I like it, I got one.
Illegal Position Contest!
Sort:
Chesspro5747 wrote:
#8432
White's e-pawn and h-pawn have together made five captures on light squares. In addition White captured both the black bishops, for a total of seven captures. Black still has ten units on the board, and must have started with 17 units. That's illegal.
Feb 11, 2024
0
#8387
@EvinSung Position is illegal because Black's last move must have been Rxb8+ and White has no legal last move.
amrugg wrote:
@EvinSung Position is illegal because Black's last move must have been Rxb8+ and White has no legal last move.
What about the other position?
Feb 11, 2024
0
#8389
n9531l1 wrote:
amrugg wrote:
@EvinSung Position is illegal because Black's last move must have been Rxb8+ and White has no legal last move.
What about the other position?
Oh I didn't see that. For some reason they both showed up the same. The position where everything is flipped is illegal because White's in illegal double-check.
amrugg wrote:
@EvinSung Position is illegal because Black's last move must have been Rxb8+ and White has no legal last move.
After Black retracts Rxb8+, how do we rule out White's possible retractions? Retracting a rook, bishop, or knight move gives an illegal retrocheck. Retracting Pc2-c3 locks the white bishop out of a2. Retracting Pc2xb3 puts an illegal pawn at c3.
idunnobro813 wrote:
spamming random stuff maybe illegal i dunno
I like seeing someone choose an appropriate screen name.
My username is the best.
idunnobro813 wrote:
#8329
Positions with both kings in check are not interesting.
EvinSung wrote:
White has 2 light squared bishops which means it promoted one pawn on a light square. It must come from either White's d or e pawn.
White could not have promoted on e8 or else it would not be able to get to a2 or f1 without capturing the d7 or f7 pawn. It could not have promoted on c8 or a8 either as that would require 3 or more captures, where black has 14 pieces on the board. Thus it would have to promote its pawn on g8, and since it can only make 2 captures, it needs to do so after Black's g7 pawn moves to g6(or captures on h6).
If g7 pawn moves to g6, White's promoted bishop on g8 cannot leave g8 and h7 without capturing the g6 and f7 pawns. If g7 pawn captures on h6, White's promoted bishop on g8 cannot leave g8 until Black plays hxg6, after which it is stuck between g8 and h7, a contradiction, therefore this is illegal
@DaStrwbrry, right way up the position is illegal. The last move had to be an enpassant but before f7f5, it would be black to play with white in check. Upside down, the last move had to be d5-d6+ because an enpassant would block white’s bishop from getting there, but then black does not have a legal last move since the king would be in an impossible double check anywhere it could have moved from and the pawns are in their starting ranks.
Well done! I thought it would be funny to post the “same” position but with different coordinates. I wonder how many more positions like these could be made where either orientation of the board is illegal, with different reasons in each case.