Mate In 19 Moves!

Here’s a long problem of mine that was published earlier on superproblem.com

It’s White to mate in 19 moves!

Sorry but all those black or whie pawns couldn't have by passed each other.

Yes they could have. It is a legal position. Work is out!

Good one! And correct! Remarkably, there appears to be an unambiguous #21 if you remove "Pg5" but I like your solution better!

fg3 makes 4 the stronger name

Thanks @Arisktotle! The #19 was a bit of a monster to construct. The main intent of it is to show a record for the most queen promotions by White and Black together.

Also, what’s so likeable about my solution? I would like to see the #21.

Seeing this problem, now I know how Syssiphys felt when they showed him the mountain and the rock.

I got it from engine analysis. I often break up positions in small portions to zoom in on the intricacies of a certain phase of the solution. The complete meal is too large to swallow in one bite. In this particular case I removed pawn g5 and then analyzed it with only the black g- and h- pawn remaining on the 7th rank. To my surprise it rendered one unique sequence which completed on "move 21" (moves added for the missing pawns). However the final moves in this version are really hard to find and they only distract from the main theme which are the queen promotions. So I much prefer your solution with the subtle pawn move f5-f6 near the end plus the nice pawn mate!

@Arisktotle I'll go test it myself then. And the unexpected pawn move after such a barrage is indeed a nice touch. I do have some schemes that allow 2+7 Queen promotions, but so far a dual-free form eludes me.

Yes, it is all about finding a workable scheme with a repetitive pattern. Of course that is quite hard with all the heavy artillery potential on the board!