possible or impossible?

don't forget Shoopi's puzzles and here's one of my own:

you're right piphilologist!

this one looks the same and is as easy as the previous one

Yes, there is!

Well, not really a "trick", but there is a way for white to have a legal last move with his king. You need to look back more than one move, though. You're thinking, if a square is threatened by at least 2 black pieces, there's no way that the white king came from that square. But it is possible - black had a discovered double check, which is the only possible sequence leading to the final position.

I still don't get it. If there wasn't a knight on h7 then N on e7, K on f8, 1...Ne7-g6++ 2.Kg7 but in the diagram f8 would be impossible triple check. The only other possibility is f7, but again it is impossible double check. I really don't see how either position can be legal

What about g8?

The first one is possible, all you need is 6 black minor pieces sacrificed to move the pawns into position like that for white and 1 more to get another white bishop on the black square

What? I'm talking about diagram 2, which you say is legal. If it's black to move white has just moved; he can't have moved from a square that has a piece on. Like I said earlier it would be possible if it was white to move because of B on c4 and N on d5 and K on g8, 1...Nf6++ 2.Kg7 Bg8

Did you put "Black to move" by mistake?

Oh right, I had looked at the position again and I have mislead you a bit before. Turns out white actually can have a last move with a pawn. Sorry for the confusion

Oh yeah I get it now thats for clarifying that.

5 spare white pieces

the d-pawn took a piece on the e-file and the f-pawn

c-pawn took a piece on b2

at least one pawn queened on a1 to another dark bishop therefore a-pawn x b x a and b-pawn x a

therefore a3 played first, then a and b pawns queen, then b3 and c-pawn queens

therefore only 1 spare pawn move (a3-a4)

So the last moves were 1...Nd5-f6++ 2.Kg7 Bg8 3.a4

and position 1 is illegal because Rook prevents the bishop coming from c4

nice position :)

That's right! Finally that one is solved hehe...

To celebrate, here are two easier puzzles, composed by me.

Can white castle?

1st puzzle white can castle, white h-pawn take black rook and promotes on g-file, black g-pawn takes 5 pieces (Q,R,N,dark-squareB,promoted pawn) promotes on b1 with White Knight on d1, black B goes to c1 freeing the knight which goes to b1, black bishop goes back to f8

2nd white can't castle, black h-pawn takes 5 white pieces (Q,R,B,N,c-pawn) promotes when the white N is on d1 but white N can't get to b1

It is usually prefered that you add a proof game when declaring a position legal. I know that it is a bit of a hassle though. Anyway your analysis for 1st puzzle seems absolutely fine, you made short work of it. Good job.

The second position is legal too though. There is one thing you didn't consider.

Ok ill edit in a game later I was just looking at it quickly I would usually put a game in.

Woah it's the black king that I didnt consider isn't it

Well done! will post more puzzles tomorrow. You can rest for now :P

I don't understand how you get rid of the white light-square B in puzzle 1. It's not possible to put it on g8. Therefore, white has to move his rook to give time to black to take B. So white can't castle.

Maybe I'm missing something.

I can't figure out how white can get rid of the rest of his tempo, unless he moves the rook or king.

Impossible. White's last move had to be e5-e6, which would have begun with Black in check.