Shortest-proof-game challenge

To be honest, I wasn't even trying to get the fastest way, I was trying to get a way.

But you had a proof game before you posted the position. That's a good thing. I wish everyone here would do the same.

I do 11.5/12.0.

Like the Ke1# challenge this one is not optimal for a white start. Half a move can be gained when black makes the first e.p. capture in RewanDemontay's version.

Not really weird. Whoever said that just wants the game to end in a full move, not so crazy

Retro-problems don't care much about full moves. As many SPG's end with a white as with a black move. The formulation of the challenge becomes a bit more abstract though: "Find the shortest proof game where checkmate is delivered by a king making a capture on it's home square". Really highbrow!

Btw, Ke1# always ends up as a half move as all white moves do! You are used to challenges where only the white moves are counted - like #13 - but proof game challenges need to be more precise!

That's pretty interesting! RewanDemontay's version with the black start is 11.0/11.5:

Proof game in 36.0 or less.

I can do it in 33.5

33.0 feels reachable, but I already spent way too long on this position

23.5

Find the fastest game where castling, playing en passant, and underpromoting to a knight are all checkmate.

That's the (non-unique) SPG.

Here's a game, might be shorter.

When are we going to be able to have crazy house rules ? Or player made chaos?

You can choose the rules for positions you post here. There's no guarantee others here will be interested in them.

I do it in 12.0.

Man, you guys are killing it with these specific challenges!

Looks like the formatting preferences still aren't being saved contrary to Martin's claims. Here's the last position I posted:

I call it the "rook rage" checkmate. Normal Shortest game challenge for this one!