Shortest-proof-game challenge

I don't know if anyone is working on my position, but I thought I should add that I made this with an intended solution of 16.5, and I just got tired of searching for duals 😅

So if you find a solution in 16.5, I'd love to see it!

Oops I did it twice

No duals found.

Nice! As you can probably tell, I really liked the idea of zigzagging pieces ˙ᵕ˙

You might enjoy this one.

R McCracken

Probleemblad 2003

Proof game in 20.5

Thanks for the challenge! That was indeed quite fun; very nice zigzag across the top.

I don't think I can make something that complex, but hopefully this is mildly interesting

Here's a first try. How much shorter does it need to be?

Ah yes, I forgot to include that. PG in 10.5

I suppose this is the PG in 10.5.

Yep, this time with a boomerang knight

Here's a position I found on reddit. PG in 9.0

This was a little easier.

Now that the Babson Task has finally been achieved in an endgame study [1], the question remains how quickly the position can be reached:

[1] https://en.chessbase.com/post/babson-task-modern-realization

I don't know if anyone is working on your position with 16 queens, but if so, here's a game I made with 18 queens that might be helpful.

33.0 moves should be the quickest, although it isn't a unique SPG.

Thanks for providing the short proof game! The chessbase article notes the study's "perfect economy (no promoted pieces in the diagram)", so I guess it would be nice to have a proof game without promotions as well.

I don't think it is possible to have a proof game without promotions here.

Black's captures are cxd and dxe twice. As for white's captures, we must first observe that one of white's fgh pawns was captured on the d/e files without promotion, and that black's g-pawn never left its file (which requires white's g-pawn to capture at least once). With these considerations, the minimum number of white captures is 5: bxa, exd, fxe, gxh and hxg. Black is missing 5 pieces, but one of them includes the b-pawn, and the only way for it to get captured is to first promote on b1 (without capture). Thus a promotion must have occurred.

Regardless, the promoted piece in my proof game was captured, which means there are no promoted pieces in the diagram.