It's impossible for both sides - black and white to promote all 16 pawns to Q. Think about how each side would get ALL the pawns to the queenning square. There are not enough non-pawn pieces on the board to facilitate the column manuevering for the pawns to pass each other. It is not "highly improbable" , but 100% impossible.Milos wrote:Why it is not possible???MikeB wrote: The position is not possibe from a real game of chess - but Crafty sees the 8+1 queens on both sides and is happy to oblige.
It's quite possible, it's however highly improbable.
Still looking for the engine that can analyze this position
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Re: Still looking for the engine that can analyze this posit
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Re: Still looking for the engine that can analyze this posit
The position in question certainly should be flagged since one side has 31 queens...mhalstern wrote:The fritz12 Gui dosen't understand the illegality of the position and will let any engine play from it. It only considers illegal positions as those with more extra pieces than pawns could have been promoted to.
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Re: Still looking for the engine that can analyze this posit
It it likely the position is reachable. One has 6 pieces to sacrifice to open holes in the pawn structure, and both sides can then push pawns through those holes ignoring captures if they want. I'd have to think pretty long on this to decide if it is really a reachable position or not, and I don't intend to ever include this kind of legality test in Crafty since it is computationally intractable...MikeB wrote:slightly different twist -Dann Corbit wrote:[d]qqqqkqqq/qqqqqqqq/qqqqqqqq/qqqqqqqq/QQQQQQQQ/QQQQQQQQ/QQQQQQQQ/QQQQKQQQ w - -
What do you mean it's not a real chess position? I want to see it analyzed.
So far, every engine has crashed instantly except Rybka of all the engines that I tried, but Rybka refused to utter a single syllable after 15 mintues of thought. I think the slimy fish knows the answer, but he's not telling just to spite me.
max threads set to 1.
White(1): [d] 3qk3/qqqqqqqq/8/8/8/8/QQQQQQQQ/3QK3 w - - 0 0Crafty has no output for 13 seconds and then annouces mate-in-4. The position is not possibe from a real game of chess - but Crafty sees the 8+1 queens on both sides and is happy to oblige. One oddity whether I use four cores or one core, Crafty takes about the same amount of time with the about same # of nps.Code: Select all
White(1): g time surplus 0.00 time limit 30:00 (+0.00) (30:00) depth time score variation (1) 1 13.11 12.68 1. Qaxf7+ (4.4Mnps) 1-> 13.14 12.68 1. Qaxf7+ (4.4Mnps) 2 13.14 12.68 1. Qaxf7+ Qxf7 2. Qcxh7 2-> 13.17 12.68 1. Qaxf7+ Qxf7 2. Qcxh7 3 13.19 12.68 1. Qaxf7+ Qxf7 2. Qcxh7 3-> 13.20 12.68 1. Qaxf7+ Qxf7 2. Qcxh7 4 13.22 +1 1. Qaxf7+! 4 13.22 +3 1. Qaxf7+! 4 13.22 +M 1. Qaxf7+! 4 13.22 Mat04 1. Qaxf7+ Qxf7 2. Qh8+ Qxh8 3. Qxh8+ Qf8 4. Qhxf8# 4-> 13.25 Mat04 1. Qaxf7+ Qxf7 2. Qh8+ Qxh8 3. Qxh8+ Qf8 4. Qhxf8# 5 13.25 Mat04 1. Qaxf7+ Qxf7 2. Qh8+ Qxh8 3. Qxh8+ Qf8 4. Qgg6# 5-> 13.26 Mat04 1. Qaxf7+ Qxf7 2. Qh8+ Qxh8 3. Qxh8+ Qf8 4. Qgg6# 6 13.28 Mat04 1. Qaxf7+ Qxf7 2. Qh8+ Qxh8 3. Qxh8+ Qf8 4. Qgg6# 6-> 13.30 Mat04 1. Qaxf7+ Qxf7 2. Qh8+ Qxh8 3. Qxh8+ Qf8 4. Qgg6# 7 13.31 Mat04 1. Qaxf7+ Qxf7 2. Qh8+ Qxh8 3. Qxh8+ Qf8 4. Qgg6# 7-> 13.34 Mat04 1. Qaxf7+ Qxf7 2. Qh8+ Qxh8 3. Qxh8+ Qf8 4. Qgg6# time=13.36 mat=0 n=58429045 fh=98% nps=4.4M extensions=566 qchecks=10K reduced=959 pruned=18K predicted=0 evals=64K 50move=0 EGTBprobes=0 hits=0 SMP-> splits=0 aborts=0 data=0/256 elap=13.36 mate in 4 moves. White(1): Qaxf7+ time used: 13.36 Black(1):
But clearly positions with > 9 queens on one side, or > 10 n/b/r on one side can't be reached, ever, and Crafty does detect those.
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Re: Still looking for the engine that can analyze this posit
Why? one can first create 8 new queens, then shuffle them at will to reach that position...Graham Banks wrote:Wouldn't the last move have had to have been a pawn promoting to a queen, in which case the square from which it had moved would be empty?Milos wrote:Why it is not possible???MikeB wrote: The position is not possibe from a real game of chess - but Crafty sees the 8+1 queens on both sides and is happy to oblige.
It's quite possible, it's however highly improbable.
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Re: Still looking for the engine that can analyze this posit
Here's an idea. White sacrifices 4 pieces to double black pawns on the a, c, e and g files. Black sacrifices 4 pieces to double white pawns on the b, d, f and h files. Now you just push the pawns up the ranks and promote them one at a time.MikeB wrote:It's impossible for both sides - black and white to promote all 16 pawns to Q. Think about how each side would get ALL the pawns to the queenning square. There are not enough non-pawn pieces on the board to facilitate the column manuevering for the pawns to pass each other. It is not "highly improbable" , but 100% impossible.Milos wrote:Why it is not possible???MikeB wrote: The position is not possibe from a real game of chess - but Crafty sees the 8+1 queens on both sides and is happy to oblige.
It's quite possible, it's however highly improbable.
I don't see why it is impossible...
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Re: Still looking for the engine that can analyze this posit
Suggest what the last move could have been. I'm looking at the position where there are no empty squares on the board.bob wrote:Why? one can first create 8 new queens, then shuffle them at will to reach that position...Graham Banks wrote:Wouldn't the last move have had to have been a pawn promoting to a queen, in which case the square from which it had moved would be empty?Milos wrote:Why it is not possible???MikeB wrote: The position is not possibe from a real game of chess - but Crafty sees the 8+1 queens on both sides and is happy to oblige.
It's quite possible, it's however highly improbable.
gbanksnz at gmail.com
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Re: Still looking for the engine that can analyze this posit
We are not talking about that position. That one is clearly impossible (and illegal).Graham Banks wrote:Suggest what the last move could have been. I'm looking at the position where there are no empty squares on the board.
We are talking about this one:
[d] 3qk3/qqqqqqqq/8/8/8/8/QQQQQQQQ/3QK3 w - - 0 0
which is perfectly legal and possible.
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Re: Still looking for the engine that can analyze this posit
Okay. My bad.Milos wrote:We are not talking about that position. That one is clearly impossible (and illegal).Graham Banks wrote:Suggest what the last move could have been. I'm looking at the position where there are no empty squares on the board.
We are talking about this one:
[d] 3qk3/qqqqqqqq/8/8/8/8/QQQQQQQQ/3QK3 w - - 0 0
which is perfectly legal and possible.
gbanksnz at gmail.com
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Re: Still looking for the engine that can analyze this posit
Good point _ didn't think of that.bob wrote:Here's an idea. White sacrifices 4 pieces to double black pawns on the a, c, e and g files. Black sacrifices 4 pieces to double white pawns on the b, d, f and h files. Now you just push the pawns up the ranks and promote them one at a time.MikeB wrote:It's impossible for both sides - black and white to promote all 16 pawns to Q. Think about how each side would get ALL the pawns to the queenning square. There are not enough non-pawn pieces on the board to facilitate the column manuevering for the pawns to pass each other. It is not "highly improbable" , but 100% impossible.Milos wrote:Why it is not possible???MikeB wrote: The position is not possibe from a real game of chess - but Crafty sees the 8+1 queens on both sides and is happy to oblige.
It's quite possible, it's however highly improbable.
I don't see why it is impossible...
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Re: Still looking for the engine that can analyze this posit
Just for kicks , I had crafty compute the starting chess position , substituting Qs for Ps. First ply took 65 minutes to compute. I know that position is impossible for.sure!.