Illegal Position Contest!

I suppose there must be, in the whole world of chess players,  enough people who are stimulated by the intellectual challenges provided by these kinds of problems.

also after like 2 weeks the "contest" part was just gone

I've been trying to find positions that are hard to prove illegal. I thought I had done so with the position at #4566, but tacticspotter figured it out the same day. Let's see how long it takes someone to give a convincing proof that this new position is illegal.

hmm axb3 duh dxcxb4 duh exdxcxb5 duh fxexdxcxbxa7 duh add blacks 5 remaining pieces and black has 16 pieces. but whites g pawn needs to promote(for the second queen) but it needs to capture to do so. or does it? black could have played gxf6 to let whites pawn pass then fxg5 and fxgwhatever. so white has 14 pieces on board and 3 have to have been captured so illegal.

(If whites g pawn captured then black has to have 17 pieces.)

just a counting exercise

33 pieces are required on board is the summary so illegal

So this was another one that was too easy. White's pawns used all 11 available captures to get into place, so the g-pawn has to promote without capturing. But Black needs three captures for one pawn to leave and two pawns to return to the g-file, and Black has only two available captures.

I'll see if I can find a harder one.

26 minutes

I'm hoping I can find one that takes you at least 30 minutes.

well i really saw it around 10-20 minutes after you posted and typed with 1 finger from 1 hand super slowly

Here's a position that was published as a valid mate in 2 problem and later found to be illegal. See how long it takes to prove illegality. You're allowed to type fast with both hands if you like. Then see how long it takes you to solve it as a White to play and mate in 2 problem.

lol no i wont try to prove illegality here

i want others to try

There won't be any others from me until someone tackles this one.

The illegal thing is that the white pond on g5 is in the same line as a black one, so it must have taken some piece, but black has not lost and piece so far. ( Sry for my bad english)

Precisely

Your English is fine but your explanation is incorrect. Black's c-pawn can capture White's d-pawn on d6 and then promote to a piece to be captured by the white h-pawn on g5 after the black g-pawn has reached the 4th rank.

Precisely

P.S. Is this copywrite?

No, it's in the public domain.

No this is copyright