Is this a record topping the 14-move one? I didn't get exactly what that record was about. Can you explain? I once made an endgame study with 5 queen sacrifices in a similar mechanism like Kg1-h2-g1. Not good enough for the record books I suppose 
A Monster Mate In 20
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Yes, it tops the 14-mover. My twenty-mover sets a new record for the most queen promotions in a direcmate by both sides combined. The 7th Black promotion into a knight was a nice addition that I managed to throw in. It was difficult, since these probems hinge barely on legality. I also have the record for 2+5 knight promotions;
Black's promotion mechansim is an old one that I found in an this old problem-https://www.yacpdb.org/#192553-after seeing a reprint of it in some old Feenscach issue-I can't remember which one. The 6th Black queening and the White's promotions are my work.
Can you show the study that you mentioned?
Found it! Only 4 queen sacrifces (1 near the end), the 5 were in an earlier version. Two of the queen sacs show your theme, the other two were sacs by the opposite side. But during the solution every piece on the board is sacrficed; there are no simple exchanges!
https://www.chess.com/forum/view/endgames/a-hard-endgame-for-who#comment-42088546
Thanks Arisktotle! Reminds me of that famous problem with 3 queen sacrifices on each side in a drawing problem-https://www.yacpdb.org/#275806
Also, I know it's less than a day since I made the 4+6 record, but I've had a divine revelation on how to get 4+7 queen promotions! I'm experimenting to find a legal and correct postion at this very moment.
hurray!
Good one
Good one, black somehow always do 'silly' and 'what-are-you-even-doing' moves. I like them! Hahahahahaha.
RewanDemontay wrote:
Thanks Arisktotle! Reminds me of that famous problem with 3 queen sacrifices on each side in a drawing problem-https://www.yacpdb.org/#275806
Also, I know it's less than a day since I made the 4+6 record, but I've had a divine revelation on how to get 4+7 queen promotions! I'm experimenting to find a legal and correct postion at this very moment.
That is a great Queen sac study! In mine the sacs are sort of an introduction to the central theme but here they are the theme and such a fascinating strategy! I love the logic!
Divine revelations will start to occur when you are on a subject you love and stay on it long enough. At some point the lights in the tunnel will turn on and help you to the exit. If you stop believing that then you will quit 10 minutes early!
I found a solution that takes 5 moves
fxg8=Q , a1=R , Kh2 Rxg8 , hxg8=Q Bb6 , Rh6 e1=Q , Qe8#
Jul 3, 2021
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#12
ayyaaya wrote:
I found a solution that takes 5 moves
fxg8=Q , a1=R , Kh2 Rxg8 , hxg8=Q Bb6 , Rh6 e1=Q , Qe8#
Nope, in a forced-mate problem, you have to find the best black moves that delay the mate the longest. If you make Black choose a bad move like 3...Bb6? then of course White could mate sooner (not 4.Rh6? either but 4.Qe8 mate).
Jul 3, 2021
0
#13
Clever. Also fun fact: Stockfish 12 depth=24 mistakenly thinks it's a draw.
Which is kind of surprising, really. Black has very few moves that don't give white M1.
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However, I would make black's first move be 1... a1=Q+. Doesn't affect the 20-move outcome, but I think it makes "more sense".
I've recently created this beautitul checkmate problem. Try and solve it!