legal AND illegal positions
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Legal. Can definately be shortened, tho.
who wins this game?
I dont get it
Whats the point of this?
Apr 30, 2011
0
#468
Post #504 is illegal.
The h5 Black pawn captured 2 major White pieces to get there from f7 (as the White g pawn is on h3). Since White has all of his major pieces present on the shown board position, 2 of the White pawns must have promoted, and these must be the e and f pawns. The White f pawn can easily promote. However, the White e pawn must have captured in order to promote and there are no more Black pieces left to capture (if you account for the 4 other captures that must have taken place in order to get the existing White pawns on their board positions).
OK, as usual, I'll just hang around now and wait for someone much smarter than me to post a clever solution to the problem showing that its legal.
ILuvPawn wrote:
Post #504 is illegal.
The h5 Black pawn captured 2 major White pieces to get there from f7 (as the White g pawn is on h3). Since White has all of his major pieces present on the shown board position, 2 of the White pawns must have promoted, and these must be the e and f pawns. The White f pawn can easily promote. However, the White e pawn must have captured in order to promote and there are no more Black pieces left to capture (if you account for the 4 other captures that must have taken place in order to get the existing White pawns on their board positions).
OK, as usual, I'll just hang around now and wait for someone much smarter than me to post a clever solution to the problem showing that its legal.
Knowing einstein, he may, in fact, have that clever solution in store for us... but I can't find it.
White MUST have played cxb3, bxa4, dxc3, and gxh3 during the game, and this accounts for all missing Black pieces (since there are only 4); this means no other White pawns changed files. Similarly, Black MUST have played fxg6 and gxh5, which accounts for both missing White pieces; consequently, no other Black pawns changed files.
Since a4 can only come from c2, c3 from d2, and h3 from g2, the missing White pawns MUST have started on e2 and f2. Neither pawn could have changed files, and neither pawn could have reached g6 or h5 without changing files or promoting; so the e2 and f2 pawns MUST have both promoted (on the e and f files, respectively).
Additionally, no Black pawn other than the one on h5 changed files, so e4 came directly from e7. But for White's e2 pawn to promote, at least one side's e-pawn MUST have changed files... I can't find a way around this contradiction.
...don't quote me on that, though. 
P.S. - have you gotten any further with this one? Only about a day left before I post the solution myself!
Post #504 is definetly illegal, not enough capture material. I tried it =)
May 2, 2011
0
#471
The position I posted is illegal. I didn't throw in any tricks this time. :) I haven't done any further work on yours, cobra91.
Legal or Illegal?
legal or illegal?
Post #512 is illegal because there's no way white's knight could get to d6 on the last move.
Jun 1, 2011
0
#475
TheMouse wrote:
ILuvPawn wrote:
Post #504 is illegal.
The h5 Black pawn captured 2 major White pieces to get there from f7 (as the White g pawn is on h3). Since White has all of his major pieces present on the shown board position, 2 of the White pawns must have promoted, and these must be the e and f pawns. The White f pawn can easily promote. However, the White e pawn must have captured in order to promote and there are no more Black pieces left to capture (if you account for the 4 other captures that must have taken place in order to get the existing White pawns on their board positions).
OK, as usual, I'll just hang around now and wait for someone much smarter than me to post a clever solution to the problem showing that its legal.
In post #504 both kings are in check. A simpler way of proving the position is illegal.
I was referring to the post above, currently post #503. Someone closed their account and and all the post numbers shifted. No doubt by the time the next person replies to this it will be post #502.
yeah I noticed too, all post numbers shifted. I wish they wouldn't do that chess.com =P
#512 illegal, white's last move knight check, but knight couldn't have come from anywhere
juju2 wrote:
juju2 wrote:
Illegal. White would have had to move one of his queens to either c7 or b6 while the other was already at the other of those squares, meaning that Black would have had to move while in stalemate.
TheMouse wrote:
legal
LOL
What were black and white's last moves?That one is illegal and here is why
look at blacks dark bishop, how did it get to that square if the pawns never moved.
Also if you go back 1 move, blacks last move had to be g6 because nothing else would have been legal, and white was on g8 with his king and this proves that the white king never had a path to get to blacks back rank
However if I am looking at the position wrong, and all those pawns are headed up instead of down I think it is probably legal
your right about the king's path had the move been g6.
You wrong about the bishop, what do you mean, it may have just come back in through a diagonal that the e pawn opened up.
and anyway it is legal, look up a few posts, ive posted a diagram on it.