Shortest-proof-game challenge

SPGs in 16.0.

Seems we both confirmed the duals.

Since there are so many more SPGs, is "duals" the right word? I guess we could say the "multiples".

There's no need to put too fine a point on it. One dual is too many for SPG's.

I do like this concept of an (almost) excelsior SPG where a pawn captures all the way to the back rank. I don't suppose our experts know of any?

That will be a good one if someone can find it. Here's a position with a unique SPG including an Excelsior white and a pawn that needs a non-capture move before capturing all the way to the back rank.

I tried to make this position more fun to solve (than another version I made), but that may make this cooked. Mostly confident that it is unique, though.

SPGs in 15.5.

I was able to find this one:

D. Pronkin, Rex Multiplex 1985

Proof Game in 29.5 moves

C+

Edit: not quite! It's not a capture onto the back rank. Stay tuned...

[and feel free to solve it anyway, if you can]

This time I really found it. Short and to the point.

Hitoshi Yanami 
PR01 Problem Paradise 04-06/1998

PG in 12.0 moves [C+]

An impressive find.

Well, alright then. Here's that other version that I made which I've computer checked.

Clever.

I think the really clever ones are #6772 found by BigDoggProblem and #6774 composed by Leither123.

Captureless proof game.

Unique SPG in 21.0.

Here's another captureless proof game. I think it holds the current move length record for a capture-free unique SPG.