Some selfmates I've made

#19 just appeared out of nowhere..... #20 is the selfmating proposition

white's objective is to reduce black's forces until they can be ignored completely while the selfmating tableau is put in place... (More than one hundred moves are required for white to execute the first capture)

Are there chess problems defying solution by humans and machines?

generally, such long solutions are surely beyond my abilities!

White to move and force black to win in 12

it seems one quite difficult problem.
With the black side, which should spend at least 6 plies to promote the pawn, obligatory for a checkmate, with also a necessary precondition that black should be forced not to underpromote his pawn, and with white being necessary to offer at least some pieces but also probably to move his king close to the whole action, I can't find a forced solution. If possible, please do share a pgn with one solution

I could just force the black pawn to move towards promotion like this...

Here is that twelve-move sequence....
White Black
1. Bg6+ 1. Kf8
2. Bh6+ 2. Kg8
3. f7+ 3. Kh8
4. Qf6+ 4. NxQ
5. f8=Q+ 5. Ng8
6. Rh4 6. b6
7. Rg5 7. b5
8. Ke2 8. b4
9. Kf3 9. b3
10. Kg4 10. b2
11. Kh5 11. b1=?
12. Qf6+ 12. NxQ mate

beautiful confinement!

https://www.chess.com/forum/view/general/hardest-chess-puzzle-3#comment-103903483 Please click on the poor link

#14. selfmate in 2

These are stupid.

this actually helps your imagination

perhaps they aren't that good, don't know. But surely they make me feel creative, while thinking on them

plus if you think these are stupid, just leave no need to post comments like these

thank you!

Introuble2, I'm on the verge of making a podcast to show a few of the most interesting selfmates I've discovered over the past 50 years. This guy 654Psyfox calling selfmates stupid makes me suspect the case for selfmates hasn't been convincingly made. I make this challenge to psyfox: From the start of a regulation game against psy I will take white and force him to win the game. Bob Linsley

please do inform, about this collection of selfmate problems, whenever is ready to be exposed!

Introuble2 I've been in prison for more than fifty years and admittedly have my hands full just trying to use a cellphone.. While trying to contact the chess world my hunt and peck tactics led to you... and maybe no one else. In 1969, while dwelling in a south block dungeon in San Quentin, I chanced upon the concept of forcing the opponent to win. To win a game of chess your task is to gain absolute control of the opposing King..... to force the opponent to win you must gain absolute control of every piece on the board. From that hole in the ground I emerged with a simple self mating concoction which to this day has won hundreds of wagers and although it was the first of dozens of gambling propositions I've conjured up over the decades it has proven to be the most "irresistible" weapon in the arsenal. I had a chance to show this selfmate to GM Jay Whitehead after his son had just beaten me in a 24board simultaneous exhibition in Quentin. After seeing it executed, the GM's first response was to his son. He said, "That just goes to show you, you never know when you're going to learn something new." Considering Mr. Whitehead's prominence in the chess world, that remark inspired me to spend the next five decades exploring and creating chess hustles, most of which incorporate selfmate.