Ke3 5. f6 Kf3 6. Kd6 Ke2 7. Ke7 > Kf2 8. Kxf7 Kf3 > 16-> 1.01 6.95 1. f4 Kb2 2. Kf5 Kc3 3. Ke5 Kd3 4. > f5 Ke3 5. f6 Kf3 6. Kd6 Ke2 7. Ke7 > Kf2 8. Kxf7 Kf3 > 17 1.05 -1 1. f4 > 17 1.15 2.72 1. f4 Kb2 2. Kf5 Kc3 3. Ke5 Kd3 4. > f5 Ke3 5. f6 Kf3 6. Kd6 Kg3 7. Ke7 > Kf4 8. Kxf7 Kf5 9. Kg7 > 17-> 1.21 2.72 1. f4 Kb2 2. Kf5 Kc3 3. Ke5 Kd3 4. > f5 Ke3 5. f6 Kf3 6. Kd6 Kg3 7. Ke7 > Kf4 8. Kxf7 Kf5 9. Kg7 > 18 1.26 +1 1. f4!! > 18 1.36 +3 1. f4!! > 18 1.44 +M 1. f4!! > 18 1.57 7.87 1. f4 Kb2 2. Kf5 Kc3 3. Ke5 Kd2 4. > f5 Kd3 5. f6 Ke3 6. Kd6 Kf3 7. Ke7 > Kf4 8. Kxf7 Kf5 9. Kg7 Kg4 > 18-> 1.65 7.87 1. f4 Kb2 2. Kf5 Kc3 3. Ke5 Kd2 4. > f5 Kd3 5. f6 Ke3 6. Kd6 Kf3 7. Ke7 > Kf4 8. Kxf7 Kf5 9. Kg7 Kg4 > 19 1.71 -1 1. f4 > 19 1.88 5.32 1. f4 Kb2 2. Kf5 Kc3 3. Ke5 Kd2 4. > f5 Kd3 5. f6 Ke3 6. Kd6 Ke4 7. Ke7 > Kf4 8. Kxf7 <HT> > 19-> 1.95 5.32 1. f4 Kb2 2. Kf5 Kc3 3. Ke5 Kd2 4. > f5 Kd3 5. f6 Ke3 6. Kd6 Ke4 7. Ke7 > Kf4 8. Kxf7 <HT> > 20 2.03 +1 1. f4!! > 20 2.15 +3 1. f4!! > 20 2.28 +M 1. f4!! > 20 2.52 10.21 1. f4 Kb2 2. Kf5 Kc3 3. Ke5 f5 4. Kxf5 > Kd3 5. Ke5 Ke3 6. f5 Kf3 7. f6 Ke2 > 8. f7 Ke3 9. f8=Q Ke2 10. Kd6 Ke3 > 20-> 2.58 10.21 1. f4 Kb2 2. Kf5 Kc3 3. Ke5 f5 4. Kxf5 > Kd3 5. Ke5 Ke3 6. f5 Kf3 7. f6 Ke2 > 8. f7 Ke3 9. f8=Q Ke2 10. Kd6 Ke3 > >It takes still 14 ply to see a big advantage. That is a version with a couple of serious bugs that have been fixed in 20.1... But it really does not matter whether it sees "big advantage" or not here. What matters is that it understands that when the queens come off, white is better, which is correct...
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