Legal or illegal?

A position is legal if it can be reached in a regular game.

Legal or illegal?  You decide.  :)  I will post my explanation in a couple days or so to give time to those that want time to think.  I created the puzzle.

Hmmm, let me think...

:)

Last move by white was Nh6++. I do not see anything illegal in this position.

Now if you are talking about silly and stupid moves they are not illegal, as far as I know.

how did white get 2 h-pawns there ?

Is it cheating if I used published sources to get the answer? :-) 

(For the benefit of everyone some of us have seen this in our group forum already)

impossible.. as Streptomicin said, white's last move have to be Nfh6, which means with the knight on f7 there was a move for black to enter this position - non of black pieces can stand on another square without check

Your question should be phrased: "is it Legal or illegal ...?"

(Discussions about cheating are now directed into this group - cheating-forum)  

Silly moves are legal.  :)

That is true Boring304.

Only move before Nh6++ for black was Bc7-Bc8 - not possible, Ne6 - Ng5, or Ne6 - Nf8. Black King could not have been on a8 as it would be in check by white N on f7.

So I vote no, this position could not be reached by normal play.

That is an interesting question.  The thought about how they got there does give an idea if it is legal or not.

The pawn at h3 is there so we could know that N did not jump to g5 from there. There could be any piece, B, Q. That is not relevant.

I think it's illegal:

1.White's last move must have been Nf7-h6++.

2.There are two moves that Black may have done before that, others would have meant White was in check; they are Kh8-g8 and d5xe4. Kh8-g8 would mean that White's last move before that was Nh6-f7+, that's just a repetition -- the position can't have been reached this way. So Black's last move was d5xe4.

3.Look at white's pawns -- two h pawns, pawns on files d-g: that must have taken five captures - c moves to d, d moves to e, etc. There are five Black pieces missing, so white has made no other captures.

4.Look at black's pawns before d5xe4: that must have taken two captures (dxc6 or dxc5, and exd6 or exd5, plus d5xe4 makes three. There are three White pieces missing.

5.BUT!! One of the white pieces missing is the a-pawn. The pawn capture occurred on c6, c5, d6 or d5, and white's a-pawn hasn't captured anything itself.

The a-pawn must have been captured on one of those squares but can't have reached them. This is a contradiction, so the position is illegal.

EDIT: Crap, Black's move might also have been bxc5. But in that case Black's pawns must also have at least three captures, cxb6, bxc5 and dxc6. Again, none of those captures can have taken the a-pawn, and otherwise there are only two pieces missing.

EDIT 2: Black's last move also can't have been c7-c6, because of how did the Black bishop end up on b8 then.

EDIT 3: By the way, pretty awesome problem! Must have taken a lot of work to get it all to fit so neatly.

bloody hell how you managed to work all that out !!

I think this position can be achieved with legal moves in normal play.

The following could be two alternatives

1.In the previous move the white knight (the "h" one) is on f7, Black king on h8 and now black moved Kh8-g8 and now White plays Nh6+ leading to the current position.

2.In the previous move the white knight (the "h" one) is on f7, Black king on g8, Black knight (either one) on e6 and now Black plays Nef8 or Neg6 followed by white Nh6 leading to the current position.

Cheers,

Ahhca, black could not play Nef8 or Neg5, as they would have to come to their current spots from Ne6, and that would make Whites King in check, and White king could not be where he is now.

How did White king sit there at d8?

 You've seen my games? :P

Heh, I remember this from the previous illegal positions thread. I think you made some small changes though?

Oops sorry... Thanks for clarifying that streptomicin :). Overlooked that.

Cheers,