Bhb7+

Pawn promotion...

I think I have done it once, but I could use a diagram to know for sure

A bishop pair can never land on the same square. It's an impossible move because the h in Bhb7+ is incorrect. Normally a notation like that would signify which piece to move (which rook or which knight). But with Bishops this extra notation is never required as they can never land on the same square....

it has been a long time as I think about, but I can't decide, the longer I think about it the less likey it seems possible

Bhb7+ is impossible because the diagonalse from b7 are'nt touching the same rank twice while one of the files is the h file...

there could always be a probotion to prevent stalemate...

that is what I was thinking I had done, but I still need a diagram to refresh my memory

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

by the way, for the begginers that might ask, the position is drawn... 

It would take what would probably be a pretty pointless under-promotion, but the move is possible, as the diagram shows.

As a side-note... do you like my pretty cluster of pointless pawns on the kingside? I just got pawn happy making the diagram. Please enjoy...

[AARGH! While I was coming up with this, someone else has solved it. Not fast enough on the draw I guess.]

Not impossible, just weird. The final position took a bit of thinking, until I realized that the bishops had to be on the same diagonal (not one on h1 and another on a6 or c8). The key is, of course, pawn promotion.

 And in case you think this is not a legal position, here is the "proof game" (an absurdity, of course, but this demonstrates that the position can be reached by legal methods).

1. e4 d5 2. exd5 Qxd5 3. Nc3 e5 4. Nxd5 Nf6 5. Nxf6+ gxf6 6. d4 exd4 7. Bf4 Bg4
8. Bxc7 Bxd1 9. Bxb8 Bxc2 10. Bxa7 Rxa7 11. Nf3 Bb1 12. Nxd4 Bxa2 13. g4 f5 14.
Rxa2 Rxa2 15. Nxf5 Rxb2 16. Nd6+ Bxd6 17. f4 Rxh2 18. Rxh2 Kd8 19. Rxh7 Kc8 20.
Rxf7 Bxf4 21. g5 Rd8 22. Rd7 Rxd7 23. g6 Rd1+ 24. Kxd1 Bc7 25. g7 b6 26. g8=B
Bb8 27. Bd5 Bc7 28. Ba6+ Kb8 29. Bh1 Be5 30. Bab7 Bd6 31. Ba8 Kc8 32. Bhb7+ *

Dimknight... excellent proof game. It's funny the things we spend our energy on isnt' it?

It's all chess.... it's all good.

Boring304 makes a good point though... I think in our positions the correct notation would actually be B1b7+ instead of Bhb7+. 

Boring.. can you confirm this? (or anyone else more notation savvy than myself)

Ain't it the truth? By the way, a tip of the hat to you, Oginschile!

 

PS: The game I posted is copied directly from my PGN reader (two, actually), each of which uses Bhb7+ as the notation. Though admittedly, B1b7+ is equally unambiguous in this position.

Hey fellas.....go study rook endings and leave this nonense alone! You will reap much better rewards!

Ahh.. then according to the PGN readers... Bhb7+ would be correct.

We can officially pat ourselves on our respective backs.

yeah Bhb7 dont exists.

This is a cool move...

Anyone ever seen/done it before? (Just while we're on the topic of  unusual moves

There are some games knight promoting to a smothered mate.

This is a famous example of underpromotion to a knight with mate:

Wow. I guess that's it then.