[COMMENT DELETED] out of shame...
Is This Chess Position Illegal?
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Feb 23, 2011
0
#3
No,
This position is legal. A Black knight could have taken the bishop on f1 and then made its escape.
The White bisop on b3 is the result of an underpromotion. Notice that White has a pawn missing.
Barefoot_Player
Black's queen is hanging, is what's wrong with it.
Feb 23, 2011
0
#6
ivandh wrote:
Black's queen is hanging, is what's wrong with it.
Retrograde analysis, which is what this type of problem is, doesn't deal with what moves are "good," only which moves are "possible." In many a retrograde problem, the solution has you making all sorts of crazy moves that no player would ever make in real life - strange underpromotions, letting random pieces be taken for free just to let the pawns get to the right squares, capturing Bishops on their home square (as seen in this one), etc.
Someone ought to give smiley15's game to Rybka
EDIT: I have given the game to Crafty(Freeware chess engine, it comes with ICC's Dasher). The worst move of the game was 23... Kh8, a 17.9 pawn mistake, with the evaluation changing from -6.4 pawns to 11.5 pawns. The second worst move of the game came just before the worst, it was 23. c7, a 17.6 pawn mistake, with the evaluation changing from 11.2 pawns to -6.4 pawns.
omnipaul wrote:
ivandh wrote:
Black's queen is hanging, is what's wrong with it.
Retrograde analysis, which is what this type of problem is, doesn't deal with what moves are "good," only which moves are "possible." In many a retrograde problem, the solution has you making all sorts of crazy moves that no player would ever make in real life - strange underpromotions, letting random pieces be taken for free just to let the pawns get to the right squares, capturing Bishops on their home square (as seen in this one), etc.
Congratulations, you win a gold sticker! Please ignore the whooshing sound coming from above you.
I find it quite fun to search a chess board to see if a certain position is legal or not. And by legal, I mean it is a something you can find in a normal game. Is this position able to happen in an actual game? In other words, is this position legal or illegal? Post your answer, and tell me what you think the answer is. If illegal, also tell me what is wrong with the position. I'll post the solution when someone answers correctly.