Posers and Puzzles
18 Jun 05
18 Jun 05
Originally posted by BigDoggProblemof course its not, why would you ask if it was?
[fen]8/5N2/2kP1r2/7b/P7/6KB/7r/2R3BQ[/fen]
Is the position legal?
can't have double check with the queen and rook, also, if the queen was to check, it can't have moved, which means that the rook was blocking it, meaning that BLACK moved his rook out of the way, leaving the queen checking, an illegal move.
18 Jun 05
Originally posted by abejnoodWhy is there a pawn on a4?
of course its not, why would you ask if it was?
can't have double check with the queen and rook, also, if the queen was to check, it can't have moved, which means that the rook was blocking it, meaning that BLACK moved his rook out of the way, leaving the queen checking, an illegal move.
18 Jun 05
1 edit
Okay, then the position is perfectly legal (only you have to assume two en passants happened)
Let's see if I can get the Fen right from the first try:
So the last moves were 1.g4 fxg++ 2.Kxg3+ d5 3.cxd#
EDIT: sorry didn't get the fen right from the first time 🙁
18 Jun 05
1 edit
Originally posted by ilywrinThat's right, ilywrin. Two ep captures must have occurred for the position to be legal. The problem was composed by Pal Benko and appeared in StrateGems in 1999.
Okay, then the position is perfectly legal (only you have to assume two en passants happened)
Let's see if I can get the Fen right from the first try:
[fen]8/3p1N2/2k2r2/2P4b/P4p2/5K1B/6Pr/2R3BQ w - - 0 1 [/fen]
So the last moves wer ...[text shortened]... cxd#
EDIT: sorry didn't get the fen right from the first time 🙁
Pa4 and Nf7 appear to be only needed for the finale to be mate. (An 'artistic touch' from the author, but not relevant to the solution). I'd prefer the problem with less material on the board instead.
Same solution.
18 Jun 05
Originally posted by BigDoggProblemThis is illegal however since the bishop at h1 cannot get there if there is/was a white pawn at g2.
That's right, ilywrin. Two ep captures must have occurred for the position to be legal. The problem was composed by Pal Benko and appeared in StrateGems in 1999.
Pa4 and Nf7 appear to be only needed for the finale to be mate. (An 'artistic touch' from the author, but not relevant to the solution). I'd prefer the problem with less material on the board instead.
[fen]8/8/2kP1r2/7b/8/6KP/7r/2R4B[/fen]
Same solution.
18 Jun 05
2 edits
Originally posted by ilywrinD'oh! Unfortunately, this means I'm stuck with something like...
This is illegal however since the bishop at h1 cannot get there if there is/was a white pawn at g2.
I have to use Ng2 because after -1.axb6ep+ b7-b5 -2.Kd3xPe3+ dxe3ep+ -3.e2-e4, a Pg2 would make the position illegal again (Rf2 no exit!).
19 Jun 05
1 edit
Originally posted by BigDoggProblemAnd you need a White piece at g2, why exactly?
D'oh! Unfortunately, this means I'm stuck with something like...
[fen]8/8/kP1r4/5b2/8/4KP2/5rN1/R4B2 b - - 0 3[/fen]
I have to use Ng2 because after -1.axb6ep+ b7-b5 -2.Kd3xPe3+ dxe3ep+ -3.e2-e4, a Pg2 would make the position illegal again (Rf2 no exit!).
EDIT: Nevermind just saw it 😉